Efficient Power Management for Energy-Autonomous Wireless Sensor Nodes for Aeronautical Applications

Efficient power management is a key component for energy-autonomous wireless sensor nodes. Thermoelectric energy harvesting is a possible solution for powering such sensor nodes. In this paper, we present a power management circuit that has significant improvements compared with earlier versions. Advancements were made to the rectifier part and the storage controller. The improved rectification circuit is able to control the p-metal-oxide-semiconductor (p-MOS) transistors with a negative instead of zero voltage at the gate. Furthermore, modifications to enhance the total efficiency of the storage controller are applied. The storage controller is a direct current (DC)-DC converter and is controlled by a pulse frequency modulation signal, provided by a microcontroller. In the modified version, the microcontroller is always in low-power mode, and an external circuit is used to control the storage controller. Changes in the software are applied so that the microcontroller is always set in low-power mode. The runtime with and without a load are compared, and the overall self-discharge time is evaluated.