DEVELOPMENT OF A POWER MANAGEMENT CIRCUIT FOR MICROENERGY HARVESTERS

Abstract

This work reports on the development a power management circuit (PMC) for micro energy harvesters. The circuit is design to regulate the power between three different power sources for the operation of a wireless sensor nodes (WSNs). The main components of the circuit are resistors (carbon film), capacitors (electrolytic), inductors (ferric bead, axial leaded), and a DC voltage regulators (TPS62100DRC-BRR). The layout of the circuit is patterned on a printed circuit board (PCB) using PCB fabrication technology. To the circuit three different types of sources (DC power source, rectified AC voltage and a solar energy harvester) are connected and the output regulated voltage provided by the PMC is measured and analyzed. At different input voltage levels (0.5 to 5.5 V) the circuit successfully regulated to almost a uniform output voltage (2.75 to 2.96 V). With the circuit using a DC power source and a solar (solar cell) energy harvester a super capacitor is charged to a voltage of 2.75 and 2.05 V in 180 s and 840 s respectively. Beyond 100 Ω load resistance the PMC regulated a constant output current of 180 mA. Moreover, beyond 100 Ω load resistance the power consumption of the circuit is almost steady for different input voltage levels. The average consumption of the developed PMC is about 70 mW.