Patent ID: 9025300
Filing Date: 2015-05-05
Classification: F23N,G08C

Abstract:
1. A positioner receiving a DC electric signal through a pair of electric wires from a higher-level system to produce its own operating power supply from the DC electric signal that is supplied, and controlling the degree of opening of a regulator valve in accordance with a value of the supplied DC electric signal, comprising: a current inputting-type communication circuit receiving an AC electric signal sent from the higher-level system superimposed on the DC electric signal; and a voltage/current converting circuit, provided in a stage prior to the communication circuit, converting the voltage into an electric current and sending the electric current to the communication circuit if the DC electric signal from the higher-level system is a voltage; wherein the voltage/current converting circuit is provided with an over-current preventing circuit preventing the flow of an electric current higher than a specific electric current value.