Open Source Ecology - User contributions [en]

User:Mransaw

2025-08-10T17:17:58Z

Mransaw:

I'm an Electronics Technologist and Electrical & Computer Engineering student who is interested in sustainable technologies, permaculture, and agriculture/agroforestry. Anything involving food production or cyclical systems is very interesting to me. I have some experience with organic farming as well (maintaining 1 acre market garden and livestock). Some additional credentials/skills:
- small-scale mushroom production
- basic beekeeping
- building electronic circuits/systems
- programming in C(++), Python, JavaScript, YAML

Miles Log

2022-07-17T05:00:18Z

Mransaw:

<html><iframe width="600" height="300" src="https://osedev.org/wiki/Miles?start=3/1/2018"></iframe></html>

{{RightTOC}}
=Sat Jul 16, 2022=
Researched open source inverters:
https://github.com/transistorgrab/OSSI
https://github.com/SDI-SoftwareDefinedInverter/TAPAS

=Wed Dec 26, 2018=
Simplified [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck-Boost_Converter buck/boost converter design] and made [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck.2FBoost_Converter_Module bill of materials]

=Sun Dec 16, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#General Learning about 555 Timers and PWM]

=Mon Nov 19, 2018=
Learning about PWM and [https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator astable multivibrators]

=Sun Nov 11, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck-Boost_Converter Added control wiring to buck-boost converter draft design]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Calculations Studying voltage follower circuits to increase input impedance of ADC]

=Sun Nov 4, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck-Boost_Converter Working on buck-boost converter draft design]

=Fri Oct 26, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck-Boost_Converter_2 component selection for buck-boost converter]

=Mon Oct 1, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck-Boost_Converter Started draft design of 1.5kW buck-boost converter]

=Sun Sep 30, 2018=
Found [http://kicad.rohrbacher.net/quicklib.php KiCad symbol generator] and made [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Conceptual_Design symbol for PWM controller]

Learning how to implement [http://rohmfs.rohm.com/en/products/databook/datasheet/ic/power/switching_regulator/bd9850fvm-e.pdf PWM controller IC]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Design_buck.2Fboost_converter_circuit.2Fmodule Brainstorming ways to increase PWM frequency]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Calculations Doing calculations for buck-boost converter]

=Wed Sep 26, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Voltage_Conversion Researched buck-boost topologies]

=Tue Sep 25, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#General Researched Isolation in Digital Power Supplies]

=Mon Sep 24, 2018=
Circuit diagram and cost estimate for [https://wiki.opensourceecology.org/wiki/Current_Meeting current meeting]

Added possible parts to [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Forward_Configuration forward configuration]

=Sun Sep 23, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Figure_out_ways_to_salvage_or_build_transformers Reassessed flyback configuration] and [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Research organized research section]

=Sat Sep 22, 2018=
[http://www.ti.com/lit/ds/symlink/ucc28780.pdf learning about active flyback controller IC] and [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration_2 component selection]

=Wed Sep 19, 2018=
[http://www.ti.com/lit/ds/symlink/ucc28780.pdf learning how to use active clamp flyback controller IC]

=Mon Sep 17, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Research learning about gate drivers] and estimated cost of power supply components to be around $70 for the flyback configuration, not including the microcontroller and display

=Fri Sep 14, 2018=
Learning about active snubbers, [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration_2 found an IC to control them]

=Wed Sep 12, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Research Learning about lossless snubber circuits]

=Tue Sep 11, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration_2 selected some parts for flyback configuration of power supply]

found possible toroid powder core for flyback transformer

=Sun Sep 9, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration selected a possible core for flyback transformer]

=Sat Sep 8, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Transformer Learning about Flyback Transformer Design]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration Selected some possible parts for prototype]

=Wed Sep 5, 2018=
learning about buck-boost converters, [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Research flyback transformer design], and [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Possible_Parts component selection]

=Tue Sep 4, 2018=
[https://wiki.opensourceecology.org/wiki/Qucs#Running_the_Above_Simulation:_More_Details How to install Qucs-S]

=Sun Sep 2, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Figure_out_ways_to_salvage_or_build_transformers Learned about buck-boost converters and new possibilities for flyback transformers enabled by advancements in MOSFET technology]

=Wed Aug 29, 2018=
[http://www.ti.com/lit/an/slva059a/slva059a.pdf Learned about buck-boost power stages]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#To_Do.2FIn_Progress Made to do/in progress list]

=Tue Aug 28, 2018=
Talked with Jesse to brainstorm and plan next steps

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Software Created Git repository for microcontroller code]

=Mon Aug 27, 2018=
Learning about [https://www.academia.edu/36721604/RepRapable_Recyclebot_Open_source_3-D_printable_extruder_for_converting_plastic_to_3-D_printing_filament RecycleBot] and [https://en.wikipedia.org/wiki/PID_controller PID controllers]

=Sat Aug 25, 2018=
[https://wiki.opensourceecology.org/wiki/Qucs Made wiki page for Qucs]

Quc-S Simulation: {{YoutubePopup|SQkO3aYBCuk}}

=Thu Aug 23, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08 Adjustable Power Supply]

[https://www.digikey.com/short/jfnv75 Transformer], [https://www.digikey.com/short/jfnvtc Rectifier]

=Tue Aug 21, 2018=
[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08#Isolated Started BoM for Isolated Arduino Power Supply]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08#Prototyping Prototyped Non-isolated Arduino Power Supply, successfully produced 10V @ 380mA from 120Vac]

=Mon Aug 20, 2018=
<html><iframe src="https://docs.google.com/presentation/d/e/2PACX-1vTx4K6wvVdWwHGxGWjYOPPy4fUNDUj6HDOviTvzn8LSUzpZ5vf0IsRBg8UQxb4jbNPNayP32iX5rRdz/embed?start=false&loop=false&delayms=3000" frameborder="0" width="960" height="569" allowfullscreen="true" mozallowfullscreen="true" webkitallowfullscreen="true"></iframe></html>

[https://docs.google.com/presentation/d/1Y1zsd6oYwKa1JdSXy3bzswW5YfVC6J6c6HS8PW8RtUk/edit?usp=sharing ^edit^]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08#QUCS-S_Simulation Arduino Power Supply Simulation]

=Sat Aug 18, 2018=
[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08#Calculations Calculations for Arduino Power Supply]

=Fri Aug 17, 2018=
[https://wiki.opensourceecology.org/index.php?title=Arduino_Power_Supply_v18.08 Arduino Power Supply]

=Thu Aug 16, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Bill_of_Materials#BoM_for_Non-isolated_9V_Power_Supply_.28280_mA.29 BoM for Arduino power supply and voltage reference circuit]

=Wed Aug 15, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Qucs-s_Simulations Simulated non-isolated power supply for Arduino Mega]

=Tue Aug 14, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Qucs-s_Simulations Creating simulation of non-isolated power supply for Arduino Mega]

R&D for power supply to Arduino: [[Universal_Power_Supply/Bill_of_Materials#BoM_for_20W_Power_Supply_.2Fw_12_DC_Output]]

=Sun 12, 2018=
[http://ngspice.sourceforge.net/docs/ngspice-manual.pdf Learning about OpenMP with Ngspice for multi-core circuit simulation]

Updated [https://drive.google.com/drive/folders/15Kk7HLIvO4MyOILj4dJSY45LwgANmcUd?usp=sharing Power Supply Simulation].

Learning how to enable [https://sourceforge.net/p/ngspice/mailman/message/32611983/ multi-core processing to speed up simulation time].

=Sat Aug 11, 2018=
Installed [https://ra3xdh.github.io/ Qucs-s (Qucs with Spice)] to do transient analysis of circuits

=Fri Aug 10, 2018=
[https://drive.google.com/drive/folders/1jgUGcGJyVH43yN_hhrippUOOm9ozlwb5?usp=sharing Learning Qucs to Simulate Power Supply]

=Wed Aug 8, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Initial_Design Initial Design of 800W Power Supply]

=Tue Aug 7, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Bill_of_Materials#BoM_for_800W_Power_Supply_.2Fw_12-24V_DC_Output Bill of Materials for 800W Power Supply]

=Fri Aug 3, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Possible_Parts Possible Parts for UPS]

=Wed Aug 1, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Power_Supply_R.26D Power Supply R&D]

=Tue Jul 31, 2018=
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing Universal Power Supply (UPS) Block Diagram]

Notes at [[Miles Work Meeting]]

=Fri Jul 27, 2018=
[https://drive.google.com/file/d/1UHHGPRdyM7k2f22uKXJk5aKurP5DX-7o/view?usp=sharing FreeCAD Test File]

{{YoutubePopup|kCk6uS-fRUY}}
OSE Developer Test Video

How many hours each part of the test took to complete:

1) Installing Linux: ~3h. Tried to do a full install onto USB stick but display wouldn't work.

2) Learning FreeCAD: 4h

3) Documenting your work: 2h

Learning FreeCAD was the most difficult task.

Other feedback: A sample FreeCAD file with a competed cube would be helpful as a reference.

Score: 100% of test points completed.

=Wed Jul 18, 2018=
[https://youtu.be/aDrMAVgLg8g Video cover letter for OSE Development Team]

=Mon Jul 16, 2018=
[https://drive.google.com/file/d/1vIKdj6wP_aisvoNAvM7GocePa6G3KLck/view?usp=sharing Video Cover Letter Prep]

Installed [[OSE Linux]] on USB stick.

=Sun Jul 15, 2018=
Requested account but didn't receive confirmation email, communicated with [[Marcin]] to get it working. [https://drive.google.com/file/d/1KmuKzSFBM1K2_-l8ISi56kYi1zcYRf6x/view?usp=drivesdk]

Adjustable Power Supply v18.08

2018-12-28T01:16:43Z

Mransaw: /* Modules */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement SPI to control [https://www.digikey.com/short/pcqbwv digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?).

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- design PCB
- research microcontroller options for voltage control and display

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

===Microcontroller===
* ~11 I/O pins for 7-segment display

* 2 I/o pins for rotary encoder and power switch

* at least 4 I/O pins for SPI control of digital potentiometer

* 1 ADC for output voltage sensing

* 5V output to power other ICs would be nice

'''minimum requirements:''' 17 I/O pins, 1 ADC

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Microcontroller===
[https://electronics.stackexchange.com/questions/167458/flash-and-eeprom Flash and EEPROM]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

[https://www.digikey.com/short/pcfvjt Similar DC/DC converter] with isolation but without adjustable output or display: ~$80

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>

[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1000 height=500></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg

[https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN] and 50 kOhm resistor, or [https://www.digikey.com/short/pcqbwv IC DGTL POT 100K SPI 16-TSSOP] and 2 x 16kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====User Interface=====
Microcontroller: [https://www.digikey.com/short/pcf1cb IC MCU 32BIT 64KB FLASH 44LGA] ($5, higher resolution ADC) or [https://www.digikey.com/short/pcf1tq IC MCU 32BIT 128KB FLASH 64LQFP] ($6, similar specs to Arduino Mega)

LCD: [https://www.digikey.com/short/pcfdpd LCD 4.5 DIGIT .4" TRANSFL]

BJTs: [https://www.digikey.com/short/pcfdp9 IC PWR RELAY N-CHAN U-DFN3030-10]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

=Bill of Materials=
==Buck/Boost Converter Module==
<html><iframe src="https://docs.google.com/spreadsheets/d/e/2PACX-1vRuPxZK24d7GdTwqzsNq4B9LgWyOsCs7YT73sC7Tw-9Zj6UBEbbaalxfD7FPRa9jBx9acQkj_Dh0Ln1/pubhtml?widget=true&headers=false" height=500 width=900></iframe></html>

[https://docs.google.com/spreadsheets/d/17jSD9Ku_RUkiSY8j9lGMdcOUFeJdl2H1anW0THEKH-g/edit?usp=sharing edit]

Adjustable Power Supply v18.08

2018-12-28T01:16:24Z

Mransaw: /* Flyback Configuration */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement SPI to control [https://www.digikey.com/short/pcqbwv digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?).

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- design PCB
- research microcontroller options for voltage control and display

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

===Microcontroller===
* ~11 I/O pins for 7-segment display

* 2 I/o pins for rotary encoder and power switch

* at least 4 I/O pins for SPI control of digital potentiometer

* 1 ADC for output voltage sensing

* 5V output to power other ICs would be nice

'''minimum requirements:''' 17 I/O pins, 1 ADC

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Microcontroller===
[https://electronics.stackexchange.com/questions/167458/flash-and-eeprom Flash and EEPROM]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

[https://www.digikey.com/short/pcfvjt Similar DC/DC converter] with isolation but without adjustable output or display: ~$80

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1000 height=500></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg

[https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN] and 50 kOhm resistor, or [https://www.digikey.com/short/pcqbwv IC DGTL POT 100K SPI 16-TSSOP] and 2 x 16kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====User Interface=====
Microcontroller: [https://www.digikey.com/short/pcf1cb IC MCU 32BIT 64KB FLASH 44LGA] ($5, higher resolution ADC) or [https://www.digikey.com/short/pcf1tq IC MCU 32BIT 128KB FLASH 64LQFP] ($6, similar specs to Arduino Mega)

LCD: [https://www.digikey.com/short/pcfdpd LCD 4.5 DIGIT .4" TRANSFL]

BJTs: [https://www.digikey.com/short/pcfdp9 IC PWR RELAY N-CHAN U-DFN3030-10]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

=Bill of Materials=
==Buck/Boost Converter Module==
<html><iframe src="https://docs.google.com/spreadsheets/d/e/2PACX-1vRuPxZK24d7GdTwqzsNq4B9LgWyOsCs7YT73sC7Tw-9Zj6UBEbbaalxfD7FPRa9jBx9acQkj_Dh0Ln1/pubhtml?widget=true&headers=false" height=500 width=900></iframe></html>

[https://docs.google.com/spreadsheets/d/17jSD9Ku_RUkiSY8j9lGMdcOUFeJdl2H1anW0THEKH-g/edit?usp=sharing edit]

Adjustable Power Supply v18.08

2018-12-28T00:42:29Z

Mransaw: /* Research */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement SPI to control [https://www.digikey.com/short/pcqbwv digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?).

