| 摘要 |
PURPOSE:To simplify the constitution of circuits and eliminate false operation due to noises by controlling the signal of a deviation detecting means by taking the signal of a high-speed operation area detecting means into a thinned-out control means within the braking area of the induction motor. CONSTITUTION:In the electromotive are of the motor 1, a speed instruction 12 and a signal from a speed detecting means 9 are detected by the deviation detecting means 13 and a power control means 2 is controlled through the intermediary of phase shifting means 19 and 20, whereby the primary voltage control is performed. In the braking area, a signal from a synchronous signal generating means 17 is delivered as a timing signal in accordance with the signals of the deviation detecting means 13 and 14 by a phase shifting means 30, while a signal from the high-speed operation area detecting means 16 is taken in and the deviation signal of the deviation detecting means 14 given to the phase shifting means 30 by the thinned-out control means 31 is thereby controlled. Accordingly, the constitution of circuits can be simplified, whereby the false operation caused by the noises breaking into a digital circuit can surely be prevented. |
