OK, quick (I hope!) question:
PWM makes controlling speed of a DC motor via micro controller easier. I get that.... i think.
But in terms of benefits of PWM, I thought they were that PWM gave peek torque at low rpm, but as I've learnt in practice, this isn't true as the motor 'sees' simply an average (lower voltage), and hence using lower current to drive the motor at slow speeds - is that right?
So, why is PWM used in all sorts of DC drives from drills to robots as (presumably) you could have speed control via potentiometer controlled high gain transistor (either current BJT or voltage controlled FET I assume??) to control a DC motor while burning minimal resistive energy in the low current pot side.
So is the real reason for PWM popularity that a lot of devices these days use battery power and so need to conserve maximum energy, or is there an actual mechanical advantage, eg more torque at low speed or something I have not considered? Like I say, I've measured the torque of a 12v motor using PWM and half fixed voltage and they seemed the same to me.... I thought things like drills use PWM instead of a pot controlled transistor to get low speed torque but I think I may have got that wrong. Please confirm, someone?!?!?!
Many thanks if you can answer this helpfully!