vc1492a / raspberry-pi-fan-control Goto Github PK

Greetings, newer Pi user here.

I'm running Linux 10 (Buster) on a Pi 3B V1.2. In Pi Configuration > Performance there's now an option to enable a fan, the GPIO and temp to trigger the fan. That would be the same (but easier) than writing the script, correct?

From my research, it seems that was added for a three wire fan (Power, Ground, Control); so if I am using standard two wire fans, I would still need to add the transistor, correct?

Second question, any problems running two 5V 0.2amp fans off of the one transistor? If so, what if I run them off of the 3.3V instead?

Excellent idea, however, the transistor is not being used most efficiently. The emitter follower configuration to handle loads dissipates more power by having a greater voltage drop between the collector and the emitter. And connecting its base directly to a RaspberryPi pin you run an extra risk in case of a burnt transistor.
You should saturate it using a configuration like the one shown here (go to "Digital Logic Transistor Switch").
This way:

• You get total protection by putting an extra (let's say 33kOhm) resistor between the transistor base and the GPIO pin.
• You've got almost-zero power dissipation on the transistor itself.
• You source the full 5 volts to the fan (full speed) with no voltage drop on the transistor.

Thanks!