| 摘要 |
PURPOSE:To accurately control to drive by PID-calculating the current flowing angle of a bidirectional switching element on the basis of a voltage level in response to the real moving speed of a drive unit and a set speed data of a voltage level in response to a binary speed data stored in a memory. CONSTITUTION:After a voltage level detection signal in response to a rotating speed of a rotational shaft of an induction motor 1 from a tachometer generator 7 is rectified by a rectifier 9, it is input to a controller 20. The controller 20 PID-calculates the current flowing angles of the first or second bidirectional switching element 5 or 6 on the basis of the output of the rectifier 9 and set speed data of a voltage level in response to a binary speed data stored in a memory 14. Thus, the elements 5, 6 are controller, power amount supplied to the motor is varied, and a driven unit is controlled at the speed. |
