Design of power conditioning circuit for thermal energy harvester in powering a wireless sensor node

Abstract

Wireless Sensor Network (WSN) comprises of huge quantity of miniature sensor nodes (SNs) with certain limitation of computer resources which capable for sensing, gathering, data processing and wireless communication. Since most of the SNs are powered by traditional batteries, it can be inconvenient due to their limited lifespan. In this paper, a thermoelectric generator (TEG) is used as thermal energy harvester with the intention to extend the SN lifespan. Since the output voltage generated by this TEG is insufficient to power up the node, a DC-DC step-up converter circuit based on MAX757 integrated circuit is designed to step up the output voltage produced from TEG up to 3V. The SN required an average power which is about 25mW in the active mode and 60µW when it is in sleeping mode. This node can transmit data whenever there is at least a temperature gradient of 15? between the hot and cold surface of TEG.