A circuit arrangement (1) for power distribution in a motor vehicle is described, which comprises a transformer(T 1, T 1a..T 1n )having at least three transformer windings(W 1, W 1a..W 1n, W 2, W 2a..W 2n, W 3, W 3a..W 3n ). A first and second on- board supply inside the vehicle and a power supply which is outside the vehicle can be connected to the circuit arrangement (1), which supplies are coupled via the transformer windings (W 1, W 1a..W 1n, W 2, W 2a..W 2n, W 3, W 3a..W 3n ) and converters(UR 1, UR 2, UR 2a..UR 2n, UR 3, UR 3a..UR 3n ). The third converter (UR 3, UR 3a..UR 3n ) can be connected via a first change-over switch(US 1, US 1 ')alternatively to the first on- board supply inside the vehicle or to the power supply outside the vehicle. Aplurality of first converters(UR 1 ) and/or a plurality of secondconverters(UR 2, UR 2a..UR 2n ) and/or a plurality of thirdconverters(UR 3, UR 3a..UR 3n )each being connected to the transformer windings(W 1, W 1a..W 1n, W 2, W 2a..W 2n, W 3, W 3a..W 3n )can be switched in series or in parallel are provided.