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- design PCB
- research microcontroller options for voltage control and display

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

===Microcontroller===
* ~11 I/O pins for 7-segment display

* 2 I/o pins for rotary encoder and power switch

* at least 4 I/O pins for SPI control of digital potentiometer

* 1 ADC for output voltage sensing

* 5V output to power other ICs would be nice

'''minimum requirements:''' 17 I/O pins, 1 ADC

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Microcontroller===
[https://electronics.stackexchange.com/questions/167458/flash-and-eeprom Flash and EEPROM]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

[https://www.digikey.com/short/pcfvjt Similar DC/DC converter] with isolation but without adjustable output or display: ~$80

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1000 height=500></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN] and 50 kOhm resistor, or [https://www.digikey.com/short/pcqbwv IC DGTL POT 100K SPI 16-TSSOP] and 2 x 16kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====User Interface=====
Microcontroller: [https://www.digikey.com/short/pcf1cb IC MCU 32BIT 64KB FLASH 44LGA] ($5, higher resolution ADC) or [https://www.digikey.com/short/pcf1tq IC MCU 32BIT 128KB FLASH 64LQFP] ($6, similar specs to Arduino Mega)

LCD: [https://www.digikey.com/short/pcfdpd LCD 4.5 DIGIT .4" TRANSFL]

BJTs: [https://www.digikey.com/short/pcfdp9 IC PWR RELAY N-CHAN U-DFN3030-10]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

=Bill of Materials=
==Buck/Boost Converter Module==
<html><iframe src="https://docs.google.com/spreadsheets/d/e/2PACX-1vRuPxZK24d7GdTwqzsNq4B9LgWyOsCs7YT73sC7Tw-9Zj6UBEbbaalxfD7FPRa9jBx9acQkj_Dh0Ln1/pubhtml?widget=true&headers=false" height=500 width=900></iframe></html>

[https://docs.google.com/spreadsheets/d/17jSD9Ku_RUkiSY8j9lGMdcOUFeJdl2H1anW0THEKH-g/edit?usp=sharing edit]

Adjustable Power Supply v18.08

2018-12-28T00:31:36Z

Mransaw: /* User Interface */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement SPI to control [https://www.digikey.com/short/pcqbwv digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?).

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- design PCB
- research microcontroller options for voltage control and display

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

===Microcontroller===
* ~11 I/O pins for 7-segment display

* 2 I/o pins for rotary encoder and power switch

* at least 4 I/O pins for SPI control of digital potentiometer

* 1 ADC for output voltage sensing

* 5V output to power other ICs would be nice

'''minimum requirements:''' 17 I/O pins, 1 ADC

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

[https://www.digikey.com/short/pcfvjt Similar DC/DC converter] with isolation but without adjustable output or display: ~$80

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1000 height=500></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN] and 50 kOhm resistor, or [https://www.digikey.com/short/pcqbwv IC DGTL POT 100K SPI 16-TSSOP] and 2 x 16kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====User Interface=====
Microcontroller: [https://www.digikey.com/short/pcf1cb IC MCU 32BIT 64KB FLASH 44LGA] ($5, higher resolution ADC) or [https://www.digikey.com/short/pcf1tq IC MCU 32BIT 128KB FLASH 64LQFP] ($6, similar specs to Arduino Mega)

LCD: [https://www.digikey.com/short/pcfdpd LCD 4.5 DIGIT .4" TRANSFL]

BJTs: [https://www.digikey.com/short/pcfdp9 IC PWR RELAY N-CHAN U-DFN3030-10]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

=Bill of Materials=
==Buck/Boost Converter Module==
<html><iframe src="https://docs.google.com/spreadsheets/d/e/2PACX-1vRuPxZK24d7GdTwqzsNq4B9LgWyOsCs7YT73sC7Tw-9Zj6UBEbbaalxfD7FPRa9jBx9acQkj_Dh0Ln1/pubhtml?widget=true&headers=false" height=500 width=900></iframe></html>

[https://docs.google.com/spreadsheets/d/17jSD9Ku_RUkiSY8j9lGMdcOUFeJdl2H1anW0THEKH-g/edit?usp=sharing edit]

Adjustable Power Supply v18.08

2018-12-27T22:28:26Z

Mransaw: /* User Interface */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement SPI to control [https://www.digikey.com/short/pcqbwv digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?).

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- design PCB
- research microcontroller options for voltage control and display

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

===Microcontroller===
* ~11 I/O pins for 7-segment display

* 2 I/o pins for rotary encoder and power switch

* at least 4 I/O pins for SPI control of digital potentiometer

* 1 ADC for output voltage sensing

* 5V output to power other ICs would be nice

'''minimum requirements:''' 17 I/O pins, 1 ADC

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

[https://www.digikey.com/short/pcfvjt Similar DC/DC converter] with isolation but without adjustable output or display: ~$80

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1000 height=500></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN] and 50 kOhm resistor, or [https://www.digikey.com/short/pcqbwv IC DGTL POT 100K SPI 16-TSSOP] and 2 x 16kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====User Interface=====
Microcontroller: [https://www.digikey.com/short/pcf1cb IC MCU 32BIT 64KB FLASH 44LGA] ($4, higher resolution ADC) or [https://www.digikey.com/short/pcf1tq IC MCU 32BIT 128KB FLASH 64LQFP] ($6, similar specs to Arduino Mega)

LCD: [https://www.digikey.com/short/pcfdpd LCD 4.5 DIGIT .4" TRANSFL]

BJTs: [https://www.digikey.com/short/pcfdp9 IC PWR RELAY N-CHAN U-DFN3030-10]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

=Bill of Materials=
==Buck/Boost Converter Module==
<html><iframe src="https://docs.google.com/spreadsheets/d/e/2PACX-1vRuPxZK24d7GdTwqzsNq4B9LgWyOsCs7YT73sC7Tw-9Zj6UBEbbaalxfD7FPRa9jBx9acQkj_Dh0Ln1/pubhtml?widget=true&headers=false" height=500 width=900></iframe></html>

[https://docs.google.com/spreadsheets/d/17jSD9Ku_RUkiSY8j9lGMdcOUFeJdl2H1anW0THEKH-g/edit?usp=sharing edit]

Adjustable Power Supply v18.08

2018-12-27T22:27:48Z

Mransaw: /* User Interface */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement SPI to control [https://www.digikey.com/short/pcqbwv digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?).

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- design PCB
- research microcontroller options for voltage control and display

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

===Microcontroller===
* ~11 I/O pins for 7-segment display

* 2 I/o pins for rotary encoder and power switch

* at least 4 I/O pins for SPI control of digital potentiometer

* 1 ADC for output voltage sensing

* 5V output to power other ICs would be nice

'''minimum requirements:''' 17 I/O pins, 1 ADC

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

[https://www.digikey.com/short/pcfvjt Similar DC/DC converter] with isolation but without adjustable output or display: ~$80

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1000 height=500></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN] and 50 kOhm resistor, or [https://www.digikey.com/short/pcqbwv IC DGTL POT 100K SPI 16-TSSOP] and 2 x 16kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====User Interface=====
Microcontroller: [https://www.digikey.com/short/pcf1cb IC MCU 32BIT 64KB FLASH 44LGA] ($4, highest resolution ADC) or [https://www.digikey.com/short/pcf1tq IC MCU 32BIT 128KB FLASH 64LQFP] ($6, similar specs to Arduino Mega)

LCD: [https://www.digikey.com/short/pcfdpd LCD 4.5 DIGIT .4" TRANSFL]

BJTs: [https://www.digikey.com/short/pcfdp9 IC PWR RELAY N-CHAN U-DFN3030-10]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

=Bill of Materials=
==Buck/Boost Converter Module==
<html><iframe src="https://docs.google.com/spreadsheets/d/e/2PACX-1vRuPxZK24d7GdTwqzsNq4B9LgWyOsCs7YT73sC7Tw-9Zj6UBEbbaalxfD7FPRa9jBx9acQkj_Dh0Ln1/pubhtml?widget=true&headers=false" height=500 width=900></iframe></html>

[https://docs.google.com/spreadsheets/d/17jSD9Ku_RUkiSY8j9lGMdcOUFeJdl2H1anW0THEKH-g/edit?usp=sharing edit]

Adjustable Power Supply v18.08

2018-12-27T22:27:31Z

Mransaw: /* User Interface */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement SPI to control [https://www.digikey.com/short/pcqbwv digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?).

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- design PCB
- research microcontroller options for voltage control and display

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

===Microcontroller===
* ~11 I/O pins for 7-segment display

* 2 I/o pins for rotary encoder and power switch

* at least 4 I/O pins for SPI control of digital potentiometer

* 1 ADC for output voltage sensing

* 5V output to power other ICs would be nice

'''minimum requirements:''' 17 I/O pins, 1 ADC

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

[https://www.digikey.com/short/pcfvjt Similar DC/DC converter] with isolation but without adjustable output or display: ~$80

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1000 height=500></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN] and 50 kOhm resistor, or [https://www.digikey.com/short/pcqbwv IC DGTL POT 100K SPI 16-TSSOP] and 2 x 16kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====User Interface=====
Microcontroller: [https://www.digikey.com/short/pcf1cb IC MCU 32BIT 64KB FLASH 44LGA] ($4, highest resolution ADC) or [https://www.digikey.com/short/pcf1tq IC MCU 32BIT 128KB FLASH 64LQFP] ($6, similar specs to Arduino Mega)
LCD: [https://www.digikey.com/short/pcfdpd LCD 4.5 DIGIT .4" TRANSFL]

BJTs: [https://www.digikey.com/short/pcfdp9 IC PWR RELAY N-CHAN U-DFN3030-10]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

=Bill of Materials=
==Buck/Boost Converter Module==
<html><iframe src="https://docs.google.com/spreadsheets/d/e/2PACX-1vRuPxZK24d7GdTwqzsNq4B9LgWyOsCs7YT73sC7Tw-9Zj6UBEbbaalxfD7FPRa9jBx9acQkj_Dh0Ln1/pubhtml?widget=true&headers=false" height=500 width=900></iframe></html>

[https://docs.google.com/spreadsheets/d/17jSD9Ku_RUkiSY8j9lGMdcOUFeJdl2H1anW0THEKH-g/edit?usp=sharing edit]

Adjustable Power Supply v18.08

2018-12-27T21:48:48Z

Mransaw: /* Voltage Conversion */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement SPI to control [https://www.digikey.com/short/pcqbwv digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?).

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- design PCB
- research microcontroller options for voltage control and display

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

===Microcontroller===
* ~11 I/O pins for 7-segment display

* 2 I/o pins for rotary encoder and power switch

* at least 4 I/O pins for SPI control of digital potentiometer

* 1 ADC for output voltage sensing

* 5V output to power other ICs would be nice

'''minimum requirements:''' 17 I/O pins, 1 ADC

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

[https://www.digikey.com/short/pcfvjt Similar DC/DC converter] with isolation but without adjustable output or display: ~$80

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1000 height=500></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN] and 50 kOhm resistor, or [https://www.digikey.com/short/pcqbwv IC DGTL POT 100K SPI 16-TSSOP] and 2 x 16kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====User Interface=====
BJTs: [https://www.digikey.com/short/pcfdp9 IC PWR RELAY N-CHAN U-DFN3030-10]

LCD: [https://www.digikey.com/short/pcfdpd LCD 4.5 DIGIT .4" TRANSFL]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

=Bill of Materials=
==Buck/Boost Converter Module==
<html><iframe src="https://docs.google.com/spreadsheets/d/e/2PACX-1vRuPxZK24d7GdTwqzsNq4B9LgWyOsCs7YT73sC7Tw-9Zj6UBEbbaalxfD7FPRa9jBx9acQkj_Dh0Ln1/pubhtml?widget=true&headers=false" height=500 width=900></iframe></html>

[https://docs.google.com/spreadsheets/d/17jSD9Ku_RUkiSY8j9lGMdcOUFeJdl2H1anW0THEKH-g/edit?usp=sharing edit]

Adjustable Power Supply v18.08

2018-12-27T21:44:53Z

Mransaw: /* Voltage Conversion */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement SPI to control [https://www.digikey.com/short/pcqbwv digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?).

