An Experimental Verification for Improvement of Output Characteristics by LC Resonance in Vibration Generators with Boost-type Current-Improving Passive Rectifier

Recently, the energy harvesting is attracted attention. Energy source is everywhere around us: mechanical vibration, stress, and strain, waste heat, sun light or room light, electromagnetic ray, chemical or biological sources, and so on. Vibration generators based on piezoelectric elements have been highlighted as low-power sources. As the vibration generators provide very low power around mW or μW level, the improvement of its performance is required in order to use the power. This paper investigates the improvement of the output characteristics by using passive devices. The proposed circuit consists of parallel inductor and capacitor for LC resonance and the boost-type current-improving passive rectifier. The LC resonance equivalently reduces the internal capacitor of piezoelectric elements. As a result, the output voltage and power grows up compared to conventional circuit. The validity of the proposed circuit is experimentally verified in this paper.