| 摘要 |
PURPOSE:To eliminate the residual vibration based on a load and the like coupled to a rotor and rapidly stop the rotor at a desired stop position by changing a driving voltage to a low voltage when the rotational speed of the rotor of the stepping motor becomes substantially zero. CONSTITUTION:By a starting command, a DC power source 18 of the rated voltage is applied to the stepping motor 11, and a current is caused to flow through stator windings CI-CIV at the set sequence of an operational command logical circuit 22. A rotational speed signal from a tachogenerator 17 is supplied to a threshold detector 21 through an amplifier 20. At the time of shifting to a stop state after intermittent rotation of the stepping motor 11, the rotational speed becomes zero or substantially zero, and at the time of less than the thershold voltage, an operation command logical circuit 22 is operated in accordance with a logic ''1'' signal supplied from a threshold detector 21, and a drive power source 18 is changed over to a low-voltage drive power source 19. |