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- design PCB
- research microcontroller options for voltage control and display

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

===Microcontroller===
* ~11 I/O pins for 7-segment display

* 2 I/o pins for rotary encoder and power switch

* at least 4 I/O pins for SPI control of digital potentiometer

* 1 ADC for output voltage sensing

* 5V output to power other ICs would be nice

'''minimum requirements:''' 17 I/O pins, 1 ADC

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

[https://www.digikey.com/short/pcfvjt Similar DC/DC converter] without adjustable output or display: ~$80

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1000 height=500></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN] and 50 kOhm resistor, or [https://www.digikey.com/short/pcqbwv IC DGTL POT 100K SPI 16-TSSOP] and 2 x 16kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====User Interface=====
BJTs: [https://www.digikey.com/short/pcfdp9 IC PWR RELAY N-CHAN U-DFN3030-10]

LCD: [https://www.digikey.com/short/pcfdpd LCD 4.5 DIGIT .4" TRANSFL]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

=Bill of Materials=
==Buck/Boost Converter Module==
<html><iframe src="https://docs.google.com/spreadsheets/d/e/2PACX-1vRuPxZK24d7GdTwqzsNq4B9LgWyOsCs7YT73sC7Tw-9Zj6UBEbbaalxfD7FPRa9jBx9acQkj_Dh0Ln1/pubhtml?widget=true&headers=false" height=500 width=900></iframe></html>

[https://docs.google.com/spreadsheets/d/17jSD9Ku_RUkiSY8j9lGMdcOUFeJdl2H1anW0THEKH-g/edit?usp=sharing edit]

Adjustable Power Supply v18.08

2018-12-27T20:32:59Z

Mransaw: /* User Interface */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement SPI to control [https://www.digikey.com/short/pcqbwv digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?).

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- design PCB
- research microcontroller options for voltage control and display

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

===Microcontroller===
* ~11 I/O pins for 7-segment display

* 2 I/o pins for rotary encoder and power switch

* at least 4 I/O pins for SPI control of digital potentiometer

* 1 ADC for output voltage sensing

* 5V output to power other ICs would be nice

'''minimum requirements:''' 17 I/O pins, 1 ADC

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1000 height=500></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN] and 50 kOhm resistor, or [https://www.digikey.com/short/pcqbwv IC DGTL POT 100K SPI 16-TSSOP] and 2 x 16kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====User Interface=====
BJTs: [https://www.digikey.com/short/pcfdp9 IC PWR RELAY N-CHAN U-DFN3030-10]

LCD: [https://www.digikey.com/short/pcfdpd LCD 4.5 DIGIT .4" TRANSFL]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

=Bill of Materials=
==Buck/Boost Converter Module==
<html><iframe src="https://docs.google.com/spreadsheets/d/e/2PACX-1vRuPxZK24d7GdTwqzsNq4B9LgWyOsCs7YT73sC7Tw-9Zj6UBEbbaalxfD7FPRa9jBx9acQkj_Dh0Ln1/pubhtml?widget=true&headers=false" height=500 width=900></iframe></html>

[https://docs.google.com/spreadsheets/d/17jSD9Ku_RUkiSY8j9lGMdcOUFeJdl2H1anW0THEKH-g/edit?usp=sharing edit]

Adjustable Power Supply v18.08

2018-12-27T19:03:11Z

Mransaw: /* Buck-Boost Converter */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement SPI to control [https://www.digikey.com/short/pcqbwv digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?).

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- design PCB
- research microcontroller options for voltage control and display

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

===Microcontroller===
* ~11 I/O pins for 7-segment display

* 2 I/o pins for rotary encoder and power switch

* at least 4 I/O pins for SPI control of digital potentiometer

* 1 ADC for output voltage sensing

* 5V output to power other ICs would be nice

'''minimum requirements:''' 17 I/O pins, 1 ADC

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1000 height=500></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN] and 50 kOhm resistor, or [https://www.digikey.com/short/pcqbwv IC DGTL POT 100K SPI 16-TSSOP] and 2 x 16kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====User Interface=====
BJTs: [https://www.digikey.com/short/pcf2vw TRANS 3NPN DARL 100V 4A 8-SIP]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

=Bill of Materials=
==Buck/Boost Converter Module==
<html><iframe src="https://docs.google.com/spreadsheets/d/e/2PACX-1vRuPxZK24d7GdTwqzsNq4B9LgWyOsCs7YT73sC7Tw-9Zj6UBEbbaalxfD7FPRa9jBx9acQkj_Dh0Ln1/pubhtml?widget=true&headers=false" height=500 width=900></iframe></html>

[https://docs.google.com/spreadsheets/d/17jSD9Ku_RUkiSY8j9lGMdcOUFeJdl2H1anW0THEKH-g/edit?usp=sharing edit]

Adjustable Power Supply v18.08

2018-12-27T19:02:45Z

Mransaw: /* Possible Parts */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement SPI to control [https://www.digikey.com/short/pcqbwv digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?).

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- design PCB
- research microcontroller options for voltage control and display

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

===Microcontroller===
* ~11 I/O pins for 7-segment display

* 2 I/o pins for rotary encoder and power switch

* at least 4 I/O pins for SPI control of digital potentiometer

* 1 ADC for output voltage sensing

* 5V output to power other ICs would be nice

'''minimum requirements:''' 17 I/O pins, 1 ADC

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1000 height=500></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN] and 50 kOhm resistor, or [https://www.digikey.com/short/pcqbwv IC DGTL POT 100K SPI 16-TSSOP] and 2 x 16kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====User Interface=====
BJTs: [https://www.digikey.com/short/pcf2vw TRANS 3NPN DARL 100V 4A 8-SIP]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

=Bill of Materials=
==Buck/Boost Converter Module==
<html><iframe src="https://docs.google.com/spreadsheets/d/e/2PACX-1vRuPxZK24d7GdTwqzsNq4B9LgWyOsCs7YT73sC7Tw-9Zj6UBEbbaalxfD7FPRa9jBx9acQkj_Dh0Ln1/pubhtml?widget=true&headers=false" height=500 width=900></iframe></html>

[https://docs.google.com/spreadsheets/d/17jSD9Ku_RUkiSY8j9lGMdcOUFeJdl2H1anW0THEKH-g/edit?usp=sharing edit]

Adjustable Power Supply v18.08

2018-12-27T18:57:49Z

Mransaw: /* Microcontroller */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement SPI to control [https://www.digikey.com/short/pcqbwv digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?).

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- design PCB
- research microcontroller options for voltage control and display

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

===Microcontroller===
* ~11 I/O pins for 7-segment display

* 2 I/o pins for rotary encoder and power switch

* at least 4 I/O pins for SPI control of digital potentiometer

* 1 ADC for output voltage sensing

* 5V output to power other ICs would be nice

'''minimum requirements:''' 17 I/O pins, 1 ADC

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1000 height=500></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN] and 50 kOhm resistor, or [https://www.digikey.com/short/pcqbwv IC DGTL POT 100K SPI 16-TSSOP] and 2 x 16kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

=Bill of Materials=
==Buck/Boost Converter Module==
<html><iframe src="https://docs.google.com/spreadsheets/d/e/2PACX-1vRuPxZK24d7GdTwqzsNq4B9LgWyOsCs7YT73sC7Tw-9Zj6UBEbbaalxfD7FPRa9jBx9acQkj_Dh0Ln1/pubhtml?widget=true&headers=false" height=500 width=900></iframe></html>

[https://docs.google.com/spreadsheets/d/17jSD9Ku_RUkiSY8j9lGMdcOUFeJdl2H1anW0THEKH-g/edit?usp=sharing edit]

Adjustable Power Supply v18.08

2018-12-27T18:55:08Z

Mransaw: /* Microcontroller */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement SPI to control [https://www.digikey.com/short/pcqbwv digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?).

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- design PCB
- research microcontroller options for voltage control and display

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

===Microcontroller===
~11 I/O pins for 7-segment display

2 I/o pins for rotary encoder and power switch

at least 4 I/O pins for SPI control of digital potentiometer

1 ADC for output voltage sensing

5V output to power other ICs would be nice

minimum requirements: 17 I/O pins, 1 ADC

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1000 height=500></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN] and 50 kOhm resistor, or [https://www.digikey.com/short/pcqbwv IC DGTL POT 100K SPI 16-TSSOP] and 2 x 16kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

=Bill of Materials=
==Buck/Boost Converter Module==
<html><iframe src="https://docs.google.com/spreadsheets/d/e/2PACX-1vRuPxZK24d7GdTwqzsNq4B9LgWyOsCs7YT73sC7Tw-9Zj6UBEbbaalxfD7FPRa9jBx9acQkj_Dh0Ln1/pubhtml?widget=true&headers=false" height=500 width=900></iframe></html>

[https://docs.google.com/spreadsheets/d/17jSD9Ku_RUkiSY8j9lGMdcOUFeJdl2H1anW0THEKH-g/edit?usp=sharing edit]

Adjustable Power Supply v18.08

2018-12-27T18:24:10Z

Mransaw: /* Requirements */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement SPI to control [https://www.digikey.com/short/pcqbwv digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?).

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- design PCB
- research microcontroller options for voltage control and display

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

===Microcontroller===
~11 I/O pins for 7-segment display

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1000 height=500></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN] and 50 kOhm resistor, or [https://www.digikey.com/short/pcqbwv IC DGTL POT 100K SPI 16-TSSOP] and 2 x 16kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

=Bill of Materials=
==Buck/Boost Converter Module==
<html><iframe src="https://docs.google.com/spreadsheets/d/e/2PACX-1vRuPxZK24d7GdTwqzsNq4B9LgWyOsCs7YT73sC7Tw-9Zj6UBEbbaalxfD7FPRa9jBx9acQkj_Dh0Ln1/pubhtml?widget=true&headers=false" height=500 width=900></iframe></html>

[https://docs.google.com/spreadsheets/d/17jSD9Ku_RUkiSY8j9lGMdcOUFeJdl2H1anW0THEKH-g/edit?usp=sharing edit]

Miles Log

2018-12-27T00:43:40Z

Mransaw:

<html><iframe width="600" height="300" src="https://osedev.org/wiki/Miles?start=3/1/2018"></iframe></html>

{{RightTOC}}
=Wed Dec 26, 2018=
Simplified [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck-Boost_Converter buck/boost converter design] and made [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck.2FBoost_Converter_Module bill of materials]

=Sun Dec 16, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#General Learning about 555 Timers and PWM]

=Mon Nov 19, 2018=
Learning about PWM and [https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator astable multivibrators]

=Sun Nov 11, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck-Boost_Converter Added control wiring to buck-boost converter draft design]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Calculations Studying voltage follower circuits to increase input impedance of ADC]

=Sun Nov 4, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck-Boost_Converter Working on buck-boost converter draft design]

=Fri Oct 26, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck-Boost_Converter_2 component selection for buck-boost converter]

=Mon Oct 1, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck-Boost_Converter Started draft design of 1.5kW buck-boost converter]

=Sun Sep 30, 2018=
Found [http://kicad.rohrbacher.net/quicklib.php KiCad symbol generator] and made [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Conceptual_Design symbol for PWM controller]

Learning how to implement [http://rohmfs.rohm.com/en/products/databook/datasheet/ic/power/switching_regulator/bd9850fvm-e.pdf PWM controller IC]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Design_buck.2Fboost_converter_circuit.2Fmodule Brainstorming ways to increase PWM frequency]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Calculations Doing calculations for buck-boost converter]

=Wed Sep 26, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Voltage_Conversion Researched buck-boost topologies]

=Tue Sep 25, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#General Researched Isolation in Digital Power Supplies]

=Mon Sep 24, 2018=
Circuit diagram and cost estimate for [https://wiki.opensourceecology.org/wiki/Current_Meeting current meeting]

Added possible parts to [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Forward_Configuration forward configuration]

=Sun Sep 23, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Figure_out_ways_to_salvage_or_build_transformers Reassessed flyback configuration] and [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Research organized research section]

=Sat Sep 22, 2018=
[http://www.ti.com/lit/ds/symlink/ucc28780.pdf learning about active flyback controller IC] and [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration_2 component selection]

=Wed Sep 19, 2018=
[http://www.ti.com/lit/ds/symlink/ucc28780.pdf learning how to use active clamp flyback controller IC]

=Mon Sep 17, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Research learning about gate drivers] and estimated cost of power supply components to be around $70 for the flyback configuration, not including the microcontroller and display

=Fri Sep 14, 2018=
Learning about active snubbers, [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration_2 found an IC to control them]

=Wed Sep 12, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Research Learning about lossless snubber circuits]

=Tue Sep 11, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration_2 selected some parts for flyback configuration of power supply]

found possible toroid powder core for flyback transformer

=Sun Sep 9, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration selected a possible core for flyback transformer]

=Sat Sep 8, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Transformer Learning about Flyback Transformer Design]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration Selected some possible parts for prototype]

=Wed Sep 5, 2018=
learning about buck-boost converters, [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Research flyback transformer design], and [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Possible_Parts component selection]

=Tue Sep 4, 2018=
[https://wiki.opensourceecology.org/wiki/Qucs#Running_the_Above_Simulation:_More_Details How to install Qucs-S]

=Sun Sep 2, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Figure_out_ways_to_salvage_or_build_transformers Learned about buck-boost converters and new possibilities for flyback transformers enabled by advancements in MOSFET technology]

=Wed Aug 29, 2018=
[http://www.ti.com/lit/an/slva059a/slva059a.pdf Learned about buck-boost power stages]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#To_Do.2FIn_Progress Made to do/in progress list]

