High-precision closed-loop gradient magnetoresistive sensor

Abstract

The invention relates to a high-precision closed-loop gradient magnetoresistive sensor. The high-precision closed-loop gradient magnetoresistive sensor comprises eight magnetoresistors, every two magnetoresistors are a pair, the two magnetoresistors in each pair are at the same distance from a measured magnetic source, and the distances between the four pairs of magnetoresistors and the measured magnetic source are different. The two pairs of magnetoresistors closer to the measured magnetic source can detect the magnetic field of the measured magnetic source, and the two pairs of magnetoresistors far away from the measured magnetic source are not interfered by the magnetic field of the measured magnetic source. The two pairs of magnetoresistors that can detect the magnetic field of the measured magnetic source are respectively connected with one pair of magnetoresistors that are not interfered by the magnetic field of the measured magnetic source to form one set of Wheatstone bridge circuits; and the two sets of Wheatstone bridge circuits are respectively connected with two sets of feedback circuits. The high-precision closed-loop gradient magnetoresistive sensor adopts the two sets of Wheatstone bridge circuits and two independent feedback circuits, which can not only measure the magnetic field gradient, but also measure the magnetic field strength. The high-precision closed-loop gradient magnetoresistive sensor is featured by high sensitivity, good linearity, wide temperature range, resistance to external magnetic fields, and high measurement accuracy.

Description

technical field [0001] The invention belongs to the technical field of sensors, and relates to a high-precision, closed-loop gradient magnetoresistance sensor. Background technique [0002] Magnetic sensors are widely used in modern electronic systems to measure physical parameters such as current, position, and direction. At present, the main devices used to measure the magnetic field strength are the following: Hall effect sensors, induction coil magnetometers and fluxgates; Hall effect sensors are sensors designed based on the Hall effect of semiconductors, which are susceptible to interference from external magnetic fields And the temperature drift is large; the induction coil magnetometer works according to Faraday's law of electromagnetic induction, but it cannot detect static or slowly changing magnetic fields, and the low-frequency response is poor. Most of them are used in proximity and distance detection; the basic principle of the fluxgate is Under the excitation...

AI Technical Summary

Problems solved by technology

However, since this technology uses a single bridge circuit, the hysteresis and nonlinear feedback compensation of the sensor itself is not considered, and the measurement accuracy is limited.

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