martin5504 wrote: ↑
Thu Sep 13, 2018 7:02 pm
Understood, but for only shutting and turning on the fan is enough only the transistor right?
no to control the fan or even to just turn it on or off you need the extra components.
if you just want the fan to run at a constant speed you could just use this circuit, the fan will be on as long as the pi is powered.
the value of R ? will have to be found by experimentation, but 22Ω might be a good starting value going lower for higher speed or higher for a lower speed.