| 摘要 |
PURPOSE:To enable to accurately position to stop a stepping motor by applying the output of an amplitude detector for detecting the vibrating amplitude of a rotor to a comparator, and decreasing the reference voltage to a power down voltage after sufficiently converging the vibration. CONSTITUTION:The voltage of a reference voltage generator 13 and the output of a detector 13 for detecting the currents of motor coils 5-8 are applied to a differential amplifier 12, and a semiconductor switch 9 for supplying the constant current is controlled to be opened or closed. A position detector 22 for detecting the amplitude of the rotor and an amplitude detector 21 for detecting the amplitude of the vibration are provided, the output and the output of a reference amplitude voltage generator 20 for outputting the voltage after the time for converging the vibration of the motor are compared by a comparator 19, a power down circuit 14 is operated, and the reference voltage of the detector 13 is reduced to the power down voltage. Accordingly, accurate stopping positioning can be performed with a low voltage, and the heat generation of the coil can be reduced. |
