Can I control the speed of three fans using this?

Moothead2

Moothead2

Moothead2

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Plug the three pin connector to my motherboard and control the three fans connected to this in the bios and plug the spare molex at the end into my PSU.
 
That I think won't work, you would need the live coming from the fan header going to the fans, at the moment you would only be reading the fan speed, not controlling them.

Edit: is the fan header connection only have 2 wires?
 
RJC is correct, All that would do is tell you the RPM of the fan that is connected at the top. Those 3 pin fans are controlled by varying the voltage to the fans,.
 
Nice try though.

The only way it could work is by some swapping over of wires in the two fan connectors at the top, then not plugging the Molex in at the other end.

Not sure I'd be happy connecting three fans to one motherboard header though.
 
Except what you have is not PWM.

If it was, 4th pin (PWM) to all 3 fans to one motherboard pin.
12v and gnd to molex
gnd to motherboard pin.

Thats the only way. I would stick an RPM sense on one of them, but not all 3.
 
Moothead2 said:
I was trying to emulate this: http://www.overclockers.co.uk/showproduct.php?prodid=CB-031-AK So I'm guessing 3 fans off one header and a molex is safe enough.
Click to expand...

With the PWM splitter the motherboard connector only feeds PWM signal to all the fans and the speed sense from the CPU fan. The Molex provides power for all fans, not the motherboard.

General consensus is that motherboards output about 1 ampere to a fan connector so provided fans attached are less than this, and this includes initial current then they can be used.

Having less than 12v at one end of a cable and 12v at the other would not be a good thing I'd imagine.
 
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