Magnetoresistive relaxation oscillator type magnetometer

A magnetoresistive relaxation oscillator type magnetometer, comprising:

• a capacitor, a charging resistor, a discharging resistor, a charge-discharge transfer switch, a high-voltage source terminal, a grounding terminal and a signal output terminal, the charging resistor consisting of at least one charging magnetoresistance unit, and the discharging resistor consisting of at least one discharging magnetoresistance unit;
• wherein
• a first end of the capacitor is connected to the grounding terminal, a second end of the capacitor is respectively connected to the charging resistor, the discharging resistor and the signal output terminal via the charge-discharge transfer switch, and the charge-discharge transfer switch is further connected to the high-voltage source terminal;
• in a charging stage, the charge-discharge transfer switch is switched to the high-voltage source terminal, and the high-voltage source terminal charges the capacitor via the charging resistor;
• while in a discharging stage, the charge-discharge transfer switch is switched to the grounding terminal, so that the capacitor discharges to the grounding terminal via the discharging resistor;
• and
• when an external magnetic field causes resistance change in the charging resistor and the discharging resistor, charge-discharge time of the capacitor is changed, a pulse signal output by the signal output terminal contains one or more harmonic waves of the charging resistor or the discharging resistor, and a signal processing circuit measures the pulse signal to measure the external magnetic field.