I've used the circuit as the above link but instead of an 2N700 MOSFET I've used a BS170 but no go. When putting that circuit in the Pwm output at 0% the fan it's stopped and at 0.5% it goes full power, I've measured in the oscilloscope and I have a straight line at 12v (no pwm). Also tried with a BC547c and no go, the same thing. Is this related with the Pwm being ground switched?
