DC motor fault monitoring circuit - has tachogenerator connected to adder and two comparators connected by gate to flip=flop

摘要

The fault monitoring system for a d.c. motor includes a tachogenerator (TG) coupled with the motor (DCM). A control signal (SPC) is applied to an adding stage (AD) connected by an amplifier (AMP) with connections across the motor. The tachogenerator is connected back to the adder. A reference signal (A) is applied to the motor with a connection (Vr1) to a comparator (CMP1) and a signal (B) corresponding to the motor speed is connected to a second comparator (COMP2). Both comparators are connected by a gate (G1) to a flip flop (FF1). When a fault is indicated by the tachogenerator, an alarm signal is given by the flip flop. The system can be used for a motor rotated in either direction.