| 摘要 |
PURPOSE:To drive a step motor under an optimal condition, by changing the width of driving pulses depending on the variation in the voltage of power. CONSTITUTION:When a clock signal is applied to an input terminal Vin, a field- effect transistor FET2 is turned on the another field-effect transistor FET3 is turned off and a capacitor C2 is quickly charged to the voltage VDD of power. When the potential of the clock signal becomes low the field-effect transistor FET2 is turned off and the other one FET3 is turned on and the capacitor C2 is discharged through the latter transistor FET3. When the terminal voltage of the capacitor C2 falls to a half of the power voltage VDD, the action of an inverter INV is switched over and an output pulse of width corresponding to the power voltage VDD appears on an output terminal Vout. The output oulse pulse is applied to the step motor. |
