I would like to use an old 100w (max) computer power supply to power a few computer fans I have in a growing operation. This apparently isn't the method that most use, but it is the method I would prefer to use because I already have everything I need so it would cut down on costs. My question is: How do I modify the power supply to power the fans when it is plugged in? As of now it won't work because normally the power supply connects to the motherboard of a computer, requiring you to turn on the computer. So how can I make it supply the power as soon as it is plugged in, or alternatively, integrate a toggle switch to turn it on? I know that some power supplies actually have a switch on them so it can be done, but unfortunately the one I have does not.
you're going to have to short out one of the pins that connect to the motherboard so that the power supply thinks it has a connection.
All you need to do is take a paper clip and connect it from a black wire to a green wire on the ATX power connecter (20 or 24 pin--or the big plug if you don't know what I'm talkin about). Here's a vid to show you... [ame="http://www.youtube.com/watch?v=weroTqTMPl4&feature=related"]YouTube - How to jumpstart power supply[/ame]
Connect the green wire to any black wire... check out this video [ame="http://video.google.com/videoplay?docid=3862247854017006442&ei=IUInSuuOMJ3UqAOc0Z2ICQ&q=power+supply+without+motherboard&hl=en"]Jump Start your Power Supply[/ame]
lol... 5min late I would say that since nobody said anything about it, make sure you don't do this with the power supply plugged in!
thats awesome... Thanks for the youtube vids. This is perfect for my carbon scrubber box (now I don't have to run a motherboard inside of it as well)