| 摘要 |
PURPOSE:To prevent a cycling phenomenon, by lowering the control gain of a servomechanism in accordance with a state of a deviation output. CONSTITUTION:A controlled variable signal from a sensor is applied to a terminal 18. A circuit 19 detects a state that a controlled variable is varied in the direction being apart from a set value, and generates a high level signal when it is in the approaching direction. When an output of the circuit 19 is in a high level, an output of an inverting circuit 29 is in a low level, and an FET33 is turned off. Therefore, an output of a comparing circuit 13 is provided to a motor 16 through a servo-amplifier 15. When an output of the circuit 19 becomes a low level, that is to say, the controlled variable is varied int the direction being apart from the set value, an output of the inverting circuit 29 becomes a low level, and the FET33 conducts. Accordingly, the input side of the servo-amplifier 15 is grounded, and driving of the motor 16 is stopped. |