=Tue Aug 28, 2018=
Talked with Jesse to brainstorm and plan next steps

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Software Created Git repository for microcontroller code]

=Mon Aug 27, 2018=
Learning about [https://www.academia.edu/36721604/RepRapable_Recyclebot_Open_source_3-D_printable_extruder_for_converting_plastic_to_3-D_printing_filament RecycleBot] and [https://en.wikipedia.org/wiki/PID_controller PID controllers]

=Sat Aug 25, 2018=
[https://wiki.opensourceecology.org/wiki/Qucs Made wiki page for Qucs]

Quc-S Simulation: {{YoutubePopup|SQkO3aYBCuk}}

=Thu Aug 23, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08 Adjustable Power Supply]

[https://www.digikey.com/short/jfnv75 Transformer], [https://www.digikey.com/short/jfnvtc Rectifier]

=Tue Aug 21, 2018=
[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08#Isolated Started BoM for Isolated Arduino Power Supply]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08#Prototyping Prototyped Non-isolated Arduino Power Supply, successfully produced 10V @ 380mA from 120Vac]

=Mon Aug 20, 2018=
<html><iframe src="https://docs.google.com/presentation/d/e/2PACX-1vTx4K6wvVdWwHGxGWjYOPPy4fUNDUj6HDOviTvzn8LSUzpZ5vf0IsRBg8UQxb4jbNPNayP32iX5rRdz/embed?start=false&loop=false&delayms=3000" frameborder="0" width="960" height="569" allowfullscreen="true" mozallowfullscreen="true" webkitallowfullscreen="true"></iframe></html>

[https://docs.google.com/presentation/d/1Y1zsd6oYwKa1JdSXy3bzswW5YfVC6J6c6HS8PW8RtUk/edit?usp=sharing ^edit^]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08#QUCS-S_Simulation Arduino Power Supply Simulation]

=Sat Aug 18, 2018=
[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08#Calculations Calculations for Arduino Power Supply]

=Fri Aug 17, 2018=
[https://wiki.opensourceecology.org/index.php?title=Arduino_Power_Supply_v18.08 Arduino Power Supply]

=Thu Aug 16, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Bill_of_Materials#BoM_for_Non-isolated_9V_Power_Supply_.28280_mA.29 BoM for Arduino power supply and voltage reference circuit]

=Wed Aug 15, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Qucs-s_Simulations Simulated non-isolated power supply for Arduino Mega]

=Tue Aug 14, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Qucs-s_Simulations Creating simulation of non-isolated power supply for Arduino Mega]

R&D for power supply to Arduino: [[Universal_Power_Supply/Bill_of_Materials#BoM_for_20W_Power_Supply_.2Fw_12_DC_Output]]

=Sun 12, 2018=
[http://ngspice.sourceforge.net/docs/ngspice-manual.pdf Learning about OpenMP with Ngspice for multi-core circuit simulation]

Updated [https://drive.google.com/drive/folders/15Kk7HLIvO4MyOILj4dJSY45LwgANmcUd?usp=sharing Power Supply Simulation].

Learning how to enable [https://sourceforge.net/p/ngspice/mailman/message/32611983/ multi-core processing to speed up simulation time].

=Sat Aug 11, 2018=
Installed [https://ra3xdh.github.io/ Qucs-s (Qucs with Spice)] to do transient analysis of circuits

=Fri Aug 10, 2018=
[https://drive.google.com/drive/folders/1jgUGcGJyVH43yN_hhrippUOOm9ozlwb5?usp=sharing Learning Qucs to Simulate Power Supply]

=Wed Aug 8, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Initial_Design Initial Design of 800W Power Supply]

=Tue Aug 7, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Bill_of_Materials#BoM_for_800W_Power_Supply_.2Fw_12-24V_DC_Output Bill of Materials for 800W Power Supply]

=Fri Aug 3, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Possible_Parts Possible Parts for UPS]

=Wed Aug 1, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Power_Supply_R.26D Power Supply R&D]

=Tue Jul 31, 2018=
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing Universal Power Supply (UPS) Block Diagram]

Notes at [[Miles Work Meeting]]

=Fri Jul 27, 2018=
[https://drive.google.com/file/d/1UHHGPRdyM7k2f22uKXJk5aKurP5DX-7o/view?usp=sharing FreeCAD Test File]

{{YoutubePopup|kCk6uS-fRUY}}
OSE Developer Test Video

How many hours each part of the test took to complete:

1) Installing Linux: ~3h. Tried to do a full install onto USB stick but display wouldn't work.

2) Learning FreeCAD: 4h

3) Documenting your work: 2h

Learning FreeCAD was the most difficult task.

Other feedback: A sample FreeCAD file with a competed cube would be helpful as a reference.

Score: 100% of test points completed.

=Wed Jul 18, 2018=
[https://youtu.be/aDrMAVgLg8g Video cover letter for OSE Development Team]

=Mon Jul 16, 2018=
[https://drive.google.com/file/d/1vIKdj6wP_aisvoNAvM7GocePa6G3KLck/view?usp=sharing Video Cover Letter Prep]

Installed [[OSE Linux]] on USB stick.

=Sun Jul 15, 2018=
Requested account but didn't receive confirmation email, communicated with [[Marcin]] to get it working. [https://drive.google.com/file/d/1KmuKzSFBM1K2_-l8ISi56kYi1zcYRf6x/view?usp=drivesdk]

Adjustable Power Supply v18.08

2018-12-27T00:41:34Z

Mransaw: /* Arduino code for voltage sensing and control */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement SPI to control [https://www.digikey.com/short/pcqbwv digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?).

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- design PCB
- research microcontroller options for voltage control and display

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1000 height=500></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN] and 50 kOhm resistor, or [https://www.digikey.com/short/pcqbwv IC DGTL POT 100K SPI 16-TSSOP] and 2 x 16kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

=Bill of Materials=
==Buck/Boost Converter Module==
<html><iframe src="https://docs.google.com/spreadsheets/d/e/2PACX-1vRuPxZK24d7GdTwqzsNq4B9LgWyOsCs7YT73sC7Tw-9Zj6UBEbbaalxfD7FPRa9jBx9acQkj_Dh0Ln1/pubhtml?widget=true&headers=false" height=500 width=900></iframe></html>

[https://docs.google.com/spreadsheets/d/17jSD9Ku_RUkiSY8j9lGMdcOUFeJdl2H1anW0THEKH-g/edit?usp=sharing edit]

Adjustable Power Supply v18.08

2018-12-27T00:41:11Z

Mransaw: /* Arduino code for voltage sensing and control */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement I2C to control [https://www.digikey.com/short/pcqbwv digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?).

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- design PCB
- research microcontroller options for voltage control and display

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1000 height=500></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN] and 50 kOhm resistor, or [https://www.digikey.com/short/pcqbwv IC DGTL POT 100K SPI 16-TSSOP] and 2 x 16kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

=Bill of Materials=
==Buck/Boost Converter Module==
<html><iframe src="https://docs.google.com/spreadsheets/d/e/2PACX-1vRuPxZK24d7GdTwqzsNq4B9LgWyOsCs7YT73sC7Tw-9Zj6UBEbbaalxfD7FPRa9jBx9acQkj_Dh0Ln1/pubhtml?widget=true&headers=false" height=500 width=900></iframe></html>

[https://docs.google.com/spreadsheets/d/17jSD9Ku_RUkiSY8j9lGMdcOUFeJdl2H1anW0THEKH-g/edit?usp=sharing edit]

Adjustable Power Supply v18.08

2018-12-27T00:40:28Z

Mransaw: /* Design buck/boost converter module */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement I2C to control [https://www.digikey.com/short/jvt11q digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?).

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- design PCB
- research microcontroller options for voltage control and display

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1000 height=500></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN] and 50 kOhm resistor, or [https://www.digikey.com/short/pcqbwv IC DGTL POT 100K SPI 16-TSSOP] and 2 x 16kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

=Bill of Materials=
==Buck/Boost Converter Module==
<html><iframe src="https://docs.google.com/spreadsheets/d/e/2PACX-1vRuPxZK24d7GdTwqzsNq4B9LgWyOsCs7YT73sC7Tw-9Zj6UBEbbaalxfD7FPRa9jBx9acQkj_Dh0Ln1/pubhtml?widget=true&headers=false" height=500 width=900></iframe></html>

[https://docs.google.com/spreadsheets/d/17jSD9Ku_RUkiSY8j9lGMdcOUFeJdl2H1anW0THEKH-g/edit?usp=sharing edit]

Adjustable Power Supply v18.08

2018-12-27T00:36:41Z

Mransaw: /* Buck-Boost Converter */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement I2C to control [https://www.digikey.com/short/jvt11q digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?). It may be possible to use a [https://www.digikey.com/short/jnjh98 high-frequency buck-boost controller IC] to handle the PWM, and control it with the Arduino via a [https://www.digikey.com/short/jnjhb8 digital potentiometer].

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- figure out how to switch between buck and boost configuration or simplify configuration
- make bill of materials for prototyping

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1000 height=500></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN] and 50 kOhm resistor, or [https://www.digikey.com/short/pcqbwv IC DGTL POT 100K SPI 16-TSSOP] and 2 x 16kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

=Bill of Materials=
==Buck/Boost Converter Module==
<html><iframe src="https://docs.google.com/spreadsheets/d/e/2PACX-1vRuPxZK24d7GdTwqzsNq4B9LgWyOsCs7YT73sC7Tw-9Zj6UBEbbaalxfD7FPRa9jBx9acQkj_Dh0Ln1/pubhtml?widget=true&headers=false" height=500 width=900></iframe></html>

[https://docs.google.com/spreadsheets/d/17jSD9Ku_RUkiSY8j9lGMdcOUFeJdl2H1anW0THEKH-g/edit?usp=sharing edit]

Adjustable Power Supply v18.08

2018-12-27T00:34:45Z

Mransaw: /* Bill of Materials */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement I2C to control [https://www.digikey.com/short/jvt11q digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?). It may be possible to use a [https://www.digikey.com/short/jnjh98 high-frequency buck-boost controller IC] to handle the PWM, and control it with the Arduino via a [https://www.digikey.com/short/jnjhb8 digital potentiometer].

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- figure out how to switch between buck and boost configuration or simplify configuration
- make bill of materials for prototyping

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1150 height=450></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN] and 50 kOhm resistor, or [https://www.digikey.com/short/pcqbwv IC DGTL POT 100K SPI 16-TSSOP] and 2 x 16kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

=Bill of Materials=
==Buck/Boost Converter Module==
<html><iframe src="https://docs.google.com/spreadsheets/d/e/2PACX-1vRuPxZK24d7GdTwqzsNq4B9LgWyOsCs7YT73sC7Tw-9Zj6UBEbbaalxfD7FPRa9jBx9acQkj_Dh0Ln1/pubhtml?widget=true&headers=false" height=500 width=900></iframe></html>

[https://docs.google.com/spreadsheets/d/17jSD9Ku_RUkiSY8j9lGMdcOUFeJdl2H1anW0THEKH-g/edit?usp=sharing edit]

Adjustable Power Supply v18.08

2018-12-27T00:34:14Z

Mransaw:

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement I2C to control [https://www.digikey.com/short/jvt11q digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?). It may be possible to use a [https://www.digikey.com/short/jnjh98 high-frequency buck-boost controller IC] to handle the PWM, and control it with the Arduino via a [https://www.digikey.com/short/jnjhb8 digital potentiometer].

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- figure out how to switch between buck and boost configuration or simplify configuration
- make bill of materials for prototyping

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1150 height=450></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN] and 50 kOhm resistor, or [https://www.digikey.com/short/pcqbwv IC DGTL POT 100K SPI 16-TSSOP] and 2 x 16kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

=Bill of Materials=
<html><iframe src="https://docs.google.com/spreadsheets/d/e/2PACX-1vRuPxZK24d7GdTwqzsNq4B9LgWyOsCs7YT73sC7Tw-9Zj6UBEbbaalxfD7FPRa9jBx9acQkj_Dh0Ln1/pubhtml?widget=true&headers=false" height=500 width=900></iframe></html>

[https://docs.google.com/spreadsheets/d/17jSD9Ku_RUkiSY8j9lGMdcOUFeJdl2H1anW0THEKH-g/edit?usp=sharing edit]

File:BuckBoostSch.jpg

2018-12-27T00:10:00Z

Mransaw: Mransaw uploaded a new version of File:BuckBoostSch.jpg

File:BuckBoostSch.jpg

2018-12-27T00:04:01Z

Mransaw: Mransaw uploaded a new version of File:BuckBoostSch.jpg

Adjustable Power Supply v18.08

2018-12-24T05:52:59Z

Mransaw: /* Main Circuit */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement I2C to control [https://www.digikey.com/short/jvt11q digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?). It may be possible to use a [https://www.digikey.com/short/jnjh98 high-frequency buck-boost controller IC] to handle the PWM, and control it with the Arduino via a [https://www.digikey.com/short/jnjhb8 digital potentiometer].

