PWM frequency and DC motor speed

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i experimenting powering dc motors, , seeing don't understand.

i running 24 volt motors.  did test several different pwm frequencies.  frequencies, sent motors 9v (verified on voltmeter).  using "phase correct" or "dual slope" pwm.

at 31khz pwm frequency, motors didn't move.
at 3.9khz, moved @ moderately slow speed.
at 490hz, spun quickly!

i verified frequencies voltmeter.

also, running motors @ 3.9 khz non-arduino controller (i didn't build other controller, able verify pwm frequency oscilloscope) - motors spun faster arduino sending them 3.9 khz, not fast when send them 490hz.

what explain this?

if matters, controlling them pololu drv8801 motor controller.

i'm no expert, intuitively seems correct me. motor surely needs time react high part of pulse start moving, , if high time's short motor won't react.

i assume there's reason arduino frequencies 490 , 980hz: presumably work enough purposes.


Arduino Forum > Using Arduino > Motors, Mechanics, and Power (Moderator: fabioc84) > PWM frequency and DC motor speed


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