NON-CONTACT DC CURRENT SENSOR AND DC CURRENT MEASURING SYSTEM USING NON-CONTACT DC CURRENT SENSOR

摘要

PROBLEM TO BE SOLVED: To provide a non-contact DC current sensor capable of accurately measuring a DC current flowing in an electric wire in a wide range from a small current to a large current.;SOLUTION: A DC current sensor for measuring, without contacting, a DC current flowing in an electric wire as a measurement object is disclosed. The DC current sensor has an AC closed circuit constituted of a toroidal coil consisting of a core made of an approximately annular magnetic material surrounding the electric wire and a conductor wound around the core, an AC excitation circuit causing an AC excitation current to flow to one end of the toroidal coil, and a resistor connected between the other end of the toroidal coil and the ground and generates an AC voltage corresponding to the DC current flowing in the electric wire, between both ends of the resistor. The AC voltage generated between both ends of the resistor is converted to a DC current value of the DC current flowing in the electric wire, through a conversion circuit, and the DC current value is displayed on a display unit.;SELECTED DRAWING: Figure 3;COPYRIGHT: (C)2017,JPO&INPIT