A Novel Rectifier-Less Synchronous Electric Charge Extraction and Inversion Interface Circuit for PE Energy Harvesters

A novel rectifier-less synchronous electric charge extraction and inversion (ReL-SECEI) interface circuit for Piezoelectric energy harvesters is proposed in this article. At the peak voltages of the Piezoelectric Transducer (PZT), a portion of electric charges is inverted on the clamped capacitance
C
_p
, so that the PZT is automatically regulated at a higher output voltage state to improve extracted energy from the PZT. In addition, the self-powered implementation of the ReL-SECEI circuit is presented. It reduces the number of components by optimizing the positive and negative synchronous switches. The rectifier-less and simplified designs reduce the internal power loss and, hence, improve the energy harvesting efficiency. The ReL-SECEI circuit is verified by the experiment, the harvested power is load-dependent and the peak output power is obtained with the optimum load, which reaches 4.2 times that of the standard energy harvesting circuit.