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- figure out how to switch between buck and boost configuration or simplify configuration
- make bill of materials for prototyping

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1150 height=450></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN] and 50 kOhm resistor, or [https://www.digikey.com/short/pcqbwv IC DGTL POT 100K SPI 16-TSSOP] and 2 x 16kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

Adjustable Power Supply v18.08

2018-12-17T16:19:38Z

Mransaw: /* Buck-Boost Converter */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement I2C to control [https://www.digikey.com/short/jvt11q digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?). It may be possible to use a [https://www.digikey.com/short/jnjh98 high-frequency buck-boost controller IC] to handle the PWM, and control it with the Arduino via a [https://www.digikey.com/short/jnjhb8 digital potentiometer].

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- figure out how to switch between buck and boost configuration or simplify configuration
- make bill of materials for prototyping

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1150 height=450></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN] and 50 kOhm resistor, or [https://www.digikey.com/short/pcqbwv IC DGTL POT 100K SPI 16-TSSOP]

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

Miles Log

2018-12-17T00:58:21Z

Mransaw:

<html><iframe width="600" height="300" src="https://osedev.org/wiki/Miles?start=3/1/2018"></iframe></html>

{{RightTOC}}
=Sun Dec 16, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#General Learning about 555 Timers and PWM]

=Mon Nov 19, 2018=
Learning about PWM and [https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator astable multivibrators]

=Sun Nov 11, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck-Boost_Converter Added control wiring to buck-boost converter draft design]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Calculations Studying voltage follower circuits to increase input impedance of ADC]

=Sun Nov 4, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck-Boost_Converter Working on buck-boost converter draft design]

=Fri Oct 26, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck-Boost_Converter_2 component selection for buck-boost converter]

=Mon Oct 1, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck-Boost_Converter Started draft design of 1.5kW buck-boost converter]

=Sun Sep 30, 2018=
Found [http://kicad.rohrbacher.net/quicklib.php KiCad symbol generator] and made [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Conceptual_Design symbol for PWM controller]

Learning how to implement [http://rohmfs.rohm.com/en/products/databook/datasheet/ic/power/switching_regulator/bd9850fvm-e.pdf PWM controller IC]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Design_buck.2Fboost_converter_circuit.2Fmodule Brainstorming ways to increase PWM frequency]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Calculations Doing calculations for buck-boost converter]

=Wed Sep 26, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Voltage_Conversion Researched buck-boost topologies]

=Tue Sep 25, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#General Researched Isolation in Digital Power Supplies]

=Mon Sep 24, 2018=
Circuit diagram and cost estimate for [https://wiki.opensourceecology.org/wiki/Current_Meeting current meeting]

Added possible parts to [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Forward_Configuration forward configuration]

=Sun Sep 23, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Figure_out_ways_to_salvage_or_build_transformers Reassessed flyback configuration] and [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Research organized research section]

=Sat Sep 22, 2018=
[http://www.ti.com/lit/ds/symlink/ucc28780.pdf learning about active flyback controller IC] and [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration_2 component selection]

=Wed Sep 19, 2018=
[http://www.ti.com/lit/ds/symlink/ucc28780.pdf learning how to use active clamp flyback controller IC]

=Mon Sep 17, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Research learning about gate drivers] and estimated cost of power supply components to be around $70 for the flyback configuration, not including the microcontroller and display

=Fri Sep 14, 2018=
Learning about active snubbers, [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration_2 found an IC to control them]

=Wed Sep 12, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Research Learning about lossless snubber circuits]

=Tue Sep 11, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration_2 selected some parts for flyback configuration of power supply]

found possible toroid powder core for flyback transformer

=Sun Sep 9, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration selected a possible core for flyback transformer]

=Sat Sep 8, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Transformer Learning about Flyback Transformer Design]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration Selected some possible parts for prototype]

=Wed Sep 5, 2018=
learning about buck-boost converters, [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Research flyback transformer design], and [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Possible_Parts component selection]

=Tue Sep 4, 2018=
[https://wiki.opensourceecology.org/wiki/Qucs#Running_the_Above_Simulation:_More_Details How to install Qucs-S]

=Sun Sep 2, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Figure_out_ways_to_salvage_or_build_transformers Learned about buck-boost converters and new possibilities for flyback transformers enabled by advancements in MOSFET technology]

=Wed Aug 29, 2018=
[http://www.ti.com/lit/an/slva059a/slva059a.pdf Learned about buck-boost power stages]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#To_Do.2FIn_Progress Made to do/in progress list]

=Tue Aug 28, 2018=
Talked with Jesse to brainstorm and plan next steps

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Software Created Git repository for microcontroller code]

=Mon Aug 27, 2018=
Learning about [https://www.academia.edu/36721604/RepRapable_Recyclebot_Open_source_3-D_printable_extruder_for_converting_plastic_to_3-D_printing_filament RecycleBot] and [https://en.wikipedia.org/wiki/PID_controller PID controllers]

=Sat Aug 25, 2018=
[https://wiki.opensourceecology.org/wiki/Qucs Made wiki page for Qucs]

Quc-S Simulation: {{YoutubePopup|SQkO3aYBCuk}}

=Thu Aug 23, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08 Adjustable Power Supply]

[https://www.digikey.com/short/jfnv75 Transformer], [https://www.digikey.com/short/jfnvtc Rectifier]

=Tue Aug 21, 2018=
[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08#Isolated Started BoM for Isolated Arduino Power Supply]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08#Prototyping Prototyped Non-isolated Arduino Power Supply, successfully produced 10V @ 380mA from 120Vac]

=Mon Aug 20, 2018=
<html><iframe src="https://docs.google.com/presentation/d/e/2PACX-1vTx4K6wvVdWwHGxGWjYOPPy4fUNDUj6HDOviTvzn8LSUzpZ5vf0IsRBg8UQxb4jbNPNayP32iX5rRdz/embed?start=false&loop=false&delayms=3000" frameborder="0" width="960" height="569" allowfullscreen="true" mozallowfullscreen="true" webkitallowfullscreen="true"></iframe></html>

[https://docs.google.com/presentation/d/1Y1zsd6oYwKa1JdSXy3bzswW5YfVC6J6c6HS8PW8RtUk/edit?usp=sharing ^edit^]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08#QUCS-S_Simulation Arduino Power Supply Simulation]

=Sat Aug 18, 2018=
[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08#Calculations Calculations for Arduino Power Supply]

=Fri Aug 17, 2018=
[https://wiki.opensourceecology.org/index.php?title=Arduino_Power_Supply_v18.08 Arduino Power Supply]

=Thu Aug 16, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Bill_of_Materials#BoM_for_Non-isolated_9V_Power_Supply_.28280_mA.29 BoM for Arduino power supply and voltage reference circuit]

=Wed Aug 15, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Qucs-s_Simulations Simulated non-isolated power supply for Arduino Mega]

=Tue Aug 14, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Qucs-s_Simulations Creating simulation of non-isolated power supply for Arduino Mega]

R&D for power supply to Arduino: [[Universal_Power_Supply/Bill_of_Materials#BoM_for_20W_Power_Supply_.2Fw_12_DC_Output]]

=Sun 12, 2018=
[http://ngspice.sourceforge.net/docs/ngspice-manual.pdf Learning about OpenMP with Ngspice for multi-core circuit simulation]

Updated [https://drive.google.com/drive/folders/15Kk7HLIvO4MyOILj4dJSY45LwgANmcUd?usp=sharing Power Supply Simulation].

Learning how to enable [https://sourceforge.net/p/ngspice/mailman/message/32611983/ multi-core processing to speed up simulation time].

=Sat Aug 11, 2018=
Installed [https://ra3xdh.github.io/ Qucs-s (Qucs with Spice)] to do transient analysis of circuits

=Fri Aug 10, 2018=
[https://drive.google.com/drive/folders/1jgUGcGJyVH43yN_hhrippUOOm9ozlwb5?usp=sharing Learning Qucs to Simulate Power Supply]

=Wed Aug 8, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Initial_Design Initial Design of 800W Power Supply]

=Tue Aug 7, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Bill_of_Materials#BoM_for_800W_Power_Supply_.2Fw_12-24V_DC_Output Bill of Materials for 800W Power Supply]

=Fri Aug 3, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Possible_Parts Possible Parts for UPS]

=Wed Aug 1, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Power_Supply_R.26D Power Supply R&D]

=Tue Jul 31, 2018=
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing Universal Power Supply (UPS) Block Diagram]

Notes at [[Miles Work Meeting]]

=Fri Jul 27, 2018=
[https://drive.google.com/file/d/1UHHGPRdyM7k2f22uKXJk5aKurP5DX-7o/view?usp=sharing FreeCAD Test File]

{{YoutubePopup|kCk6uS-fRUY}}
OSE Developer Test Video

How many hours each part of the test took to complete:

1) Installing Linux: ~3h. Tried to do a full install onto USB stick but display wouldn't work.

2) Learning FreeCAD: 4h

3) Documenting your work: 2h

Learning FreeCAD was the most difficult task.

Other feedback: A sample FreeCAD file with a competed cube would be helpful as a reference.

Score: 100% of test points completed.

=Wed Jul 18, 2018=
[https://youtu.be/aDrMAVgLg8g Video cover letter for OSE Development Team]

=Mon Jul 16, 2018=
[https://drive.google.com/file/d/1vIKdj6wP_aisvoNAvM7GocePa6G3KLck/view?usp=sharing Video Cover Letter Prep]

Installed [[OSE Linux]] on USB stick.

=Sun Jul 15, 2018=
Requested account but didn't receive confirmation email, communicated with [[Marcin]] to get it working. [https://drive.google.com/file/d/1KmuKzSFBM1K2_-l8ISi56kYi1zcYRf6x/view?usp=drivesdk]

Adjustable Power Supply v18.08

2018-12-17T00:35:28Z

Mransaw: /* General */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement I2C to control [https://www.digikey.com/short/jvt11q digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?). It may be possible to use a [https://www.digikey.com/short/jnjh98 high-frequency buck-boost controller IC] to handle the PWM, and control it with the Arduino via a [https://www.digikey.com/short/jnjhb8 digital potentiometer].

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- figure out how to switch between buck and boost configuration or simplify configuration
- make bill of materials for prototyping

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://youtu.be/i0SNb__dkYI How a 555 Timer works]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1150 height=450></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN], 50 kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

Adjustable Power Supply v18.08

2018-12-17T00:32:33Z

Mransaw: /* General */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement I2C to control [https://www.digikey.com/short/jvt11q digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?). It may be possible to use a [https://www.digikey.com/short/jnjh98 high-frequency buck-boost controller IC] to handle the PWM, and control it with the Arduino via a [https://www.digikey.com/short/jnjhb8 digital potentiometer].

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- figure out how to switch between buck and boost configuration or simplify configuration
- make bill of materials for prototyping

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://howtomechatronics.com/how-it-works/electronics/how-to-make-pwm-dc-motor-speed-controller-using-555-timer-ic/ 555 Timer for PWM]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1150 height=450></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN], 50 kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

Adjustable Power Supply v18.08

2018-12-17T00:26:38Z

Mransaw: /* Main Circuit */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement I2C to control [https://www.digikey.com/short/jvt11q digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?). It may be possible to use a [https://www.digikey.com/short/jnjh98 high-frequency buck-boost controller IC] to handle the PWM, and control it with the Arduino via a [https://www.digikey.com/short/jnjhb8 digital potentiometer].

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- figure out how to switch between buck and boost configuration or simplify configuration
- make bill of materials for prototyping

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1150 height=450></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B] or [https://www.digikey.com/short/pc3rrv IC REG CTRLR BUCK-BOOST 20QFN] or 555 Timer

555 Timer: [https://www.digikey.com/short/pc3r5z IC OSC SINGLE TIMER 3MHZ 8-SOIC]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN], 50 kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

Miles Log

2018-12-10T19:01:06Z

Mransaw:

<html><iframe width="600" height="300" src="https://osedev.org/wiki/Miles?start=3/1/2018"></iframe></html>

{{RightTOC}}
=Mon Nov 19, 2018=
Learning about PWM and [https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator astable multivibrators]

=Sun Nov 11, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck-Boost_Converter Added control wiring to buck-boost converter draft design]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Calculations Studying voltage follower circuits to increase input impedance of ADC]

=Sun Nov 4, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck-Boost_Converter Working on buck-boost converter draft design]

=Fri Oct 26, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck-Boost_Converter_2 component selection for buck-boost converter]

=Mon Oct 1, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck-Boost_Converter Started draft design of 1.5kW buck-boost converter]

=Sun Sep 30, 2018=
Found [http://kicad.rohrbacher.net/quicklib.php KiCad symbol generator] and made [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Conceptual_Design symbol for PWM controller]

Learning how to implement [http://rohmfs.rohm.com/en/products/databook/datasheet/ic/power/switching_regulator/bd9850fvm-e.pdf PWM controller IC]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Design_buck.2Fboost_converter_circuit.2Fmodule Brainstorming ways to increase PWM frequency]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Calculations Doing calculations for buck-boost converter]

=Wed Sep 26, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Voltage_Conversion Researched buck-boost topologies]

=Tue Sep 25, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#General Researched Isolation in Digital Power Supplies]

=Mon Sep 24, 2018=
Circuit diagram and cost estimate for [https://wiki.opensourceecology.org/wiki/Current_Meeting current meeting]

Added possible parts to [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Forward_Configuration forward configuration]

=Sun Sep 23, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Figure_out_ways_to_salvage_or_build_transformers Reassessed flyback configuration] and [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Research organized research section]

