MAGNETIC CURRENT SENSOR AND CURRENT MEASUREMENT METHOD

摘要

A magnetic current sensor including a Wheatstone bridge circuit formed of four magnetoresistance devices; bias magnetic field application that applies a bias magnetic field to the magnetoresistance devices; and air-core coils provided on both sides of the Wheatstone bridge circuit. The Wheatstone bridge circuit generates a voltage corresponding to an induction magnetic field generated by a current to be measured flowing through the air-core coils. According to the magnetic current sensor and current measurement method, the linearity between a current and an output voltage is near 0 mA as a result of magnetic hysteresis being suppressed, and an increase in current and a reduction in size and cost are realized as a result of insulation between the current circuit side and the MR device side being excellent.

主权项

1. A magnetic current sensor comprising:
a Wheatstone bridge circuit including four magnetoresistance (MR) devices; a pair of magnets with respective opposing poles facing each with the Wheatstone bridge circuit disposed therebetween, such that the pair of magnets apply a bias magnetic field to the MR devices; and air-core coils disposed on respective opposing sides of the Wheatstone bridge circuit, wherein the Wheatstone bridge circuit generates a voltage corresponding to an induction magnetic field generated by a current flowing through the air-core coils.