| 摘要 |
PURPOSE:To prevent the step-out of a motor caused by insufficient torque, and at the same time, to shorten the control time caused by positioning by varying the frequency of a driving pulse signal in accordance with the voltage of a battery. CONSTITUTION:The voltage dividing of the voltage of a battery 1 is made at resistance R2 and R3, and the divided voltage is supplied to a non-inversional input terminal of a comparator 2 and an inversional input terminal of a comparator 3 as the detection voltage Vm detecting the supply voltage. CPU 4 is so designed that the high, medium and low of supply voltage is decided by the output of the comparators 2 and 3, the high speed of pulse frequency is selected in case of high, the medium speed of pulse frequency is selected in case of medium, and the low speed of pulse frequency is selected in case of low. According to the constitution, a steeping motor 6 is driven by a driver 5 with the selected frequency after completing the selection of pulse frequency. |
