PC Power Supplies

[Larry]

Is there anyway to make a PC Power Supply work w/out it hooked to the Motherboard on a Computer? I have one that was converted a few years ago for me & I use it to power a lot of layout structure lights. That unit has 8 diff. voltages in output & I use 4 of them.
I now have about 10 Power supplies that I need on the layout & all are fan cooled. Suggestions much needed.

 

[Larry]

I looked up on the website "How Stuff Works" & it said that the PS needs 5volts to make it turn on & even after you turn off your PC the PS stays on for a short time. If I knew which circuit to feed the 5V. from the PS to that wire I could probably make this thing work. Also, if I use a female plug from a Motherboard to plug the main plug from the PS, do you think this would make it turn on? When you test a PS w/a tester the main plug has to be plugged in to make the rest of the plugs work.
I hate to not be able to use these PS's since I get them for free. The cheapest one new is from $80.00 & up. You can buy them for $10.00, but they don't have the various voltages.

 

[RW&C]

I have a PSU hooked up as a bench power supply for testing stuff. It's pretty easy to re-rig one of these.

There's a wire coming out, grey or green depending on brand, which has to be connected to ground for the supply to start up. I just wired mine to a SPST switch on the front (put it where the input voltage switch was). I build mine from instructions on instructables.com.

I also found out what each wire/voltage was. It's got 12v, 5v, 3.3v, 12v+, 5v+, and a couple other weird bits. I just hooked it all into a terminal strip, which allows me to easily hook up whatever I want. It had a sticker on it which spelled out the max current for each connection. When I cleaned/partially painted the case I just re-wrote all this down in Sharpie.

 

[gravel]

Search “lab power supply from computer power supply”. There are a few “how to's” on Google and YouTube. Depending on how you run the wires out the back depends on the cost but should only cost a few $.

 

[Larry]

Thanks Everyone for the exc. response's. I'll do the switch for ea. one. I don't know why I didn't think of that part. I'm usually pretty good w/electronics. Must be old age. All of mine have the voltage color codes w/the wire & tell if they are pos. or neg. I also have an Amp/Vol. meter which I use quite often.
Thanks again.
Larry

 

[jdetray]

The R/C aircraft folks have done a lot of work with PC power supplies. Here are a few discussion forum threads on the topic of converting a PC power supplies for use as general-purpose power supplies:
http://www.rcgroups.com/forums/showthread.php?t=368639
http://www.rcgroups.com/forums/showthread.php?t=315179
http://www.rcgroups.com/forums/showthread.php?threadid=55555
http://www.rcgroups.com/forums/showthread.php?threadid=114054
http://www.rcgroups.com/forums/showthread.php?threadid=41161
http://www.flyinggiants.com/forums/fg189/12159-frankenpower-building-12v-power-supply.html


In addition, here are some helpful web sites on the same topic:
http://web2.murraystate.edu/andy.batts/ps/powersupply.htm
http://web2.murraystate.edu/andy.batts/ps/DESIGN_GUIDE.HTM
http://www.marcee.org/Articles/PCPowerSupply.htm
http://www.extensiontech.net/articles/howto/jb/pstu/
http://reckerclub.tripod.com/id105.html
http://homepage.ntlworld.com/fast.electrics/PSU.pdf

- Jeff