| 摘要 |
PROBLEM TO BE SOLVED: To provide a controller suitable for an induction motor as a power source of an elevator or the like. SOLUTION: A counter 17, a comparator 18 and a switching unit 19 are added to a conventional controller. When an operating time of the induction motor 3 is long, a function for free running the motor 3 by cutting off an output of a voltage type inverter 2 is imparted when an operation command of the motor 3 is dropped. |
