shehry

i was developing a motor control using pwm. and i have a 12V 6A DC motor. could anyone direct me as to what would be the appropriate pwm frequency?

Nigel Goodwin

If you go too high then the inductance of the motor starts to have an effect, losing power and making the motor dissipate more heat - this isn't a good idea!. Going too low may make it jerky, so too low isn't good either.

I would suggest probably the low KHz range is a reasonable area, but you need to keep an ear open for audible effects from the motor - this is quite common in variable speed cordless drills!.

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ivancho

I have found that using a frequency between 10KHz and 15Khz has worked with most of my applications.

You can look on the internet for PWM frequencies and you might have a hard time finding a straight fits all rule of thumb. There is a lot going on with PWM that you might or might not want to know. My suggestion give it a try, start with the 10Khz and go up. Some people have used 30Khz, it all depends.

Make sure that you have those protective dioes, since they will be important. Check your IC to see if they are included internally otherwise make sure to have some fast switching diodes that handle the spikes.

Good Luck

mfaradays

When choosing your frequency, u must bear in mind that at some point in time u need to send 50% duty to stop. If your frequency is in the audiable range this is very irritating. So u need something above 18KHz atleat.