Circuit is for controlling the fan on a Raspberry Pi, just on/off according to temp, no PWM. Not sure about the diode as it has a .7V drop and it’s a tiny brushless DC motor. No markings on the fan so I measured the current with a multimeter when hooking it up to a USB charger. Circuit was adapted from here using what I have...
Doing some quick math, the transistor will have a base current of 5 milliamps, which a Pi should be able to supply. At a fairly typical beta of 100, the transistor could drive the fan at up to .5 amps, which is plenty for a small fan. A MOSFET transistor is generally better suited for switching high current loads, but for this a BJT (as drawn) should be fine.
microsoft-ies 🍵 (lemmy.world)
Small fan switch sanity check. (lemmy.world)
Circuit is for controlling the fan on a Raspberry Pi, just on/off according to temp, no PWM. Not sure about the diode as it has a .7V drop and it’s a tiny brushless DC motor. No markings on the fan so I measured the current with a multimeter when hooking it up to a USB charger. Circuit was adapted from here using what I have...