I have a Delta 120mm 151.85CFM fan, but I want to run it with less vol

[GermaniumGenie]

I saw a guide on here that tells how to change the amount of voltage that a fan uses. I didn't really understand what it was saying; it just had pictures. I have this Delta fan (http://www.sidewindercomputers.com/de12ff.html) lying around going to waste because it is so loud. How to I make the fan use less voltage so it runs more quietly? Thanks.

[davidhammock200]

Buy a Sunbeam or Vantec Nexus fan controller. :nod:

[GermaniumGenie]

I know I can do that, but isn't there some way I can decrease the voltage to the fan by altering the wires or something?

[davidhammock200]

I know I can do that, but isn't there some way I can decrease the voltage to the fan by altering the wires or something?

If the fan will run on 5V then this 5V trick will work,

the 7V trick depends on the PSU & the only way to know is to try.

 

Links at end of DFI N4 PS Guide.

 

http://forums.extremeoverclocking.com/show...4&postcount=297

[MaKo]

The pictures are showing you 3 possibilities for delivering voltage to a fan. The molex plug on the left in each picture is from your power supply. The one on the right would go to your fan.

 

First picture shows normal 12v operation setup where the yellow wire on the left is 12v and the black is your ground. Second picture shows a 7 volt setup where you are still using the 12v lead from the PS, but now you are moving the ground reference to the 5v supply. This will give you a 7v output to the fan. 3rd pic shows normal 5v setup.

 

I would choose the 7v setup. I have used this with Vantec Tornadoes many times and works well to quiet them down.

[Autochthon]

What's the amperage/wattage of that fan? You can build a very simple circuit using a very basic power transistor (TIP51C or comparable) and a small heatsink that will allow you to control the fan indirectly (using software) from one of the adjustable fan headers on your Motherboard

[MaKo]

That fan draws a little over 1A so that's a no go for a MB fan header.

[davidhammock200]

The 7V trick will work with some PSU's, but not with others.

If the PSU just won't boot/power-up after doing it, just undue it.

 

GL

[exscape]

I'm not that into electronics, but I think running such a huge fan at 7V wouldn't be too good for the PSU, since you use the 5v rail instead of GND. Then again I'm not sure...

[davidhammock200]

I'm not that into electronics, but I think running such a huge fan at 7V wouldn't be too good for the PSU, since you use the 5v rail instead of GND. Then again I'm not sure...

It won't "hurt" anything, but it will not work with all PSU's, depending upon their internal set-up.

[Autochthon]

That fan draws a little over 1A so that's a no go for a MB fan header.

 

The point of using the transistor is that you CAN plug into the header and only draw a trickle from the header. The power is amplified by the transistor. The tip51C I mentioned can handle up to about 3Amps so it will work fine for a 1A fan. The only problem is you will need a small heatsink to cool the transistor as it will need to dissipate more heat than the transistor can do on it's own. I'm currently running 2 of these circuits to run two seperate 1A + circuits off of the CPU and PWMIC headers on my board.

[MaKo]

Roger that Autochthon. Power transistor would work in that situation.

 

Curious how you mount your setup though? What package is the 51c? Was looking on the TI site for the spec sheet and not sure which one you are using.