Circuit and method for alternating current motor constructions

Abstract

The present invention relates to a control circuit for a motor, the motor including a rotor having a non-magnetic body portion and a peripheral portion, the peripheral portion being formed on permanently magnetized material, one arcuate portion thereof having north magnetic pole and another arcuate portion having south magnetic pole, a pair of motor coils, a diode bridge circuit having opposed input connections and opposed output connections, a circuit for connecting the respective opposed input connections of the bridge circuit in series with the pair of coils across an alternating current source, a first circuit portion connected across the opposed output connections of the diode bridge circuit including a controllable switch device having a control gate, circuitry to control the voltage applied to the control gate to control the conducting condition thereof and hence current flow through the pair of coils, circuit means including first and second parallel circuits each having a resistor in series with a diode, the first parallel circuit being connected between one of the opposed input connections of the diode bridge rectifier circuit and the second parallel circuit being connected to the other of the opposed input connections of the diode bridge circuit, the outputs of the first and second parallel circuits being connected to the control gate of the controllable switch device, and a Hall Effect device having a connection to the first circuit portion and a connection between the second circuit portion which is controlled by the condition of the Hall Effect device.