Enhancement of the conversion efficiency in an energy harvester from vibrations

The paper presents some theoretical and experimental aspects concerning the efficiency enhancement for conversion of kinetic energy harvested from the environment into electrical energy supplied as output voltage of an electromagnetic generator with permanent magnets. After a theoretical characterization of the generator, an analysis of the magnetic force and magnetic field produced by the system is performed, followed by a numerical and experimental determination of the generated voltage. In order to maximize the induced voltage, ferromagnetic discs of different thicknesses, placed on the ends of the mobile magnet, were used, resulting in a significant voltage increase. Experimental results were close to those obtained in simulations.