MAGNETIC COMPENSATION CIRCUIT AND METHOD FOR COMPENSATING OUTPUT OF MAGNETIC SENSOR, RESPONDING TO CHANGES OF FIRST MAGNETIC FIELD Russian patent published in 2018 - IPC G01R33/00 

FIELD: measurement.

SUBSTANCE: invention relates to the measurement of magnetic fields, and in particular to methods and devices for accurately detecting the presence of a weak scattered magnetic field in the presence of a known stronger field. Additive magnetic compensation circuit, comprising a sensor unit which outputs a first digital signal, and a controller that receives said first digital signal, computes a digital compensation signal, and then sends said digital compensation signal to said sensor unit. Sensor unit comprises: a magnetic sensor which creates a first analogue signal by sensing a component of the magnetic field; an adder that receives the first analogue signal and outputs a second analogue signal; an ADC which converts said second analogue signal to said first digital signal, and a DAC which converts said digital compensation signal to a third analogue signal for input to the adder. Said additive magnetic compensation circuit comprises a computer that generates a digitally predicted model of the magnetic field, wherein the controller imports the first digital signal and the digitally predicted model of the magnetic field and outputs the digital compensating signal to said compensation circuit.

EFFECT: technical result is to suppress the effect of a strong external magnetic field on the magnetic sensor.

17 cl, 6 dwg