ATX PSU into Bench PSU

Posted by jiGGaK on September 24th, 2011
Bench-top power supply

I stumbled upon this video by Phil Levchenko showing how to turn an ATX power supply into a bench power supply. I had an old PSU laying around and thought this would be a perfect way to give it a new life. Phil’s video is great, but I found the video tutorial format a bit tricky to follow at times.

Click through for some pictures, tips and diagrams that you may find helpful.

Diagrams

Standard ATX wire colours
Schematic

Tips

Lots-o-wires

When I started tearing down the PSU I was tempted to start de-soldering all those extra red, yellow, orange, and black wires. Twisting them together and routing them to binding posts seemed like too much of a pain. Then I realized that these PSUs are capable of providing a pretty significant amount of current (~20 Amps on 5v rail)! The wires in my power supply are 18 AWG, and I couldn’t find a definitive answer to how much current a single wire could safely carry. So in the end I kept 6 wires per colour… just to be safe.

In my PSU I chose to pull out +12v, +5v, and +3.3v to binding posts since I can’t imagine a use for -12v or -5v.

One last glamour shot


jiGGaK September 24th, 2011

Hi Phil,

Don’t get me wrong, the video is great! The content is perfect for us electronics nerds out there. I think putting diagrams and a bill of materials on your site would make them that much more useful.

Thanks again for the project idea!

Phil September 24th, 2011

Hi!

You right, that it is hard to follow video tutorials. They’re cool for learning something, but then using it as instructions to do something could be pain in the rear. I’m gonna write small articles for my videos, just to provide material that was on video in readable form. I guess will do the same for some of the old videos.

About -12V. You could use it to get 24V (between +12V and -12V) - which can be very handy.