making a lab power supply

calvary3a1 · Post by **calvary3a1** » Tue Jun 20, 2006 8:14 pm

I have an old pc power supply and i want to make it into a lab power supply with 5v, 12v, and 3.3v. I have found some information on how to do this but I know it can be dangerous and none of the examples i have found are specific enough for me to feel safe doing it. Can someone show me Step-by-step instructions on how to do this. I mean i want every little step explained, prefferably with pictures. Also, if any of you have done this maybe you could show some pictures. Thanks

superdeformed · Post by **superdeformed** » Tue Jun 20, 2006 9:36 pm

I came across an old power supply the other day (buried under stuff in the basement of course) and was thinking of doing this too. A quick search brought up this site.

Post by **gannon** » Wed Jun 21, 2006 8:05 am

That's what I did in my older bench PSU, but I added in a few other voltage sources and a gcn LCD and a/v input.

calvary3a1 · Post by **calvary3a1** » Wed Jun 21, 2006 11:28 am

Thanks for the link. I started on those instructions but i have a few questions. first, is there any way to tell if the psu is discharged. I touched the red and black wires and nothing at all happened. I was expecting a spark but maybe im wrong. Second, I dont have all of the wires listed in that tutorial. I have red, black, 1 yellow, 1 white, and orange. Is it still possible to do it with that tutorial?

Joes2Silly · Post by **Joes2Silly** » Wed Jun 21, 2006 11:39 am

what exactly is a lab power supply used for anyway

calvary3a1 · Post by **calvary3a1** » Wed Jun 21, 2006 11:50 am

basically they give you multiple power outputs like 5v and 12v to use to test electronics you are working on. I want one just for the fact that in the future when possibly working on a portable i wont have to buy batteries to get specific voltages to test the portable. Im not an electronics expert or anything so i wont even hardly use this thing but its really just more for the fun of doing it and making it work.

timmeh87 · Post by **timmeh87** » Wed Jun 21, 2006 1:40 pm

calvary3a1 wrote:Thanks for the link. I started on those instructions but i have a few questions. first, is there any way to tell if the psu is discharged. I touched the red and black wires and nothing at all happened. I was expecting a spark but maybe im wrong. Second, I dont have all of the wires listed in that tutorial. I have red, black, 1 yellow, 1 white, and orange. Is it still possible to do it with that tutorial?

some power supplies (ie. the last one i took apart) dont even hold a charge for more than a second or two. jsut take it apart and short all the big looking caps with a screwdriver or something. even if you get a shock it wont kill you... you'll just be shocked.

you probably have a different type of pwer supply than the tutorial (or one with nonstandard colours..), look on the side of the box, there might be a label that will give you insight into which wires are what. pay attention to current rating, i believe some of them are rated for ridiculously low loads