MAGNETIC FIELD TYPE CURRENT SENSOR

摘要

PROBLEM TO BE SOLVED: To provide a magnetic field type current sensor suppressing the power consumption of an exciting circuit and an inverse exciting circuit and reduced in power and size. SOLUTION: An exciting coil 7, a measuring detection coil 6 and an inverse exciting coil 8 are wound around a measuring core 2 and the measuring conductor 4 inserted into the measuring core 2 is equipped with bypass conductors 13 and two conductors are made of the same non-magnetic material (high purity copper) and the bypass conductors 13 are arranged around the measuring conductor 4 by regarding the conductor 4 as a shaft. Since two conductors are same and non-magnetic, they are same in resistance-temperature characteristics and the resistance ratio of two conductors is not changed and a non-measuring current can be accurately measured. Since the bypass conductors 13 are arranged around the measuring conductor 4, the interference with an external electric field is prevented to enable stable measurement. Further, the current allowed to flow to the exciting coil 7 and the inverse exciting coil 8 can be reduced.