The SXC-PSU-03 power supply system controls the satellite’s power from the SXC-BAT-03 battery pack and solar panels (usually SXC-SSS-03, SXC-SSE-03, SXC-SGS-03, or SXC-SGE-03), which can be connected in an amount of up to 14 pieces. The contact for charging external batteries is located on the PC104 connector and, as a rule, connects to the USB connector of the SXC-SP-03 service panel. A special interface is used to exchange data with the battery pack.
The power supply system allows the use of solar panels with built-in electromagnetic coils. On the power supply board there are three input connectors for solar panels, one connector per satellite axis. The solar panels of each axis are interconnected by a cable system and are connected to a separate connector. This allows you to build up the coils built into each solar panel to sum their magnetic fields. Coils are connected to the drivers through the PC104 connector. Chargers use the maximum power point tracking algorithm (MPPT, charging end) and support two types of photocells: GaAs and Si, provided that the voltage level is correct.
The power supply system includes a 4-channel output power switch with protection for current and voltage and the formation of telemetry for each channel. The general telemetry of the power supply system is transmitted via the CAN bus and contains information on the condition of the batteries, input power, temperature and the type of faults detected. In addition to the four built-in output channels of the switch, there are 3 external signals for controlling the auxiliary power switch, which can separately activate sensors, including solar, and an on-board computer.
The power supply system protects the batteries with built-in temperature sensors, heaters and switches, so that the power supply operates in the temperature range 40 … + 85 ° C. It is recommended that a preliminary calculation of temperature conditions be made for each flight.
The hardware watchdog timer is configured to work with a period of 25 hours and can only be reset by a command from the flight control center. This eliminates the looping of the control system software. Several software watchdog timers are also used, which act as the supervisor of the software functions.
Reliability of the software is provided by a fault-tolerant memory access configuration and the presence of a built-in loader of software updates during the flight.