2003-06-06 03:17 AM
maximum motor speed given pwm frequency
2011-05-17 01:16 AM
Hi
I am wondering is there an easy way to determine the maximum speed of a motor in rpm, given the pwm frequency? Or even the other way around. Given a motor speed, calculate the the pwm frequency. I would like to calculate the pwm frequency for a motor with 4 poles running at 80,000 rpm. Is there any documentation on this sort of thing? Thanks.2011-05-17 01:16 AM
Hello!
The speed is not related to the PWM frequency but to the PWM duty cycle and to the step time (meaning the time between 2 commutations). Example for a BLDC motor: For a 2P Poles MOTOR at N (rpm) targeted speed: Step time St = 60/ (N*6*P). What kind of motor are you talking about? What is the micro you are interrested in?2011-05-17 01:16 AM
Ok, thanks for the equation. I think that will answer my question. I am currently using the st72141 and the motor will be a BLDC.
Thanks for the help. John