Smc Kabushiki Kaisha

Tadao Watanabe

Yuji Tsuda

Atsushi Fujiwara

Disclosed is a pressure control apparatus comprising an air-supplying solenoid-operated valve and an air-discharging solenoid-operated valve which are composed of normally closed type solenoid-operated valves respectively, a power source-monitoring circuit for detecting whether or not a power supply source is dropped to be lower than a predetermined value, a power source-compensating circuit for delaying drop of a solenoid-operated valve-driving power source for driving the air-discharging solenoid-operated valve when the power supply source is dropped, and a control circuit for deriving an OFF signal to the air-supplying solenoid-operated valve and deriving an ON signal to the air-discharging solenoid-operated valve when the power supply source is dropped.

Pressure control apparatus

An electropneumatic regulator system, which has an electropneumatic regulator for controlling a pressure and a flow rate of a fluid supplied from a fluid source on the basis of a level of an input signal, comprises a communication unit for making communication with a master station, and a control unit for controlling the electropneumatic regulator in response to at least the contents of communication data received by the communication unit. Accordingly, it is possible to collectively control one or more electropneumatic regulators by using, for example, the master station on the basis of the communication so that the response performance can be improved for the remote control of the electropneumatic regulators, and the cost can be reduced.

Electropneumatic regulator system

An analog voltage signal V.sub.A generated from a command signal generating device is converted to a PWM signal V.sub.B by a converter, and a drive transistor is ON/OFF controlled by the PWM signal V.sub.B, whereby a current is conducted to a heater. When the heater is heated, a fluid filling a chamber of the valve device is caused to expand, whereby a membrane approaches a nozzle and a flow amount of pressurized air introduced to the valve device is restricted. As a result, energy consumed by the drive transistor is reduced and energy efficiency is improved. Further, because the generated heat from the drive transistor is small, the fluid is not affected thereby and raised in temperature by the transistor heat, whereby the flow amount characteristics of the valve device can be controlled in a stable fashion.

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Ibaraki-ken, Japan

Tadao Watanabe