| 摘要 |
PURPOSE:To improve a starting property, by keeping a phase compensation circuit disconnected from a servo system in starting and by connecting the compensation circuit to the servo system simultaneously with the time when a constant speed is reached. CONSTITUTION:The speed of a motor 3 is detected by a detector 9. A detection signal from the detector is changed by an f-V converter 10 into a voltage proportional to the speed. The voltage is compared with a reference voltage 11 by a voltage comparison amplifier 12. The difference between both the voltages is amplified by the amplifier. A pulse amplitude control circuit 13 is regulated by the amplified signal to control the speed. A switch circuit 20 is operated simultaneously with the closing of a power switch 17 to ground the output of a relay driving circuit 18 and cut off the exciting current of a relay switch 21. The motor 3 is accelerated as the relay switch 21 is open, namely, as a phase compensation circuit comprising a resistor 15 and a capacitor 16 is disconnected from a servo system. When a motor 3 goes into the vicinity of a constant speed, the switch circuit 20 is opened by a time constant circuit 19 and the relay switch 21 is short-circuited by the driving circuit 18 to connect the phase compensation circuit to the servo system. |
