Electrical vehicle circuitry

A transformer circuit for an electric vehicle (EV, HEV) that can receive different input voltages and provide one or more output voltages. For example, the circuit may be capable of: accepting 800V or 400V at the same input; and/or supporting 800V and 400V traction systems, or supporting low voltage (e.g. 30-50V) and high voltage (400V or 800V) systems simultaneously. The circuit has a transformer with a primary winding 152 connected to an input 104 of the circuit and a secondary winding 102 connected to an output 106 of the circuit. Either, or both, of the primary and secondary windings includes first and second split windings. The circuit also includes at least one switching arrangement 166, 116. Where the primary winding has first and second split windings 162, 164, a primary switching arrangement 166 selectively: connects the first split winding to the input; or connects the first and second split windings in series to the input. Where the secondary winding has first and second split windings 112, 114, a secondary switching arrangement 116 selectively: connects the first split winding to the output; or connects the first and second split windings in series to the output.