Solar powered low-power sensor module with a radio communication and a user interface

This article presents the power management of a solar powered sensor-module with a RF-transceiver and a user interface. Our platform is the first self sufficient platform, which allows remotely controlled and parameterized measurements by utilizing RF-transceiver technology. A maintenance-free double layer capacitor (DLC) was used for buffering energy to reach uninterrupted operation over day-night periods. Switching power supplies of the pulse-width modulation (PWM) class are used to charge the DLC and to generate stabilized supply-voltages. The regulation circuit for charging during solar-powered operation has been realized with a high-efficiency synchronous step-down converter. To make programmable voltages available, a boost converter has been implemented with the central microcontroller