I have a PC fan controller that is capable of powering 10w per channel. I'd like to put 23w of fans on a single channel, so I am trying to find a way to use the electronics already on the fan controller to activate a MOSFET or other transistor that will be able to handle 23+w.
Basically, the theory I thought would work is to look at the PNP transistor on the fan controller, and take a wire from the gate of that transistor and using it as the gate on the MOSFET to make the MOSFET switch quick enough to step the voltage and vary fan speed.
Unfortunately, doing this did not result in what I wanted to do. The fans spin at a constant rate of approximately 60% top speed. I only have one fan tachometer wire wired to the feedback of the fan controller, so it doesn't get any weird signals from out of phase tach signals.
Is there any good way to accomplish this?
Here is the equipment I am using to test this with.
Fan controller: [BitFenix Recon]
PNP Transistor in fan controller: B772 PNP Medium Power Transistor