=Sat Sep 22, 2018=
[http://www.ti.com/lit/ds/symlink/ucc28780.pdf learning about active flyback controller IC] and [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration_2 component selection]

=Wed Sep 19, 2018=
[http://www.ti.com/lit/ds/symlink/ucc28780.pdf learning how to use active clamp flyback controller IC]

=Mon Sep 17, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Research learning about gate drivers] and estimated cost of power supply components to be around $70 for the flyback configuration, not including the microcontroller and display

=Fri Sep 14, 2018=
Learning about active snubbers, [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration_2 found an IC to control them]

=Wed Sep 12, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Research Learning about lossless snubber circuits]

=Tue Sep 11, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration_2 selected some parts for flyback configuration of power supply]

found possible toroid powder core for flyback transformer

=Sun Sep 9, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration selected a possible core for flyback transformer]

=Sat Sep 8, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Transformer Learning about Flyback Transformer Design]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration Selected some possible parts for prototype]

=Wed Sep 5, 2018=
learning about buck-boost converters, [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Research flyback transformer design], and [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Possible_Parts component selection]

=Tue Sep 4, 2018=
[https://wiki.opensourceecology.org/wiki/Qucs#Running_the_Above_Simulation:_More_Details How to install Qucs-S]

=Sun Sep 2, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Figure_out_ways_to_salvage_or_build_transformers Learned about buck-boost converters and new possibilities for flyback transformers enabled by advancements in MOSFET technology]

=Wed Aug 29, 2018=
[http://www.ti.com/lit/an/slva059a/slva059a.pdf Learned about buck-boost power stages]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#To_Do.2FIn_Progress Made to do/in progress list]

=Tue Aug 28, 2018=
Talked with Jesse to brainstorm and plan next steps

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Software Created Git repository for microcontroller code]

=Mon Aug 27, 2018=
Learning about [https://www.academia.edu/36721604/RepRapable_Recyclebot_Open_source_3-D_printable_extruder_for_converting_plastic_to_3-D_printing_filament RecycleBot] and [https://en.wikipedia.org/wiki/PID_controller PID controllers]

=Sat Aug 25, 2018=
[https://wiki.opensourceecology.org/wiki/Qucs Made wiki page for Qucs]

Quc-S Simulation: {{YoutubePopup|SQkO3aYBCuk}}

=Thu Aug 23, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08 Adjustable Power Supply]

[https://www.digikey.com/short/jfnv75 Transformer], [https://www.digikey.com/short/jfnvtc Rectifier]

=Tue Aug 21, 2018=
[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08#Isolated Started BoM for Isolated Arduino Power Supply]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08#Prototyping Prototyped Non-isolated Arduino Power Supply, successfully produced 10V @ 380mA from 120Vac]

=Mon Aug 20, 2018=
<html><iframe src="https://docs.google.com/presentation/d/e/2PACX-1vTx4K6wvVdWwHGxGWjYOPPy4fUNDUj6HDOviTvzn8LSUzpZ5vf0IsRBg8UQxb4jbNPNayP32iX5rRdz/embed?start=false&loop=false&delayms=3000" frameborder="0" width="960" height="569" allowfullscreen="true" mozallowfullscreen="true" webkitallowfullscreen="true"></iframe></html>

[https://docs.google.com/presentation/d/1Y1zsd6oYwKa1JdSXy3bzswW5YfVC6J6c6HS8PW8RtUk/edit?usp=sharing ^edit^]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08#QUCS-S_Simulation Arduino Power Supply Simulation]

=Sat Aug 18, 2018=
[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08#Calculations Calculations for Arduino Power Supply]

=Fri Aug 17, 2018=
[https://wiki.opensourceecology.org/index.php?title=Arduino_Power_Supply_v18.08 Arduino Power Supply]

=Thu Aug 16, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Bill_of_Materials#BoM_for_Non-isolated_9V_Power_Supply_.28280_mA.29 BoM for Arduino power supply and voltage reference circuit]

=Wed Aug 15, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Qucs-s_Simulations Simulated non-isolated power supply for Arduino Mega]

=Tue Aug 14, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Qucs-s_Simulations Creating simulation of non-isolated power supply for Arduino Mega]

R&D for power supply to Arduino: [[Universal_Power_Supply/Bill_of_Materials#BoM_for_20W_Power_Supply_.2Fw_12_DC_Output]]

=Sun 12, 2018=
[http://ngspice.sourceforge.net/docs/ngspice-manual.pdf Learning about OpenMP with Ngspice for multi-core circuit simulation]

Updated [https://drive.google.com/drive/folders/15Kk7HLIvO4MyOILj4dJSY45LwgANmcUd?usp=sharing Power Supply Simulation].

Learning how to enable [https://sourceforge.net/p/ngspice/mailman/message/32611983/ multi-core processing to speed up simulation time].

=Sat Aug 11, 2018=
Installed [https://ra3xdh.github.io/ Qucs-s (Qucs with Spice)] to do transient analysis of circuits

=Fri Aug 10, 2018=
[https://drive.google.com/drive/folders/1jgUGcGJyVH43yN_hhrippUOOm9ozlwb5?usp=sharing Learning Qucs to Simulate Power Supply]

=Wed Aug 8, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Initial_Design Initial Design of 800W Power Supply]

=Tue Aug 7, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Bill_of_Materials#BoM_for_800W_Power_Supply_.2Fw_12-24V_DC_Output Bill of Materials for 800W Power Supply]

=Fri Aug 3, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Possible_Parts Possible Parts for UPS]

=Wed Aug 1, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Power_Supply_R.26D Power Supply R&D]

=Tue Jul 31, 2018=
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing Universal Power Supply (UPS) Block Diagram]

Notes at [[Miles Work Meeting]]

=Fri Jul 27, 2018=
[https://drive.google.com/file/d/1UHHGPRdyM7k2f22uKXJk5aKurP5DX-7o/view?usp=sharing FreeCAD Test File]

{{YoutubePopup|kCk6uS-fRUY}}
OSE Developer Test Video

How many hours each part of the test took to complete:

1) Installing Linux: ~3h. Tried to do a full install onto USB stick but display wouldn't work.

2) Learning FreeCAD: 4h

3) Documenting your work: 2h

Learning FreeCAD was the most difficult task.

Other feedback: A sample FreeCAD file with a competed cube would be helpful as a reference.

Score: 100% of test points completed.

=Wed Jul 18, 2018=
[https://youtu.be/aDrMAVgLg8g Video cover letter for OSE Development Team]

=Mon Jul 16, 2018=
[https://drive.google.com/file/d/1vIKdj6wP_aisvoNAvM7GocePa6G3KLck/view?usp=sharing Video Cover Letter Prep]

Installed [[OSE Linux]] on USB stick.

=Sun Jul 15, 2018=
Requested account but didn't receive confirmation email, communicated with [[Marcin]] to get it working. [https://drive.google.com/file/d/1KmuKzSFBM1K2_-l8ISi56kYi1zcYRf6x/view?usp=drivesdk]

Adjustable Power Supply v18.08

2018-11-26T16:44:14Z

Mransaw: /* Design buck/boost converter module */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement I2C to control [https://www.digikey.com/short/jvt11q digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?). It may be possible to use a [https://www.digikey.com/short/jnjh98 high-frequency buck-boost controller IC] to handle the PWM, and control it with the Arduino via a [https://www.digikey.com/short/jnjhb8 digital potentiometer].

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- figure out how to switch between buck and boost configuration or simplify configuration
- make bill of materials for prototyping

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1150 height=450></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Cost of components: ~$35

Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN], 50 kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

Miles Log

2018-11-20T06:42:17Z

Mransaw:

Adjustable Power Supply v18.08

2018-11-20T06:41:19Z

Mransaw: /* Voltage Conversion */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement I2C to control [https://www.digikey.com/short/jvt11q digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?). It may be possible to use a [https://www.digikey.com/short/jnjh98 high-frequency buck-boost controller IC] to handle the PWM, and control it with the Arduino via a [https://www.digikey.com/short/jnjhb8 digital potentiometer].

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- figure out how to switch between buck and boost configuration
- make bill of materials for prototyping

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Multivibrator#Astable_multivibrator Astable multivibrator]

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1150 height=450></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Cost of components: ~$35

Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN], 50 kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

Adjustable Power Supply v18.08

2018-11-16T16:32:55Z

Mransaw: /* Design buck/boost converter module */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement I2C to control [https://www.digikey.com/short/jvt11q digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?). It may be possible to use a [https://www.digikey.com/short/jnjh98 high-frequency buck-boost controller IC] to handle the PWM, and control it with the Arduino via a [https://www.digikey.com/short/jnjhb8 digital potentiometer].

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- simulate main circuit
- figure out how to switch between buck and boost configuration
- make bill of materials for prototyping

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1150 height=450></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Cost of components: ~$35

Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN], 50 kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

Adjustable Power Supply v18.08

2018-11-14T07:01:22Z

Mransaw: /* Flyback Configuration */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement I2C to control [https://www.digikey.com/short/jvt11q digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?). It may be possible to use a [https://www.digikey.com/short/jnjh98 high-frequency buck-boost controller IC] to handle the PWM, and control it with the Arduino via a [https://www.digikey.com/short/jnjhb8 digital potentiometer].

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- figure out how to switch between buck and boost configuration
- make bill of materials for prototyping

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1150 height=450></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing edit]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Cost of components: ~$35

Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN], 50 kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

Adjustable Power Supply v18.08

2018-11-14T07:00:18Z

Mransaw: /* Design buck/boost converter circuit/module */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement I2C to control [https://www.digikey.com/short/jvt11q digital potentiometer]

==Design buck/boost converter module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?). It may be possible to use a [https://www.digikey.com/short/jnjh98 high-frequency buck-boost controller IC] to handle the PWM, and control it with the Arduino via a [https://www.digikey.com/short/jnjhb8 digital potentiometer].

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- figure out how to switch between buck and boost configuration
- make bill of materials for prototyping

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1150 height=450></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing [edit]]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Cost of components: ~$35

Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN], 50 kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

Adjustable Power Supply v18.08

2018-11-14T07:00:02Z

Mransaw: /* Arduino PWM code and voltage sensing */

=In Progress=
==Arduino code for voltage sensing and control==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement I2C to control [https://www.digikey.com/short/jvt11q digital potentiometer]

==Design buck/boost converter circuit/module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?). It may be possible to use a [https://www.digikey.com/short/jnjh98 high-frequency buck-boost controller IC] to handle the PWM, and control it with the Arduino via a [https://www.digikey.com/short/jnjhb8 digital potentiometer].

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- figure out how to switch between buck and boost configuration
- make bill of materials for prototyping

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1150 height=450></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing [edit]]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Cost of components: ~$35

Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN], 50 kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

File:BuckBoostSch.jpg

2018-11-13T00:03:13Z

Mransaw: Mransaw uploaded a new version of File:BuckBoostSch.jpg

Adjustable Power Supply v18.08

2018-11-13T00:00:02Z

Mransaw: /* Design buck/boost converter circuit/module */

=In Progress=
==Arduino PWM code and voltage sensing==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement I2C to control [https://www.digikey.com/short/jvt11q digital potentiometer]

==Design buck/boost converter circuit/module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?). It may be possible to use a [https://www.digikey.com/short/jnjh98 high-frequency buck-boost controller IC] to handle the PWM, and control it with the Arduino via a [https://www.digikey.com/short/jnjhb8 digital potentiometer].

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- figure out how to switch between buck and boost configuration
- make bill of materials for prototyping

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1150 height=450></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing [edit]]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Cost of components: ~$35

Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN], 50 kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

Adjustable Power Supply v18.08

2018-11-12T20:46:03Z

Mransaw: /* Design buck/boost converter circuit/module */

=In Progress=
==Arduino PWM code and voltage sensing==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement I2C to control [https://www.digikey.com/short/jvt11q digital potentiometer]

==Design buck/boost converter circuit/module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?). It may be possible to use a [https://www.digikey.com/short/jnjh98 high-frequency buck-boost controller IC] to handle the PWM, and control it with the Arduino via a [https://www.digikey.com/short/jnjhb8 digital potentiometer].

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- figure out how to switch between buck and boost configuration

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1150 height=450></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing [edit]]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Cost of components: ~$35

Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN], 50 kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

Adjustable Power Supply v18.08

2018-11-12T20:42:05Z

Mransaw: /* In Progress */

=In Progress=
==Arduino PWM code and voltage sensing==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

Next steps:
- implement I2C to control [https://www.digikey.com/short/jvt11q digital potentiometer]

==Design buck/boost converter circuit/module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?). It may be possible to use a [https://www.digikey.com/short/jnjh98 high-frequency buck-boost controller IC] to handle the PWM, and control it with the Arduino via a [https://www.digikey.com/short/jnjhb8 digital potentiometer].

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- add isolation between power and control
- figure out how to switch between buck and boost configuration
- add voltage followers to IC inputs that are connected to voltage dividers

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1150 height=450></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing [edit]]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Cost of components: ~$35

Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN], 50 kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

Adjustable Power Supply v18.08

2018-11-12T20:34:21Z

Mransaw: /* Voltage Sensing */

=In Progress=
==Arduino PWM code and voltage sensing==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

==Design buck/boost converter circuit/module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?). It may be possible to use a [https://www.digikey.com/short/jnjh98 high-frequency buck-boost controller IC] to handle the PWM, and control it with the Arduino via a [https://www.digikey.com/short/jnjhb8 digital potentiometer].

