| 摘要 |
PURPOSE:To enable to operate an induction motor from an extremely low speed by flowing a DC or a pulsating current in the prescribed direction for the prescribed time in the prescribed sequence to coils of the stator of the motor and varying a resultant magnetic field of a space having a rotor in the stator. CONSTITUTION:A DC or a pulsating current of a power source 16 made of a transformer 12 and a rectifier 14 is supplied through contacts R1-R6 of switching means 18 to connecting points (a), (b), (c) of coils A, B, C of the stator of an induction motor 10. Relays R1-R6 are driven by a sequence controller 20, currents of the prescribed amplitude are flowed in the prescribed direction for the prescribed time in the prescribed sequence to the coils A, B, C, or stopped, thereby varying intermittently a resultant magnetic field inside the stator to rotate a rotor. Accordingly, the motor 10 can be operated from extremely low speed to the vicinity of the rated speed in a wide range by the repetition of switch means 18. |
