JPS5646695A - Circuit for exciting pulse motor - Google Patents

Abstract

PURPOSE:To prevent transient oscillation of a pulse motor at rise and fall times by applying under control a pulse train sequentially increasing the buty ratio at the time of rising an exciting pattern and a pulse train sequentially decreasing the duty ration at the time of falling the pattern. CONSTITUTION:An n-digit ring counter 1 is porvided, which produces first pulse train sequentially increasing a duty ratio and second pulse train sequentially the duty ration and applies them to a control circuit 4. The control circuit 4 detects exciting pattern corresponding to an exciting current supplied to a pulse motor 7, outputs the first pulse drain at the time of rising the pattern and the second pulse train at the time of falling the pattern. The control circuit 4 thus controls through a modulating circuit 5 and a driving circuit 6 the motor 7. Accordingly, the oscillation of the motor at the time of rising and falling can be prevented by an open loop control, thereby improving the power efficiency with simple circuit.