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.