| 摘要 |
PURPOSE:To prevent a DC motor from heating and brushes from deteriorating, by switching the power gain of a power supply circuit to a low gain at initial position setting time. CONSTITUTION:A controller 5 outputs a speed command of direction A, a rotating direction command and a gain switching command, and closes a switch element 8. Thus, a speed deviation signal generator 6 supplies a speed deviation signal through an amplifier 11 to a power supply unit 12. When the projection 1a of a movable member 1 contacts a stopping lever 2, a DC motor 3 becomes a forcibly stopping state. Since the gain of the amplifier 11 drops at this time, a small current flows through the motor 3. When the fact that the motor 3 is in the forcibly stopping state is detected, the motor is moved to the initial position to be positioned. Thus, it can prevent the motor from overheating and brushes from deteriorating. |
