| 摘要 |
PURPOSE:To cut down the power consumption by a method wherein the frequency is divided into high and low values to open and close a power supply at low frequency when the excitation winding of a stepping motor is excited at high frequency while the power supply is opened and closed at high frequency when the excitation winding is excited at low frequency. CONSTITUTION:The output (a) from a reference voltage oscillating circuit 29 is frequency-divided to generate rectangular waves in frequency of b>c>d for selecting high frequency numbers in the inverse order by interlocking switches 31A, 31B. A wave form taking circuit 33 outputs signals e, f and g, h in inverse phases with one another to open and close transistors 38-41 for making a motor 28 step using excitation coils 28A, 28B. A switch 31A selects the frequency in the inverse high low frequency to that of another switch 31B to open and close Trs 24, 22 for feeding power to the excitation coils 28A, 28B through the intermediary of a reactor 25. When the motor 28 is driven at high speed, the transistors 24, 25 are opened and closed at low speed to reduce the voltage decline in the reactor 25 for lowering the excitation voltage while when the motor 28 is driven at low speed, the excitation voltage is also lowered. Through these procedures, the power consumption can be cut down. |
