Kirk Wallace wrote: > Just in case, one of my Pico PWM amps needed to be modified to run a > motor continuously. The large motor output filter inductors would > overheat fairly quickly. This isn't a problem for axis motors that > usually are not on for very long. Jon suggested removing the motor > output capacitors. I'm not sure what happens with EMI with these > capacitors removed, but it does allow the amp to work with a spindle > application. Newer amps may not have this problem. > A long time ago I reduced the value of these capacitors (C14 and C15, right next to the motor power connector) to get rid of this heating problem. I might end up reducing the value again by a small step. The worst case is where the PWM duty cycle is 50%, then the inductor sees a triangle wave current at 50 KHz. This would be the case where the motor is running at about 50% of the DC supply voltage.
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