In the early days of cool'n'quiet ATX PSUs; the fan control circuit was on a small bit of PCB fixed to one of the heatsinks, it was just a couple of transistors and a few resistors. It was pretty easy to hand trace the circuit.As the topic says, I'm trying to build a little circuit but I don't know how to short circuit the resistance and calibrate the lm35 temperature to desired value .
Please help