Signal detection circuit of magnetic-flux-gate magnetometer, and the magnetic-flux-gate magnetometer

Abstract

The invention relates to the technical field of seismic, and discloses a signal detection circuit of a magnetic-flux-gate magnetometer, and the magnetic-flux-gate magnetometer. The signal detection circuit includes a signal channel and an excitation channel, wherein the signal channel acquires a magnetic field signal from a sensing probe; the excitation channel outputs an excitation signal to the sensing probe; the signal channel includes successively connected probe input circuit, frequency selection amplification circuit, phase sensitive detection circuit, integrating circuit and feedback circuit; the feedback circuit comprises a first feedback path and a second feedback path; the first feedback path is configured as a linear feedback circuit; the second feedback path is connected with the first feedback path in parallel, and is configured as a non-linear feedback circuit; and the second feedback path works when the magnetic field signal detected by the sensing probe reaches the relative maximum measuring range for observation. The signal detection circuit of a magnetic-flux-gate magnetometer utilizes the non-linear negative feedback method, and converts different feedback branches when a small signal is input and when a large signal is input, thus solving the problem that a traditional signal detection circuit cannot give consideration to both the resolution of the signal and allowance of input of the large signal.

Description

technical field [0001] The invention relates to the technical field of earthquakes, in particular to a signal detection circuit of a fluxgate magnetometer and the fluxgate magnetometer. Background technique [0002] Geomagnetic signals carry non-rich geophysical information, so geomagnetic observation is an important observation method of the China Earthquake Precursor Network, and the fluxgate magnetometer is the most important observation instrument. Fluxgate magnetometer is a vector-type sensitive sensor used to measure DC magnetic field or low-frequency magnetic field. It is the most widely used instrument for measuring quasi-static and slowly changing vector magnetic fields, and it is also the most precise vector-type magnetic field sensor at room temperature. It can accurately measure the strength and direction of the geomagnetic field, and has the advantages of low noise, high resolution, good temperature stability, wide measurement range, weak magnetic measurement, l...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a signal detection circuit of a fluxgate magnetometer and the fluxgate magnetometer, which are used to solve the problem that the signal detection circuit of the existing fluxgate magnetometer cannot ensure both the resolution of the signal and the allowable large signal input problem

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