Experimental study on self-powered synchronized switch harvesting on inductor circuits for multiple piezoelectric plates in acoustic energy harvesting

Self-powering mechanisms for synchronized switch harvesting on inductor circuits have been experimentally investigated to harvest low-frequency acoustic energy (approximate to 200Hz) using multiple lead zirconate titanate piezoelectric plates placed inside a quarter-wavelength straight-tube resonator. Unlike conventional synchronized switch harvesting on inductor circuits, the self-powered synchronized switch harvesting on inductor circuits can perform alternating current/direct current conversion without externally powered switch controllers, which is beneficial in real applications. In the acoustic energy harvester, the nonuniform driving force to piezoelectric plates generates the asynchronous charging effect in piezoelectric internal capacitances. Due to more energy dissipative components in the self-powered synchronized switch harvesting on inductor circuits, there exists a critical voltage above which the self-powered synchronized switch harvesting on inductor circuits outperform the standard circuit. With the incident sound pressure level of 112dB at the frequency of 196Hz, the output power of self-powered series-synchronized switch harvesting on inductor using three piezoelectric plates is measured as 0.796mW. This is 13.2% higher than the standard circuit.