how do u turn on an AT power supply?

[Lt. Max]

my friend is tryin to make his 48vdc blower fan to work so his takin power supplies and gana hook the +12 and -12 of them together to get 48v. one of his psu's is at tho, so im wondering how would you turn it on without a mobo anyone kno? i kno atx is pin 14 and 17

max

[Diggrr]

AT power supplies should have a "push on, push off" button wired to them with the rest of the wire harness. It should be pretty hard to miss since the wire is made to reach all the way to the front of the case....It's usually a foot long shrinkwrapped wire with the switch on the end of it.

[Lt. Max]

o yeah..of course.

thanks

max

[Ange]

Explain to me how with +12V and -12V you wana get 48V ?????????????


A.

[Lt. Max]

if u put 4 together it should combine to 48v..
right?

max

[RCtruckguy]

no you should only need 2, if i put neg on -12v and pos on +12v (on a multimeter that is) i get 24v. good luck~RCTG

[Diggrr]

I wouldn't involve the -12 volt wires. They usually can handle less than an amp before they let the smoke out of your psu....that would be sad, very sad.

But yeah, if you run one psu's + to the next one's - and bridge them all together, you'll prolly get just under 48 volts. Alot (not all) of psu's won't put out full power without a load on the 5 volt side. You have to test to find out....I have 2 that will put out 12, and 3 that won't.

[Lt. Max]

i c. i will tell my friend to try ur idea. thanks,
so i run yellow, black, yellow then (he will try with 3 psu's first so mab it will b less noisy.)
but what about like the neutral? like those will go to the hot wire on the fan.. what do i do with the other?

max

[Diggrr]

For powering the fan (with two wires):
fan red>(1)yellow-(1)black-(2)yellow-(2)black-(3)yellow-(3)black>fan black
where the (1) is psu number one, (2) is psu number two etc...

By the way, whilst on this subject...I'm not sure about the psu's built in grounding. You see, when using them in combination (same voltage but more amps) you need to butcher them slightly to make sure that only one power supply has a pcboard to chassis ground. Maybe that's included in that article I'd read on procooling.com. Maybe you should check it out, in their articles section.