Active Cooling 5v brushless fan with Motor Speed Controller soft PWM

[MarkHaysHarris777]

   

I must apologize, I don't have my C4Labs case yet, so I can only provide a pic of this technique except with one of my Raspberry Pi(s) -- this is rasppi7.

Here I have soldered the transistor directly to the GPIO pins.  Don't get confused, the point is not the details the point is the technique -- sometimes its easier to solder directly to the pins, especially for special purpose setups like this one where you don't need to use a bus cable plug.

Some of the details are different here than in my diagrams, because here the transistor is from a different vendor and the emitter and collector leads are swapped (note how they are in a straight line--the base lead is NOT offset)... also, I'm using a different GPIO pin, to make soldering to the pins 'easier'.    

I have removed the heatsink to make the soldering more visible. I have a rather large heatsink that sits on the SoC (this is my coolest running SoC, because the space is tight, the case is well ventilated, and the heatsink sits directly below the fan which is blowing ... UP.  I might as well make a note here, that it is best to have your fan blowing UP, rather than having it blowing DOWN at the heatsink... especially if the board is in a case like this one... the fan should always evacuate the case... in this case the vents on the bottom of the case are particularly helpful.

Notice: the emitter is soldered directly to pin(9) grnd, and the black lead from the motor comes down and solders directly to the collector of the transistor. The resistor is the only connector from the base of the transistor to the gpio BOARD pin(11). The transistor rests gently top-down on the SBC. The red power lead from the motor comes down and solders directly to 5v pin(2). I'm using the very same fan_motor.sh code (Python3) except that I have simplified the motor speed control interrupt code considerably for the new PI(s) and for my PineA64(s).