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- learn how to control digital potentiometer
- add voltage sensing
- add isolation between power and control
- figure out how to switch between buck and boost configuration
- add voltage followers to IC inputs that are connected to voltage dividers

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1150 height=450></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing [edit]]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Cost of components: ~$35

Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN], 50 kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jvt1rm RES SMD 442K OHM 1% 1/16W 0402], [https://www.digikey.ca/short/jvt1rw RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

Adjustable Power Supply v18.08

2018-11-12T20:17:48Z

Mransaw: /* Buck-Boost Converter */

=In Progress=
==Arduino PWM code and voltage sensing==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

==Design buck/boost converter circuit/module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?). It may be possible to use a [https://www.digikey.com/short/jnjh98 high-frequency buck-boost controller IC] to handle the PWM, and control it with the Arduino via a [https://www.digikey.com/short/jnjhb8 digital potentiometer].

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- learn how to control digital potentiometer
- add voltage sensing
- add isolation between power and control
- figure out how to switch between buck and boost configuration
- add voltage followers to IC inputs that are connected to voltage dividers

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1150 height=450></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing [edit]]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Cost of components: ~$35

Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN], 50 kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

=====Voltage Sensing=====
Voltage divider: [https://www.digikey.ca/short/jv7nn7 RES SMD 402K OHM 0.5% 1/10W 0805], [https://www.digikey.ca/short/jv7nnm RES SMD 4.99M OHM 1% 1/16W 0402]

Op amp for voltage buffer: [https://www.digikey.com/short/jvt1cd IC OPAMP GP 1MHZ RRO SOT23-5]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

Miles Log

2018-11-12T06:13:55Z

Mransaw:

<html><iframe width="600" height="300" src="https://osedev.org/wiki/Miles?start=3/1/2018"></iframe></html>

{{RightTOC}}
=Sun Nov 11, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck-Boost_Converter Added control wiring to buck-boost converter draft design]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Calculations Studying voltage follower circuits to increase input impedance of ADC]

=Sun Nov 4, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck-Boost_Converter Working on buck-boost converter draft design]

=Fri Oct 26, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck-Boost_Converter_2 component selection for buck-boost converter]

=Mon Oct 1, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Buck-Boost_Converter Started draft design of 1.5kW buck-boost converter]

=Sun Sep 30, 2018=
Found [http://kicad.rohrbacher.net/quicklib.php KiCad symbol generator] and made [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Conceptual_Design symbol for PWM controller]

Learning how to implement [http://rohmfs.rohm.com/en/products/databook/datasheet/ic/power/switching_regulator/bd9850fvm-e.pdf PWM controller IC]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Design_buck.2Fboost_converter_circuit.2Fmodule Brainstorming ways to increase PWM frequency]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Calculations Doing calculations for buck-boost converter]

=Wed Sep 26, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Voltage_Conversion Researched buck-boost topologies]

=Tue Sep 25, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#General Researched Isolation in Digital Power Supplies]

=Mon Sep 24, 2018=
Circuit diagram and cost estimate for [https://wiki.opensourceecology.org/wiki/Current_Meeting current meeting]

Added possible parts to [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Forward_Configuration forward configuration]

=Sun Sep 23, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Figure_out_ways_to_salvage_or_build_transformers Reassessed flyback configuration] and [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Research organized research section]

=Sat Sep 22, 2018=
[http://www.ti.com/lit/ds/symlink/ucc28780.pdf learning about active flyback controller IC] and [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration_2 component selection]

=Wed Sep 19, 2018=
[http://www.ti.com/lit/ds/symlink/ucc28780.pdf learning how to use active clamp flyback controller IC]

=Mon Sep 17, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Research learning about gate drivers] and estimated cost of power supply components to be around $70 for the flyback configuration, not including the microcontroller and display

=Fri Sep 14, 2018=
Learning about active snubbers, [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration_2 found an IC to control them]

=Wed Sep 12, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Research Learning about lossless snubber circuits]

=Tue Sep 11, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration_2 selected some parts for flyback configuration of power supply]

found possible toroid powder core for flyback transformer

=Sun Sep 9, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration selected a possible core for flyback transformer]

=Sat Sep 8, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Transformer Learning about Flyback Transformer Design]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Flyback_Configuration Selected some possible parts for prototype]

=Wed Sep 5, 2018=
learning about buck-boost converters, [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Research flyback transformer design], and [https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Possible_Parts component selection]

=Tue Sep 4, 2018=
[https://wiki.opensourceecology.org/wiki/Qucs#Running_the_Above_Simulation:_More_Details How to install Qucs-S]

=Sun Sep 2, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Figure_out_ways_to_salvage_or_build_transformers Learned about buck-boost converters and new possibilities for flyback transformers enabled by advancements in MOSFET technology]

=Wed Aug 29, 2018=
[http://www.ti.com/lit/an/slva059a/slva059a.pdf Learned about buck-boost power stages]

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#To_Do.2FIn_Progress Made to do/in progress list]

=Tue Aug 28, 2018=
Talked with Jesse to brainstorm and plan next steps

[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08#Software Created Git repository for microcontroller code]

=Mon Aug 27, 2018=
Learning about [https://www.academia.edu/36721604/RepRapable_Recyclebot_Open_source_3-D_printable_extruder_for_converting_plastic_to_3-D_printing_filament RecycleBot] and [https://en.wikipedia.org/wiki/PID_controller PID controllers]

=Sat Aug 25, 2018=
[https://wiki.opensourceecology.org/wiki/Qucs Made wiki page for Qucs]

Quc-S Simulation: {{YoutubePopup|SQkO3aYBCuk}}

=Thu Aug 23, 2018=
[https://wiki.opensourceecology.org/wiki/Adjustable_Power_Supply_v18.08 Adjustable Power Supply]

[https://www.digikey.com/short/jfnv75 Transformer], [https://www.digikey.com/short/jfnvtc Rectifier]

=Tue Aug 21, 2018=
[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08#Isolated Started BoM for Isolated Arduino Power Supply]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08#Prototyping Prototyped Non-isolated Arduino Power Supply, successfully produced 10V @ 380mA from 120Vac]

=Mon Aug 20, 2018=
<html><iframe src="https://docs.google.com/presentation/d/e/2PACX-1vTx4K6wvVdWwHGxGWjYOPPy4fUNDUj6HDOviTvzn8LSUzpZ5vf0IsRBg8UQxb4jbNPNayP32iX5rRdz/embed?start=false&loop=false&delayms=3000" frameborder="0" width="960" height="569" allowfullscreen="true" mozallowfullscreen="true" webkitallowfullscreen="true"></iframe></html>

[https://docs.google.com/presentation/d/1Y1zsd6oYwKa1JdSXy3bzswW5YfVC6J6c6HS8PW8RtUk/edit?usp=sharing ^edit^]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08#QUCS-S_Simulation Arduino Power Supply Simulation]

=Sat Aug 18, 2018=
[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08#Calculations Calculations for Arduino Power Supply]

=Fri Aug 17, 2018=
[https://wiki.opensourceecology.org/index.php?title=Arduino_Power_Supply_v18.08 Arduino Power Supply]

=Thu Aug 16, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Bill_of_Materials#BoM_for_Non-isolated_9V_Power_Supply_.28280_mA.29 BoM for Arduino power supply and voltage reference circuit]

=Wed Aug 15, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Qucs-s_Simulations Simulated non-isolated power supply for Arduino Mega]

=Tue Aug 14, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Qucs-s_Simulations Creating simulation of non-isolated power supply for Arduino Mega]

R&D for power supply to Arduino: [[Universal_Power_Supply/Bill_of_Materials#BoM_for_20W_Power_Supply_.2Fw_12_DC_Output]]

=Sun 12, 2018=
[http://ngspice.sourceforge.net/docs/ngspice-manual.pdf Learning about OpenMP with Ngspice for multi-core circuit simulation]

Updated [https://drive.google.com/drive/folders/15Kk7HLIvO4MyOILj4dJSY45LwgANmcUd?usp=sharing Power Supply Simulation].

Learning how to enable [https://sourceforge.net/p/ngspice/mailman/message/32611983/ multi-core processing to speed up simulation time].

=Sat Aug 11, 2018=
Installed [https://ra3xdh.github.io/ Qucs-s (Qucs with Spice)] to do transient analysis of circuits

=Fri Aug 10, 2018=
[https://drive.google.com/drive/folders/1jgUGcGJyVH43yN_hhrippUOOm9ozlwb5?usp=sharing Learning Qucs to Simulate Power Supply]

=Wed Aug 8, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Initial_Design Initial Design of 800W Power Supply]

=Tue Aug 7, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Bill_of_Materials#BoM_for_800W_Power_Supply_.2Fw_12-24V_DC_Output Bill of Materials for 800W Power Supply]

=Fri Aug 3, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Possible_Parts Possible Parts for UPS]

=Wed Aug 1, 2018=
[https://wiki.opensourceecology.org/wiki/Universal_Power_Supply/Research_Development#Power_Supply_R.26D Power Supply R&D]

=Tue Jul 31, 2018=
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing Universal Power Supply (UPS) Block Diagram]

Notes at [[Miles Work Meeting]]

=Fri Jul 27, 2018=
[https://drive.google.com/file/d/1UHHGPRdyM7k2f22uKXJk5aKurP5DX-7o/view?usp=sharing FreeCAD Test File]

{{YoutubePopup|kCk6uS-fRUY}}
OSE Developer Test Video

How many hours each part of the test took to complete:

1) Installing Linux: ~3h. Tried to do a full install onto USB stick but display wouldn't work.

2) Learning FreeCAD: 4h

3) Documenting your work: 2h

Learning FreeCAD was the most difficult task.

Other feedback: A sample FreeCAD file with a competed cube would be helpful as a reference.

Score: 100% of test points completed.

=Wed Jul 18, 2018=
[https://youtu.be/aDrMAVgLg8g Video cover letter for OSE Development Team]

=Mon Jul 16, 2018=
[https://drive.google.com/file/d/1vIKdj6wP_aisvoNAvM7GocePa6G3KLck/view?usp=sharing Video Cover Letter Prep]

Installed [[OSE Linux]] on USB stick.

=Sun Jul 15, 2018=
Requested account but didn't receive confirmation email, communicated with [[Marcin]] to get it working.

Adjustable Power Supply v18.08

2018-11-12T06:11:13Z

Mransaw: /* Calculations */

=In Progress=
==Arduino PWM code and voltage sensing==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

==Design buck/boost converter circuit/module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?). It may be possible to use a [https://www.digikey.com/short/jnjh98 high-frequency buck-boost controller IC] to handle the PWM, and control it with the Arduino via a [https://www.digikey.com/short/jnjhb8 digital potentiometer].

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- learn how to control digital potentiometer
- add voltage sensing
- add isolation between power and control
- figure out how to switch between buck and boost configuration
- add voltage followers to IC inputs that are connected to voltage dividers

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><a href=https://wiki.opensourceecology.org/images/8/8a/BuckBoostCalc.jpeg>With only 30 kHz, a large and expensive inductor would be needed.</a></html>

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1150 height=450></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing [edit]]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Cost of components: ~$35

Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN], 50 kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

Voltage divider for sensing output: [https://www.digikey.ca/short/jv7nn7 RES SMD 402K OHM 0.5% 1/10W 0805], [https://www.digikey.ca/short/jv7nnm RES SMD 4.99M OHM 1% 1/16W 0402]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

Adjustable Power Supply v18.08

2018-11-12T05:52:24Z

Mransaw: /* Calculations */

=In Progress=
==Arduino PWM code and voltage sensing==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

==Design buck/boost converter circuit/module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?). It may be possible to use a [https://www.digikey.com/short/jnjh98 high-frequency buck-boost controller IC] to handle the PWM, and control it with the Arduino via a [https://www.digikey.com/short/jnjhb8 digital potentiometer].

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- learn how to control digital potentiometer
- add voltage sensing
- add isolation between power and control
- figure out how to switch between buck and boost configuration
- add voltage followers to IC inputs that are connected to voltage dividers

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><img src=https://wiki.opensourceecology.org/images/thumb/8/8a/BuckBoostCalc.jpeg/510px-BuckBoostCalc.jpeg></html>

With only 30 kHz, a large and expensive inductor would be needed.

[https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html Transistor biasing]

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1150 height=450></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing [edit]]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Cost of components: ~$35

Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN], 50 kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

Voltage divider for sensing output: [https://www.digikey.ca/short/jv7nn7 RES SMD 402K OHM 0.5% 1/10W 0805], [https://www.digikey.ca/short/jv7nnm RES SMD 4.99M OHM 1% 1/16W 0402]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

Adjustable Power Supply v18.08

2018-11-12T04:33:21Z

Mransaw: /* General */

=In Progress=
==Arduino PWM code and voltage sensing==

[https://bitbucket.org/telephoneman/ups_pwm/src/3e0b14a3d3ba677face0fc56dc1f67f8a1673296/arduinocode Arduino code is hosted here.] This code is far from finalized and represent only one of many possible design approaches. Post as many variations or improvements as you can as long as they have advantages.

