Design of magnetic field alarm powered by magnetic energy harvesting

This paper presents a design of magnetic field alarm powered by magnetic energy harvesting. It consists of an energy harvesting module, Cockcroft-walton circuit and piezo buzzer. The energy harvesting module is composed of coil and magnetic flux concentration core. It can generate 200 μW from an environmental magnetic field of 200 μT at 60 Hz. The Cockcroft-walton circuit can converts the ac voltage to a suitable dc voltage for the piezo buzzer. This alarm can notice not only the magnetic field level defined by ICNIRP2010 but also the existence of magnetic field energy to be harvested. It is the first demonstration of a “self-generating component” powered by magnetic energy harvesting.