Problem Statement for a Universal Power Supply

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We're interested in a universal, modular power conversion device for electricity.

I am talking about different modules that can be plugged together for something like a Lego Set of power electronics. Each module would in itself be modular, so it can consist of a number of units connected for scaling current or voltage.

The modules could create:

  • 60 hz electricity at common voltage such as 110 or 220 or 440
  • DC current for plasma cutters or welders
  • Battery charge-controller current
  • High frequency power for induction furnaces
  • Regulation of variable voltage (say 60-220 v ac) to charge batteries
  • DC-DC conversion.

That just about covers all power devices for advanced civilization, more or less.

Anyway, the general scheme would be to: (1) rectify a typically oscilating input from some power generating device, if it's not DC already, (2) chop it up, (3) scale it, (4) form it, (5) and finally, spit it out as DC or AC.

Anyway, a thesis could be written on the above. We're interested in implementation. Our practical needs at Factor e Farm are:

1. Powering welders, plasma cutters, battery chargers, induction furnaces, CO2 laser cutters 2. Inverters for household power from batteries 3. Voltage regulation/conditioning to get grid-quality power from variable power sources such as windmills, steam engines (especially solar powered) 4. Battery charging from windmills, steam engines

Basically, we want to create a universal switched mode power supply kit, with some power conditioning and regulation.

Can you help on this? Are you interested in this?

If so, please propose a basic starting circuit to take any AC input (from an ac generator), and take it to either battery storage or an inverter/converter.

The first step would be to specify parts for a system that can run from 100W to about 20kW for starters. Is this feasible, or is the problem statement ill-defined?

We have not discussed 3 phase. Afer the above, we'd have to go to 3-phase converters, since many appliances of interest (such as induction furnaces) run off 3-phase.

So if the above is too much, let's start first by defining the problem statement clearly. For us, the problem statement is creating an open source power electronics toolkit for the world, relevant to any post-scarcity community. I'd like it to be modular, in that components can be plugged into the system readily (replacements) of power modules and brain modules alike. This would include plug-in of power-handling components with ready connection to heat sinks.


  • For the inverter function - scalability should occur on number of phases, voltage, current, and frequency scalability,
  • Stackability is a part of the inverter. See Stackable Inverter.

Systems Engineering Breakdown Diagram

  • See relevant projects - Induction Furnace, Universal Power Supply, Universal Welder, Plasma Cutter, Laser Cutter
  • Can we design a universal set of plug-and-play modules that address all of the above?
    • Start by defining and prototyping interconnection standards. Suggested: bolt-and-nut bus bar for power interconnect; screwdown terminal for logic connections
    • Also need to question the standard way of doing things and see if we can conform to a central standard (i.e. if an Induction furnace is now AC because of convention, does it always need to be?)
      • Staying in DC will always be easier if going from batteries, though standard devices might not be compatible.

Currently Available Machines

Machine name Low end power needs High end power needs AC or DC?
Mig Welder 2.4 kW 10 kW AC
Arc Welder DC or AC
Stick Welder AC
Plasma Torch 2 kW DC

Some of the rough estimations here were taken from the welding depot site.