As above. I am trying to use a pc power supply to power a pc fan fume extraction system on the bench. The problem I have is that the motherboard normally switches the power supply on. Does anyone know which of the big bunch of wires which normaly connect to the motherboard acts as a switch?? I guess it is a relay type job??

Thanks for any help!!

Rupert

this didn't used to be the case, older supplies used to have a hulking great switch. Now they are all soft switched.
Which is why i used to keep a few old ones

Unfortunately I can't help you though good luck

"To power up a stand alone PSU for testing purposes, you need to short PS_ON pin with one of the common pins. Normally, PS_ON is activated when you press and release the computer power button while it is in standby mode."

If you believe

http://www.smpspowersupply.com/connectors-pinouts.html

anyway

green to common? i seem to remember

Hi

Have a look at this:-

http://www.rcracechat.com/vb/showthread.php?t=2129

It tells you how to turn an old ATX PSU into a basic 12v bench unit.

One thing to be careful of is many PC power supplies don't like being run without a load on them even for a short time. In the rcracechat article the bulbs do that job.

Take a look at Powering on an ATX PSU without a motherboard

Brilliant!! Thanks... Will have a read!

My water pump came with an adapter to fit onto the big connector that goes to the mobo so you can test the pump system out without powering on the computer (check for leaks etc) Does the same as the link f1ngers posted

Yeah, green the ground.

Only further thing, that wont affect you, if that they dont like being too unevenly loaded. So often to get a decent whack out of the 12v line they need a 100watt resistor across the 5v line.


Daniel

This is mine, turns the power on...

quote:

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Originally posted by JimSpencer
Hi

Have a look at this:-

http://www.rcracechat.com/vb/showthread.php?t=2129

It tells you how to turn an old ATX PSU into a basic 12v bench unit.

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