| 摘要 |
PURPOSE: To prevent unnecessary power consumption and motor drive noise generated at the time of AC switching and phase switching in the speed controller of an AC motor for changing the drive voltage of the AC motor in multiple stages by the capacitance control of a capacitor. CONSTITUTION: This speed controller is provided with a large number of capacitors C1 -C5 , respectively serially connected to a motor 10 and a large number of switching elements TC1 -TC5 for respectively switching an AC power supply voltage supplied to the motor 10 through the respective capacitors C1 -C5 . The capacitances of the capacitors C1 -C5 are set so as to be different from each other, and thus by varying the AC power supply voltage which is supplied to the motor 10 through the respective capacitors C1 -C5 , the speed of the motor 10 is controlled in multiple stages. |
