Voltage Supply System in a vehicle having a Dual-Voltage Power Supply Circuit and Method for Supplying such Power Supply Circuit

Voltage supply system comprises a generator (G) coupled with electrical systems (N1, N2) via a switch (S). The generator and switch are connected to a controller (C) which operates the switch and adjusts the output voltage of the generator depending on the connected electrical systems. An independent claim is also included for a process for supplying electrical systems with a voltage. Preferred Features: The controller is structured to adjust the position of the switch and the output voltage of the generator with respect to the power requirements of the electrical systems, the charge states of energy storage units (B1, B2) and/or the optimization of the fuel consumption.