| 摘要 |
PURPOSE:To improve an efficiency without sacrificing the propriety of controllability by conducting a stepping motor in a state of highest efficiency in a phase relationship between a rotor and a stator. CONSTITUTION:A signal M concerning a rotor position is input from a position detector 15 to a sample-holding circuit 25 through a sampling pulse generator 24. If the phase of a rotor 3 is advanced from the maximum efficiency point, a sample-holding voltage becomes a reference voltage Vref or less, while if it is delayed from the maximum efficiency point, it becomes the voltage Vref or more. Accordingly, after the difference between the sample-holding voltage and the reference voltage Vref is amplified by a comparing/amplifier 26, then clamped, and fed to a driving circuit 18 through a limiter 28. The control efficiency of a stepping motor 2 is enhanced under such control. |
