Electrical supply system

Disclosed is an electrical isolator for isolating a power supply (400). The isolator includes a voltage converter (410) having a voltage converter input (410.1) electrically coupled to a supply (S4) for receiving a supply signal and a voltage converter output (410.2) for supplying an output signal. The output signal has an output voltage different to a supply voltage of the supply signal. The convertor (410) further includes a transformer (TR), a switching circuit coupled to the voltage converter input (410.1) and the transformer (TR); and a controller (470) that controls the switching circuit. The converter (410) is controlled to generate the output signal and electrically isolate the voltage converter input (410.1) from the voltage converter output (410.2).