An efficient power supply for Wireless Sensor Networks through environmental energy harvesting

Recently, Wireless Sensor Networks (WSNs) have been widespread utilized in automation. The power supply of WSNs has significant influences on their performance. This paper presents a novel power management circuit for WSNs. The proposed circuit provides an interminable energy source for wireless sensor nodes through environmental energy harvesting. The energy harvester is comprised of a thermoelectric generator and an autonomous step-up DC-DC converter. The proposed converter has two stages: the first is an amended oscillator which provides an AC voltage for the second stage and the second stage is an AC-DC voltage multiplier. The proposed converter is simulated and also fabricated. Simulation and experimental results show that this converter has a relatively high step-up ratio at low input voltages, 11.6 for a 0.5V input voltage. Furthermore, its best efficiency is as high as 70% while delivering ultralow powers as low as 66μW to a wireless sensor node.