ATX PSU pinout question.

[golfcart]

Anybody know which pin/wire on an atx psu is always hot when it is plugged in? I'm working on a little mod here and it would come in handy

[Siliconjunkie]

So you want a hot at all times? Not just when the PSU is on?

[golfcart]

Yeah, I need the one that is +v when it is plugged in. I have an old keyless entry system from a car and I am going to see if I can get it to start my computer

[Kc2iLq]

Keyless entry from a car to start a computer? Easy!
Wire up the receiver to a NO momentary relay and have the relay close the "power switch" poles on the mobo.

-Kc2iLq

[golfcart]

Kc2iLq, Thanks, but I have that part figured out. I just need to know how to get power to the receiver when the pc is off

[Omardeth]

neat

[Siliconjunkie]

Get out your trusty DVOM and start checking. Shouldnt take but a few min to find it. I found a PDF of the ATX spec but its overly technical.

[Xeroid]

Pin #9, +5VSB (purple wire), max current 1.5 amps on a 300W power supply. This can be found in section 3.3.3 of the ATX12v Power Supply Design Guide. You can download the .pdf at www.formfactors.org.

Mike

[golfcart]

Thanks Xeroid, It seems to be the right wire, but it's not enough juice to close my 12v relay I guess I am going to have to try to find a 5v somewhere..