A continuation of the ATX PSU conversion, I wanted to add a fully variable output and followed these notes to build a suitable circuit on breadboard for testing purposes:


The main component is the LM317T voltage regulator. Here is the trial circuit:



The pot is quite sensitive and I need to sort this out as it is difficult to control the voltage but it is stable once you get it there. This is the lowest voltage possible 1.26v


At 10.00V

At maximum – 19.81V. Really this should be 24v so I think I need to change the load resistor.

Again, this is just a log of what I am doing. These switch PSU are dangerous.