Synchronized charge extraction circuit for electret‐based vibration energy harvester

Impedance matching is one outstanding issue for the electret‐based vibration energy harvester (eVEH) due to its small equivalent capacitance. In this paper, the authors developed a synchronized charge extraction (SCE) circuit for eVEH, to improve its performance in small load resistance conditions. An electromagnetic detector is embedded with the eVEH to detect its maximum vibration amplitude. The synchronized switch is controlled by a microcontroller unit. According to the authors’ simulation study, the power output of eVEH interfaced with the SCE circuit is three times larger than that of the standard circuit, which proved the effectiveness of our SCE circuit.