Yesterday evening I completed the first of the plug in modules that simply allows me switch the thing on and off, monitor the output voltages and fault conditions.

This is as basic a module as you can have, consisting of only LEDs and resistors. Later, I will create a better monitoring card that can actually monitor the output voltages. For now, I will rely on the PSUs own low-voltage signal.

These PC PSU’s need a decent load on their outputs for them to function correctly. After some research and experimentation I found that 50 ohms across the +12v did the trick and the output voltages remain steady and seem well regulated. One article I found suggested loading the +5v line as well, but this PSU really didn’t like that and refused to start.

Next step is to start designing some output cards. A simple card to start containing a switching regulator for +5v with several switched outputs and a couple of amps to begin with.

After this I really need a stable 0 to 10v fine adjustable output at around an amp. This will allow me to calibrate my data logger project