JPS55157999A - Stepping motor device system - Google Patents

Abstract

PURPOSE:To improve the rise of coil current and reduce power consumption of a stepping motor through the change-over from the large current let flow in a coil during a short period corresponding to the front edge of stepping-motor driving pulses, to the small current necessary for maintaining running capacity during the remainder pulse period. CONSTITUTION:The transistors of a switch circuit 5 make continuity during the period ranging from the rise to the fall of pulses in accordance with the pulse outputs c and d of a pulse generator 3 so that current flows in a stator coil through a commutator. A pulse generator 4 is triggered by the output pulses of a pulse generator 3 to generate the pulse outputs a and b with a small width at the same cycles as the above-mentioned pulse. The transistors of the switch circuit 6 make continuity during the period ranging from the rise to the fall of the pulses a and b so that current flows in the stator coil through the commutator. The current flowing in the stator coil therefore comes to show such waveforms as denoted by e and f.