Circuit For Monitoring The Operation Of An Electric Motor

摘要

A circuit for monitoring the operation of an electric motor comprises means for deriving a motor signal indicative of a relatively low frequency characteristic of the motor commutation current (for example the back EMF ripple) by rejecting the high frequency components which are mainly the result of the commutation events. The circuit also includes means for producing a pulse from the low frequency characteristic which has a duration related to the motor speed.