JPS57122696A - Restoration circuit relating to pulse motor - Google Patents

Abstract

PURPOSE:To enable a simplification of driving circuit and a reduction in power supply circuit by a method wherein the counter electromotive force of a excitation coil is stored in a capacitor while maintaining it above a fixed voltage value, and at the start of the excitation said power is flowed to the excitation coil until it lowers to the fixed voltage. CONSTITUTION:A circuit as illustrated is attached to each phase driving circuit of a pulse motor and the end 1 of the circuit is connected to the grounding side of an excitation coil and the end 7 thereof to the power supply side of the coil. A switch circuit 6 is turned ON or OFF according to the ON or OFF signal of a excitation current received by a signal input section 5. It is so arranged that the circuit is turned OFF as the voltage falls below a fixed level by always keeping the voltage at the point 4 above a fixed level while the signal input section 5 is ON. When from this circuit, a reverse voltage is generated by an OFF action of an excitation crrent of the driving circuit, a counter electromotive force exceeds a fixed level of voltage stored in a capacitor 3 through a diode 2. Then, at the start of the excitation, receiving an ON signal, the signal input section 5 turns ON the switch circuit 6 and the power stored in the capacitor 3 is used for excitation of the corresponding phase.