==Design buck/boost converter circuit/module==
For affordable buck-boost that can change voltage by a factor of five, high frequencies are needed to reduce inductor size. The Arduino has a limited PWM frequency (less than 100 kHz?). It may be possible to use a [https://www.digikey.com/short/jnjh98 high-frequency buck-boost controller IC] to handle the PWM, and control it with the Arduino via a [https://www.digikey.com/short/jnjhb8 digital potentiometer].

Volt-second balance on the inductor means that the average voltage across it over one switching cycle is zero

Discontinuous mode is when current through the output inductor is zero for part of the switching cycle

Next steps:
- learn how to control digital potentiometer
- add voltage sensing
- add isolation between power and control
- figure out how to switch between buck and boost configuration
- add voltage followers to IC inputs that are connected to voltage dividers

==Figure out ways to salvage or build transformers==

Investigate ways to use high frequency for more efficiency in power transformation as well as smaller inductors.

With new Silicon Carbide MOSFET technology, maybe feasible to use flyback transformer at high frequency as described [https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf1200 here].

A flyback transformer could more compact and cheaper initially, but the lifetime cost of replacing a large input capacitor would likely outweigh the initial savings. It is also more complex than an AC transformer, so probably not the best choice for this application.

=Design=

==Applications==
Powering 3D printer

Workbench power supply

Charging batteries

==Requirements==
At least 360W output (12V at 30A)

Adjustable DC voltage output up to 24V

120Vac input

==Research==
===Existing Open-Source Projects===
[https://github.com/eez-open/psu-hw Programmable bench power supply EEZ H24005]

[https://hackaday.io/project/4154-bench-power-supply Bench Power Supply]

===General===
[https://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf Safety Considerations in Power Supply Design]

[https://en.wikipedia.org/wiki/Common_collector Common collector amplifiers] can be used as [https://en.wikipedia.org/wiki/Buffer_amplifier#Voltage_buffer voltage buffers]

[https://www.maximintegrated.com/en/app-notes/index.mvp/id/3081 How to Increase the Bandwidth of Digital Potentiometers 10x to 100x]

[https://www.allaboutcircuits.com/technical-articles/why-the-capacitor-in-your-power-supply-filter-is-too-big/ Ripple Port to Reduce Output Capacitor Size]

[http://www.analog.com/en/technical-articles/isolation-in-digital-power-supply-why-and-how.html Isolation in Digital Power Supply]

[http://www.ti.com/lit/ml/slua618/slua618.pdf Fundamentals of Gate Driver Circuits]

[http://iopscience.iop.org/article/10.1088/1742-6596/977/1/012007 Open-source based synthetic medium-voltage grid model for distribution power supply systems]

[https://www.st.com/content/ccc/resource/technical/document/application_note/a4/ef/bc/7d/78/89/49/f1/DM00098381.pdf/files/DM00098381.pdf/jcr:content/translations/en.DM00098381.pdf Current Sharing in Parallel Diodes]

===Voltage Conversion===
[http://www.learnabout-electronics.org/PSU/psu33.php This page] is a great guide.

[https://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter Buck–boost converter]

[http://www.ti.com/lit/an/slva059a/slva059a.pdf Understanding Buck-Boost Power Stages]

[https://www.mouser.de/pdfdocs/BuckConverterDesignNote.pdf Buck Converter Design]

===Flyback Transformer===
[https://www.electronicdesign.com/power/active-clamp-flyback-converter-design-whose-time-has-come The Active Clamp Flyback Converter: A Design Whose Time Has Come]

[https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7074&context=etd A Comparison of Different Snubbers for Flyback Converters]

[https://www.ti.com/lit/ml/slup127/slup127.pdf Inductor and Flyback Transformer Design]

[https://dspace.vutbr.cz/bitstream/handle/11012/43074/eeict2015-621-martis.pdf 1200 WATT FLYBACK SWITCHING POWER SUPPLY WITH SILICON CARBIDE SEMICONDUCTORS]

[http://eas.uccs.edu/~cwang/ECE5955_F2015/PowerElectronics_f2015/ch2/Sect2-2.pdf Inductor volt-second balance, capacitor charge balance, and the small ripple approximation]

[https://www.ti.com/seclit/ml/slup338/slup338.pdf Flyback transformer design considerations for efficiency and EMI]

[http://www.ee.bgu.ac.il/~pel/pdf-files/smnr13.pdf PASSIVE LOSSLESS SNUBBERS FOR HIGH FREQUENCY PWM CONVERTERS] (page 41)

==Modules==
<html><iframe src="https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/preview" width="800" height="300"></iframe></html>
[https://drive.google.com/file/d/14E6jdRYcacSnh8N1ed87tpt4PYiifUkv/view?usp=sharing edit]

[https://wiki.opensourceecology.org/wiki/Arduino_Power_Supply_v18.08 Arduino Power Subcircuit]

===Flyback Transformer===
A flyback transformer would most likely be operated in continuous conduction mode, so transformer size will be limited by core saturation. A toroid with powder core could be a suitable solution.

Switching speeds of MOSFET and diodes should be minimized to reduce switching losses. Winding losses should be minimized as well.

[https://www.mag-inc.com/Products/Selecting-a-Distributed-Air-Gap-Powder-Core-for-Fl Selecting a Distributed Air-Gap Powder Core for Flyback Transformers]

[https://micrometalsarnoldpowdercores.com/design-software Inductor Design Tool]

==Calculations==
<html><img src=https://wiki.opensourceecology.org/images/thumb/8/8a/BuckBoostCalc.jpeg/510px-BuckBoostCalc.jpeg></html>

With only 30 kHz, a large and expensive inductor would be needed.

[https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.ti.com/lit/an/slva721a/slva721a.pdf&ved=2ahUKEwjX3L_Nv-LdAhVLHzQIHViWBzcQFjABegQIBxAB&usg=AOvVaw1Rfq8vmjUTgXz3TBK5JtWO Buck-Boost Design Calculations]

[https://drive.google.com/file/d/160fBKhaJohxqErDVsghaS8F-OIE37cVb/view?usp=sharing Digital potentiometer calculations]

==Conceptual Design==
'''''These designs may not be safe or functional. Use at your own risk.'''''

[http://kicad.rohrbacher.net/quicklib.php KiCAD Symbol Generator], <html><a href=https://drive.google.com/file/d/1LtR22AovAHlzEcM65HuDW818-tB03zNA/view?usp=sharing>DB9851.lib</a>, <a href=https://drive.google.com/file/d/1uvr8XZ4-E1sGj2WWG3NTgnj2rY3qOkTe/view?usp=sharing>UC24612.lib</a></html>
===Buck-Boost Converter===
<html><a href=https://wiki.opensourceecology.org/wiki/File:BuckBoostSch.jpg><img src=https://wiki.opensourceecology.org/images/c/cf/BuckBoostSch.jpg width=1150 height=450></a><a href=https://drive.google.com/drive/folders/1GTlBO0V6huO2SHp2aWkBbo3RVD3Nfane?usp=sharing>edit</a></html>

===Flyback Configuration===
https://wiki.opensourceecology.org/images/thumb/f/fc/FlybackDraft.jpg/800px-FlybackDraft.jpg [https://drive.google.com/file/d/1dRuDUdYCjfiMH3gN5b1DNvURy5PTcsm4/view?usp=sharing [edit]]

'''DRAFT, values are not correct'''

10 gauge wire for secondary winding. Primary has 8.5 turns, try 3 or 3.5 for secondary.

==Software==
[https://bitbucket.org/OSEUPS/apsv1808/src/master/ Git Repository]

==Possible Parts==
Output Capacitor: Aluminum (cheaper but more lossy), organic semiconductor (good overall), tantalum (best for surface mount) [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Output Inductor: Bobbin or rod-core cause more noise [http://www.ti.com/lit/an/slva059a/slva059a.pdf]

Isolator: [https://www.digikey.ca/short/jw00p5 DGTL ISO 2.5KV 2CH GEN PURP 8DIP]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jnc47m SOT-23-5]

Digital Potentiometer: [https://www.digikey.com/short/jv7n34 IC DGTL POT 10BIT NV 14-TSSOP]

===Buck-Boost Converter===
=====Main Circuit=====
Cost of components: ~$35

Switching Transistors: [https://www.digikey.ca/short/jnjmwq MOSFET N-CH 60V 100A POWERDI5060] or [https://www.digikey.ca/short/jnjmwh MOSFET N-CH 60V 200A TO-220-3]

Inductor: [https://www.digikey.ca/short/jnjh8c FIXED IND 33UH 30A 1.9MOHM SMD] (would require 2.5 MHz switching frequency)

Rectifier Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

PWM Controller: [https://www.digikey.com/short/jnjwcd IC REG CTRLR BUCK/BST 20HTSSOP-B]

Digital Potentiometer: [https://www.digikey.com/short/j0rqqt IC DGTL POT 10BIT 16TQFN], 50 kOhm resistor

Input/Output Capacitor: [https://www.digikey.com/short/j075p3 CAP CER 15UF 100V X7S SMD]

=====PWM Control=====
High-side gate driver: [https://www.digikey.com/short/jv7b44 IC HIGH-SIDE DVR HS HV 8-MSOP]

Gate driver bootstrap diode: [https://www.digikey.com/short/jv75jm DIODE GEN PURP 100V 200MA SOD80]

Oscillation setting: [https://www.digikey.com/short/j0r7f0 CAP CER 47PF 50V C0G/NP0 0201], 4.7 kOhm resistor

Short circuit protection timer: [https://www.digikey.com/short/j0rtrj CAP CER 0.47UF 100V X7R 0805]

Error Amp Feedback: [https://www.digikey.com/short/j0rttm CAP CER 0.068UF 100V X7R 0805], 100 Ohm resistor

Voltage divider for sensing output: [https://www.digikey.ca/short/jv7nn7 RES SMD 402K OHM 0.5% 1/10W 0805], [https://www.digikey.ca/short/jv7nnm RES SMD 4.99M OHM 1% 1/16W 0402]

=====Control Circuit Power=====
Voltage regulator: [https://www.digikey.com/short/jv7558 IC REG BUCK 12V 1A TO220-5]

===Forward Configuration===
Transformer: [https://www.digikey.com/short/jfnv75 XFRMR TOROIDAL 500VA CHAS MOUNT],
[https://wiki.opensourceecology.org/wiki/Microwave_Transformer Investigating ways to salvage transformers]

Rectifier: [https://www.digikey.com/short/jfnvtc RECT BRIDGE FAST 3PHASE I4-PAC-5]

[https://pdf1.alldatasheet.com/datasheet-pdf/view/68504/IRF/IRFP250N.html IRFP250N]Power transistor (MOSFET) driven by [https://www.microchip.com/wwwproducts/en/en010647 TC1411] 1A High-Speed MOSFET Driver with pulse signal originating from arduino.

(Alternative mosfets requiring no mosfer driver)
[https://www.infineon.com/dgdl/irf540n.pdf?fileId=5546d462533600a4015355e396cb199f IRF540N "IR" MOSFET N-Channel 33A 100V]
[https://www.digchip.com/datasheets/parts/datasheet/161/IRFP250N-pdf.php IRFP250N]

Switching Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]

===Flyback Configuration===
Cost of components ~$80

Fuse: [https://www.digikey.com/short/jwncf2 FUSE GLASS 15A 250VAC 5X20MM]

Bridge Rectifier: [https://www.digikey.com/short/jw71qw 50A, 600V BRIDGE RECTIFIER, GBJ], [https://www.digikey.com/short/j2d0dw DIODE BRIDGE FAST DIODE ECO-PAC1], [https://www.digikey.com/short/j2rtq3 50A, 1000V BRIDGE RECTIFIER, GBJ]

Input Capacitor: [https://www.digikey.com/short/jw7vw0 CAP ALUM 18000UF 20% 160V SCREW]

====Snubber====
Snubber Diode: [https://www.digikey.com/short/jwt9dh DIODE SCHOTTKY 250V 40A TO220AB]

Snubber Capacitor: [https://www.digikey.com/short/jwzccj CAP CER 0.18UF 250V X7R 1812]

Active Snubber Control: [https://www.digikey.com/short/jwjj5m Active clamp flyback controller UCC28780D]

Gate Driver Transistors: [https://www.digikey.com/short/jwm5wn TRANS NPN 60V 3A TP], [https://www.digikey.com/short/jwm1d2 TRANS PNP 60V 5A TO-126]

Integrated Gate Driver: [https://www.digikey.com/short/jwhc5v IC DRIVER HI/LO SIDE 600V 14-DIP]

====Coupled Inductor====
Switching Transistor: [https://www.digikey.com/short/jw729f MOSFET NCH 650V 21A TO247N], [https://www.digikey.ca/short/j2mvd3 MOSFET NCH 650V 39A TO247N]

Transformer: [https://www.digikey.com/short/jwtcn5 FIXED IND 10UH 16.9A 5.1 MOHM TH], [https://www.mag-inc.com/Media/Magnetics/Datasheets/0077130A7.pdf Kool Mu 77130A7 (11.2mm outer diameter, permeability = 125 u)]

====Output Rectifier====
Output Diode: [https://www.digikey.com/short/j2dvjj DIODE SCHOTTKY 45V 60A TO247AD]

Synchronous Rectifier IC: [https://www.digikey.ca/short/jwnc78 SYNC RECTIFIER FLYBACK]

Synchronous Rectifier Transistor: [https://www.digikey.ca/short/jwnc84 MOSFET N-CH 40V 95A TO-220AB]