Self-start piezoelectric energy harvesting circuit with adjustable uvlo converter for wireless sensor network

Abstract

This paper proposes a self-start piezoelectric energy harvesting circuit with an undervoltage-lockout (UVLO) converter for a wireless sensor network (WSN). First, a selfstart circuit with mini piezoelectric energy harvester (PEH) is designed to supply the power for operation of the oscillator without battery. The experimental results show that a batteryless self-start circuit successfully operates the oscillator with mini-PEH, and self-starting time is 0.45 s. Second, this paper proposes an adjustable UVLO converter that can supply the power even if a power consumption of a wireless sensor node is higher than generated power from PEH. The experimental result shows the adjustable UVLO converter supplies 45 mW for 0.12 s after charging the output power of an impedance matching circuit (1.7 mW) for 10 s. This paper shows that the proposed circuit successfully overcomes challenging issues - self-start and lower power generation - for powering WSN.