| 摘要 |
PURPOSE:To obtain such damping device as is simple, cheap and high in damping force by providing a damping circuit through which to reverse the direction in which an AC capacitor is connected after detaching a power supply. CONSTITUTION:An arrangement is such that switches 21-24 are closed and switches 25, 26 are opened at normal operation, and switches 21-24 are opened and switches 25, 26 are closed at damping, thus a connection of capacitors 27, 28 coming in the direction counter to the operating state. When the switches 21, 22 are opened, a current according to a speed electromotive force flows to a rotor winding by the sum of a magnetic flux by discharging current of the capacitors 27, 28 and a residual magnetic flux after the switches 21, 22 turn off, and a damping torque opposed to the running direction works on the rotor according to the current and the magnetic flux, thus damping an induction motor 30. |
