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

[MarkHaysHarris777]

Hi Marcus, I have some questions on the setup.  You mentioned either the 2N2222 or PN2222.  Does it matter which is used, or is either one fine?  I get that the pins are different, just curious if it matters which one is used.  Also, can this be used with Android images or is it only good with Linux OS?  Thanks.

hi , the 2N2222 and the PN2222 for functionally equivalent NPN bipolar junction transistors designed as general purpose amplifiers and high speed switching. You can use either one... and there are other NPN transistors that will work just as well too;  the reason for the 2N2222 is that they are plentiful and dirt cheap.   Often in a grab-bag of 2N2222 the PN2222(s) will also be mixed in...   the collector current can peak at 1A, and it will sustain 800ma... so this also works well for the 450ma cage fans too. Try to find a grab bag of maybe 20-30 transistors... you'll get them way cheaper ...

You can use the same technique with Android; however, you may have difficulty supplying the pwm signal from Android... that does not mean you can not accomplish the technique, only that somehow you will need to provide the pwm signal from someplace else (an inexpensive way to do that is to have a 555 timer provide the pwm signal through a buffer driver... to turn the transistor on and off at about 50 hz;  you will want a circuit that will have between a 60/40 up to an 80/20 duty cycle.

edit: one person reported to me that the NPN nte123ap worked fine too.