With a total weight of 1kg and an approximate volume of 1000 cc, Swayam satellite demanded an innovative approach at every design phase, from screening of components in order to fit the stringent mass budget to selection of suitable electronic devices which honoured the mere 2W of power produced by the solar panels.
The power system of Swayam is a completely autonomous, dedicated to providing uninterrupted DC power to the entire satellite during all times. At the heart of power system, there is a Li-ion battery pack consisting of 4 cells arranged in parallel combination. The satellite generates power from 12 solar cells arranged in a 2s-6p configuration. Each face of the satellite has two solar cells mounted on them. The Power system is a self-initiating system, and is the first system to start after launch. The system is dedicated to providing power to all the electrical systems on board the satellite and protects them from electrical faults like over current, under voltage and over voltage. One of the primary tasks of power system involves generation of a stable 3.3V bus form the battery using a DC-DC converter. This bus provides uninterrupted and regulated DC power to various loads in the satellite. Power system is also directly responsible for antenna deployment which is achieved by sending a surge of current on the command of the two on-board microcontrollers. Power system includes multiple current, voltage and temperature sensors which provide the critical health monitoring data which can be downlinked on request.