Patent attributes
A system and method detects coil-to-coil faults in an electric motor having a plurality of coils. The method includes applying a square wave signal to a first coil of the motor, connecting a capacitor and a resistor between ground potential and a second coil of the motor, applying the coil output voltage to an amplifying and peak detecting circuit, applying an output of the amplifying and peak detecting circuit to the input of the control unit and, after a delay period, generating a motor fault signal if the coil output voltage is below a predetermined threshold. The square wave signal is amplified by a circuit which prevents transmission of voltage signals from the coils to the output of the control unit during normal operation of the motor.