Patent ID: 8229600

Claim:
A flow controlling device comprising a flow path wherein a fluid flows, a solenoid valve for adjusting the degree of opening of the flow path, a valve driving circuit for driving the solenoid valve, a flow rate measuring device measuring a flow rate of the fluid that flows in the flow path, and a controlling device applying instruction signals to the valve driving circuit so as to cause the flow rate to match a setting value, and which operates having received a power supply supplied from the outside, comprising: an analog inputting circuit converting one of an inputted analog voltage value or analog electric current value, as a setting value, into one of a specific digital value or analog value, a controlling device outputting a command signal based on the measured flow rate and the one of the digital signal or analog signal transmitted from the analog inputting circuit; a signal transmitting device isolating electrically the controlling device and the valve driving circuit and transmitting the instruction signal from the controlling device to the valve driving circuit; an isolating power supply circuit isolating electrically the analog inputting circuit and the controlling device from the valve driving circuit, and supplying power to the analog inputting circuit and the controlling device; and a non-isolating power supply circuit supplying power to the valve driving circuit.