Bench Power Supply for 10$ Computer Power Supply HowTo

[PedroDaGr8]

That may be an EPS PSU which is a form factor common in servers. Do you have any pics of it assembled (the top half WILL be needed, likely one side is the primary side and the other half is the secondary). It looks to me like btoh of those wires plug into the other half of the board. If so is there an external connector?

EDIT: I saw pictures and it has a 36pin external connector. Unfortunately, there is no pin-out listed that I could find. Which means that you will have to go through the 36 pins and figure out what is what.

EDIT2: One more thing. The EPS standard uses the same 24-pin plug that ATX does plus an 8-pin aux cable. This takes up 32 of the said pins. The rest are likely for connecting peripherals. So just go through and find which pins have 12V on them. One thing I don't like is this one doesn't say how many 12V rails there are. if there is only one you should be fine but if the rail is split, then you end up with only 8A on one rail. My guess is it isn't but who knows. Also, this thing has an insane amount of 5V amperage.

[Transeunte]

I have just read this whole thread (well, took almost a whole afternoon LOL) and still couldn't get my PSU to work:

It is a regular 300W ATX one. It powers up (the cooling fan spins) just by shorting Green + Black. But it won't do anything else excep powering some LEDs

First, I tried lighting up a regular 55W "Big" Halogen lamp (regular H7 headlight lamp) on the +12v line, and the PSU shut off. Following advice to load the +5v line, I plugged a 21W "Small" Halogen (regular turn signal bulb) on it - nothing happened, no light, but the PSU kept running. Then, when I tried to rig the 55W Halogen again, the PSU shut off again.

Then I tried wiring the Small bulb to the +12v line (just for science) and the PSU shuts off as soon as the bulb starts to glow (about 1/2 second after pluging the lamp).

I have some very old LEDs here salvaged from some 1980's TV and PC, and all of them are lit by the grey wiring (wich means the PSU starts up just fine). Regarding voltages, I don't have a multimeter but a LED digital voltimeter: It shows 5.67v @ Red Wires (a little high, uh?) and 11.38v @ Yellow (a little low, uh?). BTW, the PSU shuts off also whenever I short any of the +5v or +12v leads, wich seems to indicate at least some of its fault protection is working fine.

So, is my PSU dead? Is there any component that should be looked after?

It's been stored on the garage for too long and maybe it was already damaged when I first stored it, but would be nice if there was any way of fixing it. Thanks!

Oh, and the ratings on its outside are: 115v/230v, 7/4A - Output 300W / +5V: 25A / +12V: 10A

[xfactoraeg]

Meant to post this awhile back, but thanks OP! Turned an old old old 200w AT psu I had into a working bench power supply, works awesome esp since it has a beefy on/off switch built in. I do admit being a bit nervous the first time I fired it up but all's good. Comes in handy, that's for sure.

[RR5]

Going to revive this thread. I picked up some 2003 BMW M3 headlights and wanted to test them. I just needed a way to wire up the PC power supply to the BMW headlight ballast. Turned out I needed two MiniGrabber to MiniGrabber test leads. MiniGrabber to Aligator clip might work better because the two pins on the ballast make it tricky to grab using the minigrabber. I was lucky to have D-SUB Crimp Female Pins laying around. Using these I popped two on the pins which I could grab with the minigrabber. Presto, headlights lit up no problems! Thanks OP!!!

[PeakOilLover]

So I tried to do this last night with an ATX unit and ran into some problems. I terminated all of the wires to the ATX plug (spliced the green and black together) and kept one of the Molex connectors. Wired the red and one black to a turn signal bulb and used the yellow and other black as my 12v leads. Turned on the unit and it worked great. Fan ran at full speed and the signal bulb lit up great, but as soon as I put power to my ballasts, the psu shut down and I cannot get it to restart. The fuse on the board looks good. Let me know what ideas you may have. Thanks!

[ultraviolet]

I ordered a power supply from Newegg on sale for $14 and did the mods. I added some jacks into the side of the enclosure for power and ground. Works great!

[Vital]

This thread rocks!!!
Finally found use for my old computer I put away in storage years ago!
Got me 2 separate 12V lines and 2 separate 5V lines. AWESOME!!

[gorbys]

Yeah, I made my own to since I never got around to using the chieftec in my HTPC build. So here it is, also I DID NOT load the 5v line with anything and everything was fine and stable


and the rx-afs


Just need to clean up the wiring, buy some connectors and make a case for this and I have myself a working 12, 3.3 and 5 volt supply

[Vital]

^^^ How did you get 3.3v?
I know my unit is also rated to put out 3.3, 5 and 12 but by connecting black and green wires as per instructions I only got 5 and 12, don't see 3.3 anywhere.
Not that I really need 3.3 but I'm sure one day I'll find use for it.

[gorbys]

^^^ How did you get 3.3v?
I know my unit is also rated to put out 3.3, 5 and 12 but by connecting black and green wires as per instructions I only got 5 and 12, don't see 3.3 anywhere.
Not that I really need 3.3 but I'm sure one day I'll find use for it.

The S-ATA connectors have a 3.3V Output, also the ATX connector should have 3.3 but I didn't test that.

EDIT: BTW it's the orange wire on the sata connector and the 3.3 is also orange on the atx connector.