An improved piezoelectric energy harvesting circuit for reducing the internal loss

In recent years, piezoelectric energy harvesting (PEH) methods have been intensively investigated. A vibrating piezoelectric device (PD) can generate alternating current (AC) as a consequence of excitation, which needs to be converted into direct current (DC). Due to the high internal resistance and capacitance, it generates low output power through the piezoelectric device (PD) output terminals. A traditional full-bridge rectifier (FBR) converts AC-DC, but it also suffers from power loss due to the forward voltage drop across the diodes. Thus, an improved circuit is proposed to reduce the internal loss of the internal capacitor. As a result, it extracts the maximum output power from the PD. This circuit is capable of a startup with a very low voltage and provides a stable output voltage for powering applications.