Abstract: An optimized extremely-large magnetic field measuring method includes: placing four orthogonally configured tunneling magnetoresistive resistors into an externally applied magnetic field, acquiring the resistances of the tunneling magnetoresistive resistors; calculating the angle between a magnetization direction of a free layer of each tunneling magnetoresistive resistor and that of a reference layer on the basis of the resistances of the four resistors; calculating magnetic field intensity H1 and direction ?1 of the externally applied magnetic field calculating magnetic field intensity H2 and direction ?2 of the externally applied magnetic field; and determining final magnetic field intensity H0 of the externally applied magnetic field on the basis of magnetic field intensity H1 and of magnetic field intensity H2; determining final direction ? of the externally applied magnetic field on the basis of direction ?2 and of direction ?1; and optimizing on the basis of direction ? and of magnetic field intensity

Abstract: A wide magnetic field range measuring method includes the measurement step for a medium-and-large magnetic field and the measurement step for an extremely large magnetic field. In addition to that, the method further includes: Step 1: placing four orthogonally-configured magnetic resistance resistors into an external magnetic field and obtaining the resistance value of each magnetic resistance resistor; Step 2: substituting the resistance values of two mutually orthogonal magnetic resistance resistors into the measurement step for a medium-and-large magnetic field for calculation; if calculation process converges, then, determining that the external magnetic field as a medium-and-large magnetic field with the calculation result representing the magnetic field intensity and the direction of the medium-and-large magnetic field.

Abstract: An all-quadrant measurement method for a middle-large magnetic field includes the steps of placing four orthogonally configured magnetic resistances in an external magnetic field; determining two magnetic resistances with the minimum resistance values, thereby determining that the other two magnetic resistances are in an S1 status, and making resistance values of the two magnetic resistances which are in the S1 status be R1 and R2, and at the same time taking an initial reference layer magnetization direction of the two magnetic resistances as a given reference layer magnetization direction when there is no magnetic field; respectively calculating an included angle between a free layer magnetization direction and the reference layer magnetization direction of the two magnetic resistances; respectively calculating the free layer magnetization direction of the two magnetic resistances; and solving a magnetic field amplitude and direction of the external magnetic field.

Abstract: An all-quadrant measurement method for a middle-large magnetic field includes the steps of placing four orthogonally configured magnetic resistances in an external magnetic field; determining two magnetic resistances with the minimum resistance values, thereby determining that the other two magnetic resistances are in an S1 status, and making resistance values of the two magnetic resistances which are in the S1 status be R1 and R2, and at the same time taking an initial reference layer magnetization direction of the two magnetic resistances as a given reference layer magnetization direction when there is no magnetic field; respectively calculating an included angle between a free layer magnetization direction and the reference layer magnetization direction of the two magnetic resistances; respectively calculating the free layer magnetization direction of the two magnetic resistances; and solving a magnetic field amplitude and direction of the external magnetic field.

Abstract: A wide magnetic field range measuring method includes the measurement step for a medium-and-large magnetic field and the measurement step for an extremely large magnetic field. In addition to that, the method further includes: Step 1: placing four orthogonally-configured magnetic resistance resistors into an external magnetic field and obtaining the resistance value of each magnetic resistance resistor; Step 2: substituting the resistance values of two mutually orthogonal magnetic resistance resistors into the measurement step for a medium-and-large magnetic field for calculation; if calculation process converges, then, determining that the external magnetic field as a medium-and-large magnetic field with the calculation result representing the magnetic field intensity and the direction of the medium-and-large magnetic field.

Abstract: An optimized extremely-large magnetic field measuring method includes: placing four orthogonally configured tunneling magnetoresistive resistors into an externally applied magnetic field, acquiring the resistances of the tunneling magnetoresistive resistors; calculating the angle between a magnetization direction of a free layer of each tunneling magnetoresistive resistor and that of a reference layer on the basis of the resistances of the four resistors; calculating magnetic field intensity H1 and direction ?1 of the externally applied magnetic field; calculating magnetic field intensity H2 and direction ?2 of the externally applied magnetic field; and determining final magnetic field intensity H0 of the externally applied magnetic field on the basis of magnetic field intensity H1 and of magnetic field intensity H2; determining final direction ? of the externally applied magnetic field on the basis of direction ?2 and of direction ?1; and optimizing on the basis of direction ? and of magnetic field intensity

Abstract: A PCB-integrated electromagnetic-induction-principle-based power-line magnetic field energy harvester includes a PCB, the PCB including a substrate and a coil; a rotatable permanent magnet assembly, rotatably embedded in the middle through hole; and a fixed permanent magnet arranged opposite the rotatable permanent magnet assembly and providing the rotatable permanent magnet assembly with a direct current bias magnet field. The PCB-integrated electromagnetic-induction-principle-based power-line magnetic field energy harvester is driven by both of the AC magnetic field generated by the power line and the DC bias magnetic field generated by the fixed permanent magnet. The magnetic field energy around the power line is thus converted into the mechanical energy of the rotatable permanent magnet. The mechanical energy is then converted into the electric energy in the coil. The electric energy is supplied to the following low-power electronic devices (e.g. sensors) in a power transmission system.

Abstract: A giant magnetoresistance current sensor comprises an amorphous alloy magnetic ring having an air gap; a DC magnetic bias coil wound onto the amorphous alloy magnetic ring; a DC constant current source supplying power for the DC magnetic bias coil; a giant magnetoresistance chip disposed in the air gap and having positive and negative outputs; an instrument amplifier having a non-inverting input connected to the positive output of the giant magnetoresistance chip, and an inverting input connected to the negative output of the giant magnetoresistance chip; an operational amplifier having a non-inverting input connected to an output of the instrument amplifier; a voltage following resistance connected between an inverting input and an output of the operational amplifier; an analog to digital converter having an input connected to the output of the operational amplifier; and a digital tube display connected to an output of the analog to digital converter.