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PWM vs. Linear Amplifier effect on motor efficiency and heat losses in motor coils

PWM vs. Linear Amplifier effect on motor efficiency and heat losses in motor coils

PWM vs. Linear Amplifier effect on motor efficiency and heat losses in motor coils

(OP)
Hi
I have a question related to PWM vs. Linear Amplifier. I know the PWM amplifiers run cooler than standard linear power amplifiers and hence the PWM amplifiers has higher efficiency. I am wondering what about the motor itself. Are both PWM vs. Linear Amplifier produces the same heat losses on the motor?

RE: PWM vs. Linear Amplifier effect on motor efficiency and heat losses in motor coils

Somewhat higher (a few percent) losses when you run the motor on PWM. But the losses in a linear drive, if anyone should ever get that idea, are enormous. At low speed, the losses are approaching 100 percent.

Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

RE: PWM vs. Linear Amplifier effect on motor efficiency and heat losses in motor coils

I agree with Skogs. There are slightly greater losses in the motor due to the current ripple from the PWM, but the losses in a linear amplifier are FAR greater than in a switching amplifier.

Linear amplifiers are real specialty items now, really only used in super-precision applications that cannot tolerate the vibration or EMI from a switching amp.

Curt Wilson
Omron Delta Tau

RE: PWM vs. Linear Amplifier effect on motor efficiency and heat losses in motor coils

(OP)
Many thanks for Skogsgurra and cswilson

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