How to connect computer fans to an electrical supply

10" Red Devil

New member
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!
 

Kenzy

Premium Member
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

New member
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

On Yer left!
Premium Member
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

Premium Member
:thumbsup: 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.
 

TheVillageIdiot

New member
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

New member
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

New member
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.
 

10" Red Devil

New member
<a href=showthread.php?s=&postid=7514750#post7514750 target=_blank>Originally posted</a> 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

In Memoriam
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.
 
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