Structure and working principle of indium antimonide current sensor

The following is a circuit diagram of [Structure and Working Principle of Indium Bismuth Current Sensor]

Structure and working principle of indium antimonide current sensor

An inductive magnetic head made of an indium antimonide-indium eutectic thin film magnetoresistive element made of MRCS (Fig. 1) is mainly composed of a wire, an insulating substrate, InSb-In magnetoresistive elements MR1 ​​and MR2, a permanent magnet, and five pins. In addition, a metal casing for shielding and protection is added. MR1 and MR2 are a pair of magnetoresistive elements placed opposite each other with approximately equal resistance, and the wires are placed at the symmetry axis positions of MR1 and MR2. Its equivalent circuit is shown in Figure 1(b).

The InSb-In magnetoresistor is the core of the sensor and its working mechanism is based on the magnetoresistance effect. According to the magnetoresistance effect, the resistivity changes to

Where: B is the magnetic induction; ρB and ρ0 are the resistivity of the InSb-In magnetoresistor when there is a magnetic field and no magnetic field, respectively; μn is the mobility of the carrier. The magnetoresistance of this InSb-In eutectic thin film magnetoresistor still conforms to the law of InSb single crystal. It is a parabolic shape curve and can be expressed as a quadratic trinomial.

RB/R0=1+αB+βB2 (2)

Where: B is the magnetic induction; RB and R0 are the resistance values ​​of the InSb-In magnetoresistor when there is a magnetic field and no magnetic field, respectively; α, β are the coefficients related to the component. When the wire has an alternating current, an alternating helical magnetic field is generated around it, and an alternating voltage signal is generated at the intermediate point of the connection, and then amplified and compared to achieve an alternating current. monitor.

(Editor: Circuit Diagram)