pc fans with pc power supply

Hey everyone, I've seen a lot of people using 12v power supplies from radioshack and splicing them onto their cpu fans to cool their closets and boxes. Basically, I knew there was an easier way to hook up your fans using your existing computer power supply, but hadn't really done the research to figure it out.

Well, today I got stir crazy and figured it out. Its really quite simple, and I'm baffled I haven't seen this on RUI already. Essentially, all you have to do is connect the "power on" (green) jumper of your powersupply to any of the "Ground" (black) jumpers. I used a paper clip and it worked wonders. Below is a chart of a 24pin power supply, cut a paper clip to about 1.5 inches, bend it in half, and push it into the green wire connector, and any of the black ones. Remember, its the really long connector that would go directly into your motherboard.

Last thing to do is connect your computer fans to your power supply, power on and watch them blow. A note, if you don't have fans plugged in to produce a load on the PS then it wont turn on. The PS needs a load of at least one fan to run properly with this method.

yeah - this is a much better method... the small dc inverters people use from cell phones will not support much current... some pc fans use .5 amp at 12v... even the shittiest pc power supply will support 10Amps on the 12v rail...

I'm lost, do you need the computer to be on in order for the fans to run? And if so, doesn't that mean you need to change some settings in the BIOS in order for the fans to be constantly running?

Oh, and by the way, you can buy the 4-pin adapters online that convert the fan. No cutting at all.

nah - he's talking about if your rip the power supply out of the computer...

if you just try to plug it in, it wont turn on unless you short those 2 pins in the 20 pin atx connector

But you could be burning 100 watts to run a .5 watt fan doing that.

do you think it draws full current with no load?

i mean, i know they are not 100% efficient, but i know they are at least 80% - if you used an 800w power supply to run 2 fans, i dont think the PSU draws 800w... i could be wrong though.

Yea that's why I didn't say 350w.

80% power supplies are only that efficient at optimum load.