| 摘要 |
PURPOSE:To perform automatic control for fine pressure adjustment by coupling a motor with a screw lever through a gear, generating and inputting pulses to the driver for the motor in acocrdance with the number of revolutions of the screw lever, and bringing its drive under programmed control. CONSTITUTION:A reversible motor 42 is driven to rotate a screw lever 32. This rotation is transduced by a transducer 48 into a pulse signal, which is inputted to a motor driver. When the number of the pulses reaches a set value, the motor 42 is stopped and the screw lever 32 is rotated at a necessary rotational angle. This rotation contracts a spring 40 to transfer necessary elastic force to a diaphragm 24, whose secondary pressure balances with said elastic force. The secondary pressure is controlled in proportion to the rotational frequency of the screw lever 32. Therefore, an increase and decrease in secondary pressure are controlled automatically and accurately by simple programming. |
