Wide Resonance Frequency Control of Magnetostrictive Vibration Power Generator

Abstract

We develop high power magnetostrictive vibration power generator for battery-free wireless electronics. The generator can efficiently extract power from vibration when the device resonates with a frequency of a vibration source, but the power generation amount significantly decreases if it deviates from the resonance frequency. As a solution, it has studied that adjusting resonance frequency by changing electrical loads. In this paper, we investigated design of generator’s coil for wide resonance frequency adjustment by electric control. In experiment, we made prototypes with a different coil and connected a capacitor to control resonant frequency. Then we measured the change in resonant frequency of the generator by changing capacitance. In the result, we found that the coil design to strengthen the coupling between the electrical part and the mechanical part while keeping the internal resistance small was necessary to widen the resonance frequency adjustment width.