The Capacitor Reusing Technique for the Synchronous Switch Harvesting on Capacitor Circuits in the Piezoelectric Energy Harvesters

This paper describes a capacitor reuse technique for Synchronous Switch Harvesting on Capacitor (SSHC) circuits in Piezoelectric Energy Harvesters(PEH). The PEH is a technology that utilizes piezoelectric transducers to convert mechanical vibration energy into electrical energy. In this material, the parasitic capacitance causes power loss. The SSHC is one of the improvement techniques, based on a switched-capacitor circuit. However, a large capacitance or using SSHC in multiple stages was often required for effective charge inversion. In the proposed circuit, reusing capacitors allows for two capacitors and additional switches to achieve an efficiency comparable to that of a three-stage SSHC in the conventional design. Simulation results indicated that the proposed technique can improve the Voltage Flipping Efficiency (VFE) by approximately 5% to 8.3% compared to conventional SSHC circuits.