kinarfi
Well-Known Member
On an earlier thread, FET Killer, we got into proper PWM Frequency for driving a motor some what. It was suggested to stay above ~ 20KHz so you wouldn't hear the buzz from the PWM frequency, It was also said that the LM339 I'm using may not drive the big power FET into saturation fast enough creating heat by being in linear region for too long.
My thoughts on this is that the more times you pass through the linear area per second, the more heat generated, for example, if you run at 1 hz, and take 1 msec to saturate, you will create 1/10 the heat of running at 10 hz. Change these number to real life scenarios of something like operating at 1 KHz instead of 20 KHz and you have 1/20th of the heat. Other than being able to hear the motor buzz at a 1 KHz frequency, if you're close enough to hear it, are there any other factors to consider?
Hope we can have a good discussion on this.
Kinarfi
My thoughts on this is that the more times you pass through the linear area per second, the more heat generated, for example, if you run at 1 hz, and take 1 msec to saturate, you will create 1/10 the heat of running at 10 hz. Change these number to real life scenarios of something like operating at 1 KHz instead of 20 KHz and you have 1/20th of the heat. Other than being able to hear the motor buzz at a 1 KHz frequency, if you're close enough to hear it, are there any other factors to consider?
Hope we can have a good discussion on this.
Kinarfi
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