Implementation Battery-less Power Management Circuit for Energy Harvesting System

Abstract

This work presents an alternative solution for extracting energy from micro-power energy converters and facilitates the operation of energy harvester under different loads. In this work, power management circuit is used to give regulated supply to the load. The power management circuit used in this work consists of Voltage doubler, a storage capacitor, trigger circuit and a Boost regulator. Voltage doubler is implemented using p-n junction diodes and used as rectifier for giving DC voltage to storage capacitors. The output of storage capacitors is given to voltage regulator through a trigger circuit. Trigger circuit used in this work is a passive circuit which is normally in open condition and has a single pole single throw function. It also has an analog switch. A Nano-power CMOS control unit drives this analog switch. The trigger circuit is in open condition under normal condition. As the input terminal Voltage reaches to a high threshold value, the circuit changes from open condition to closed state. When voltage at the input terminal becomes less than the lower threshold level then the circuit will again change to open condition. Under closed state, there will be a low resistance path between input terminal and output terminal, whereas under the open condition the input is terminal is disconnected from the output. The Two threshold voltages used are 2.6 V and 1.5V for high and low thresholds respectively. Low Power consumption and very high energy extraction abilities are observed in the experimental results. The designed triggering circuit is employed in a battery-less power management circuit for an energy harvesting system which uses piezoelectric transducers.