| 摘要 |
PURPOSE:To reduce the power consumption of a detecting circuit for detecting the rotation or non-rotation of the rotor of a step motor by setting the operation of the detecting circuit at predetermined time of the duration of one period of a commercial power supply. CONSTITUTION:There are provided detection resistors and N gate for switching the resistors at both ends of a drive coil of a step motor to detect the rotation or non- rotation of the step motor. The voltages 8a, 8b generated at both ends of the coil are compared with standard voltage divided via resistors 85, 86 from the voltage of a power supply. The N gate 87 connected in series with the resistors 85, 86 is inserted to prevent a current from flowing through the resistors except when detecting the operation of the motor. These circuits for detecting the rotation or non-rotation of the rotor become operating state only for 20-30msec as a time when the maximum amplitude of one period of the voltage from the commercial power supply is applied thereto to thereby reduce the power consumption thereof. |
