Make a variable desktop supply from an ATX power supply

Thread Starter


Joined Sep 29, 2017
I have a few ATX power supplies laying around and I see a lot of posts from people that have done this.
Most have not been variable and some have been pretty ugly.
Plus, I trust the folks here and wanted to see if anyone had made one recently, say within the last year.

George KG5TKY


Joined Aug 1, 2013
I don't like them because they are noisy and have restrictions. A common characteristic of most multi-output switching power supplies is that one output has a minimum load requirement, usually 10% of its max output current rating, before the rest of the outputs are stable. Also, changing an output voltage might cause the output to oscillate, especially if the design is the fixed reference/variable gain type (as opposed to the fixed gain/variable reference type).