Im trying to drive a motor with this kind of circuit since my micro is an old 8051. The voltage I use is 5V and PowerV is also 5V. I also have a 56 ohm 1/2 watt resistor in series with my motor because I didn't want to blow anything up.
Sadly, the motor does not start regardless of pin state.
When I measured the current (where load is supposed to connect) with the voltmeter, I get about 41mA and 0mA since my 8051 pin toggles between on and off at a slow rate.
I then replaced the PNP with the 2N2907 and measured current again and I got 43mA.
I think those numbers are so low with motors.
I also shorted the resistor between PNP collector and NPN base since I was using a load resistor.
I think someone suggested replacing the final NPN with a FET of some sorts, but If that's the ultimate solution then I need one with the same kind of pinout so I don't have to redo my entire circuit.
If I can get away with using a lower load resistor then I will just go for that.
So It makes me curious. Why in the attached design is there no indication of a load resistor? and why is there no indication that I need a 1/2+ watt resistor anywhere?
The original reference to this schematic is found at: 8051 - Can an NPN transistor be driven?