Hi All,
I wrote a program to control a small brushed 12V DC motor from PIC16F627A through a USART via PC serial port. now its working properly.
but the problem is, I've set 10KHz as the PWM frequency, and in lower speeds, an audible noise, (a high frequency noise) is emitting from the motor. but the motor is running smoothly, accelerating, decelerating properly. all in all, the motor seems to mechanically has no problem.
will the 10KHz damage the motor windings?? coz I have heard high frequencies are likely to damage the insulation of windings?? is it true?? if it is likely to damage the motor, how can I find the safe PWM frequency??
and finally, pls tell me what are the considerations if I'm going to implement this to a 220V DC Shunt wound 8.3A motor. I'm going to drive it from a power MOSFET. and I'm very thankful if somebody can provide me with a schematic of the power section.
Thank you
Nimesh