The power supply (p box)

The box P, has the function of electrically connecting the satellite with its various subsystems. The primary tension comes from the solar panels, and it is nominally 27 V (between 24 and 34 V). Starting from this, the box P provides three different tensions, two for the analog part (+6V, -6V) and one for the digital (+5V), totally independent.

Figure 1 The ignition of P box and so NINA switching ON is realized by telecommand. For redundancy reasons, there are two independent systems of secondary power-supply, again selected by telecommand. The status of the box P during the flight is monitored by 8 signals (4 for any of the two power-supply systems), that take under control currents and temperatures inside the box.

A sketch of the power supply distribution inside the instrument is shown in Figure 1.