DETECT STEPPER MOTOR MOVEMENT BY SENSING INDUCED EMF ON MOTOR WINDINGS

摘要

An apparatus for and method of monitoring the operation of a stepper motorused to control the main burner valve of a gas appliance. The gas appliancehas a pilot burner. A thermopile thermally coupled to said pilot burnerproduces an electrical output which powers the stepper motor and a controlmicroprocessor. The control microprocessor monitors the waveforms of potentialinduced by rotational motion into the unenergized stator coils of the steppermotor. By analyzing the waveforms, the microprocessor can monitor the starttime, stop time, and direction of the rotational motion.