Sign in with
Sign up | Sign in
Your question

Fan mod for multiple fans with auto AND manual speed control

Last response: in Components
Share
March 26, 2006 11:35:14 PM

Ok, what I want to do:
The PSU is rated for both auto and manual speed control. Thus I want both fan speeds to be automatically adjusted by whatever heat sensor controls (i.e. AMD's Cool'n'Quiet or Asus' Q-fan technology) are on the MB and adjustable through the one dial on the Tt faceplate.

What I have:
Asus A8N-VM CSM
Thermaltake W0057-01
Aspire X-Qpack

The basics:
The case comes with a pretty generic 120mm 5V case fan of the two wire variety. The PSU has, aside from it modular cables and 120mm fan, three sets of wires: a three wire set is for its 'Total Watts Viewer', another two wire set that plugs into the variable pot (or rheostat) on the faceplate and the last three wire set has the correct adapter to plug into the Motherboard's fan controller (CHA_FAN)

What I know:
I understand the basics of Ohm's and Kirchoff's law and I get the fact that things burn up when you pull to many watts.

What I need:
Help figuring out the wiring. Schematics for the PSU's fans and how I can use Asus' "expression" of the speed information.

Thanks in Advance
I'm sure this forum can figure this one out.

shorty
March 27, 2006 2:27:30 PM

If all the mobo headers support the fan control (and not just the cpu fan header) then you could simply to use a mini DPDT switch (on the case fan & PS fan) to bypass the normal fan leads. Hence, in position 1 it runs of the mobo and position 2 off the dial. Kind of nice since you can individually select which fan you want to run off the dial or both.

If just the cpu fan header is controlled by the q-fan, then I am not sure running all three fans off the cpu header is a good idea. You could create an op-amp voltage follower type circuit like this one, where the 18v battery string is replaced by the 12v leads off a hdd molex and Vin is the cpu fan +12 lead and Vout is the output of all the fans combined.

For my rig, I also wanted multiple fan control w/ temp monitor so I just got an Aerocool Gatewatch, independent 4 fan / sensor capacity. Works well.
March 28, 2006 4:44:10 AM

What I was trying to say about the PSU is that it is temp sensitive and manually controlled. I think the PSU regulates the voltage but I can change the resitance with the dial. Does this sound right for thermaltake's TWV 500 (W0057)?
March 28, 2006 5:20:48 PM

Well the rheostat is probally connected to some type of voltage regulator of some sort - difficult to tell since I could not find a schematic or any details from thermaltake or some quick web searches.

I did come across a good article on fan speed control at analog.com, it may give you some insight on how the TWV does it's thing after looking at how it is wired and what chips it uses for fan control.
!