Working Principle

When the input signal rises, the air supply solenoid valve 1 turns ON, and the exhaust solenoid valve 2 turns OFF. Therefore, supply pressure passes through the air supply solenoid valve 1 and is applied to the pilot chamber 3. The pressure in the pilot chamber 3 increases and operates on the upper surface of the diaphragm 4.

As a result, the air supply valve 5 linked to the diaphragm 4 opens, and a portion of the supply pressure becomes output pressure.

This output pressure feeds back to the control circuit 8 via the pressure sensor 7. Here, a correct operation functions until the output pressure is proportional to the input signal, making it possible to always obtain output pressure proportional to the input signal.