Stepper Motor Controller
Introduction
http://en.wikipedia.org/wiki/Stepper_motor
This is a goldmine for drivers: http://reprap.org/wiki/StepperMotor#Stepper_drivers
Off-the-shelf options
- 5 axis version of controller brain (minus power handling) - can this be used with any power-handling system? - [1]
- An up to .75A brawn module from Sparkfun - [2]
- Any advantage cf. open source RepRap stepper controllers?
- This does offer USB connection, and is open source - [3]
- 3 axis, 3A kit on eBay, $200 - [4]
- CNC Stepper Motor Controller at [5].
Turnkey systems
- 2-axis, 4A, 24V system - [6]
Technical information
Education
Overview
- Overview of stepper motor and driver technology: http://www.ams2000.com/pdf/step101.pdf
- Good resource with links, explanations, and physics: http://www.cs.uiowa.edu/~jones/step/
Motor driver circuits
Must-read info on motor driving circuits. Basic [7], and current limiting [8].
Stepper motor sizes
- Nema 23 motors are about 6x6x8 cm size - and require _______ amps for driving.
- Xylotex says body length is 3"
Electromechanical operation
- Good diagrams here showing the inside of a stepper motor [9].
- Choose motor type and number of leads, and it generates an image of the motor [10]. Not in English.
- Stepper motor disassembled. http://www.ducttapeeng.com/smd/smd1.htm
Microstepping
http://www.zaber.com/wiki/Tutorials/Microstepping
Motor control lab
High-level architecture
Insert picture of overall architecture showing the control computer, the indexer, the power supply, and the driving circuit.
Indexer
Discuss indexer functionality and implementation.
Chopper circuit design
In this section we focus on what seems to be the most common modern design for stepper motor controllers, the chopper circuit. From Wikipedia:
"Modern stepper controllers drive the motor with much higher voltages than the motor nameplate rated voltage, and limit current through chopping. The usual setup is to have a positioning controller, known as an indexer, sending step and direction pulses to a separate higher voltage drive circuit which is responsible for commutation and current limiting"
Open source projects
RepRap 3D printer
http://reprap.org/wiki/StepperMotor
OSE design
Brainstorming
Power supply
What if we used power supply units from PCs? They're pretty high current and they can be placed in series for 12 volt, 24 volt, 36 volt, etc, systems. They've got 5 volt taps to run the microcontroller off of. They're ubiquitous and either free or cheap. Jason 00:46, 23 May 2011 (PDT)
Crazy idea - combine inverter and motor controller circuits onto one board
It seems to me that the high cost of both motor controllers and inverters are some pricy power electronics components. What if we could reuse those expensive power electronics components to make a single circuit that can either be an inverter or motor controller? An inverter takes DC power from batteries and creates an AC signal. However, when running motors, you don't need that functionality, because you're taking DC power and running motors with it. So, potentially, with a single expensive piece of power electronics, you could combine inverter and motor controlling capabilities for just a little more than supporting just a single function. Discuss. Jason 03:32, 23 May 2011 (PDT)
Vacuum tubes
http://openfarmtech.org/forum/discussion/220/making-vacuum-tubes
We have need of some power electronics, which include inverters and motor controllers. The primary cost of these circuits are the power electronic components. While we could definitely look at what it would take to make some of these semiconductor components, another option would be to look into what it would take to make vacuum tubes. This could potentially cut out those $20 mosfets we will need, and all the other components should be inexpensive in comparison. We aren't creating perfect audio here, or trying to make a communications system. We're simply powering stuff. Maybe its feasible. Jason 12:03, 23 May 2011 (PDT)