How to connect computer fans to an electrical supply

[10" Red Devil]

Hello,

I want to add computer fans to my lights of america model no. 9266 65 watt pc lights by cutting a hold in the size large enough for the fan and gluing it to the fixture. But I am unsure how to get the fans connected to some juice, as you know they have a different type of plug made to connect to a pc power supply.

Thanks in advance for any advice!

[don954]

just go to radio shack or online and get a 12V DC power supply/transformer (wall wort). Splice the wires into the power supply, red is positive and black is negative.

Here is one from radio shack, you can get much cheaper elsewhere but this will give you an idea of what to get:

http://www.radioshack.com/product/in...entPage=search

[10" Red Devil]

Don,

Thanks man!

[Kenzy]

I just picked up a new PC fan that I was going to try out, it has three wires, red, black and yellow. If the red and black are pos and neg, what would the yellow be for?

[scrager]

yellow is a speed control for motherboards that support it. it's not needed if you want the fan on full speed.
i'm not sure how it works to control the speed if you wanted to do that.

[sjm817]

Yellow is for rpm measurement. Not needed. I would also recommend an adjustable PS. If the fans are too noisy @ 12V, you can kick it down to 9V or 7V to quiet them down.

[Kenzy]

Thanks that makes sense. Heres the fan that I picked up Link
I'll need to come up with some sort of bracket but that should be pretty easy.

[BrentN]

Any con's to using a power supply out of an old PC? no splicing required.

[nodbugger]

Heat and size.

[TheVillageIdiot]

how do the pc power supplies work, do they always draw their rated wattage? if it's a 400 or 500w supply, well, that's a lot of amps being taken up just to run a few fans.

[dillycheeze]

PC fans running straight from a AC to 12V DC are usually pretty loud....i put a 100ohm resistor on mine and it still moves a lot of air but much quieter.......that would probably save $ over an adjustable AC-DC unit......resistors are dirty cheap......and before you go buy the AC-DC unit.....look around the house first, you probably have 20 of them

[rutledgek]

I got a pretty cheap adjustable power supply off of ebay. I like it because I can adjust the speed depending on the mabient temp of the room. On 90 degree weeks i have it all the way up(after I got home one day and the tank was 87). During most of the winter spring and fall the lowest setting that will still run the fans is used.

[JPA]

An old cell phone charger will work also. They are usually 9 volt.

[10" Red Devil]

Jpa,

Good idea man!

Thanks.

[10" Red Devil]

Originally posted by dillycheeze
PC fans running straight from a AC to 12V DC are usually pretty loud....i put a 100ohm resistor on mine and it still moves a lot of air but much quieter.......that would probably save $ over an adjustable AC-DC unit......resistors are dirty cheap......and before you go buy the AC-DC unit.....look around the house first, you probably have 20 of them

Sorry complete noob,

Where would you find one of these and how would one hook this up to electricity, etc.

Thanks for more details please.

[AZDesertRat]

A variable voltage DC power supply is $5 at Harbor Freight Tools and not much more at Wal Mart. They work great and make the fans totally silent. I use Vantec Stealth 120mm fans rated at 28 dBa so they are pretty quiet to begin with.

[quiksilver]

you can buy cheap resistors at any local radio shack for really cheap

[10" Red Devil]

How do you connect the fan to these resistors and how intern do they connect to a power source?!?!