Howdy,
I am designing a circuit to switch on and off a computer fan with an NPN transistor. I am wondering if I should use a diode across the computer fan, to protect the transistor agains trainsients from switching (if the fan behaves as an inductive load).
Thanks for any advice on this,
Jon
Even if the fan contains a brushless commutation circuit. it probably exhibits some inductive behavior at the supply terminals. I would add the diode.
Sorry, but on thinking about this a bit more, any brushless driver will probably act as a diode across the motor, when power is disconnected.
Try watching the voltage on a CRO as you switch it off (with a switch) - if there is an inductive kick it should be visible.
or use a diode anyway, to be sure to be sure. They're cheap.
NPN
Thanks, John, and Rebel. I'll probably just add the diode just to on the safe side.
Thanks,
Jon
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