A power converter having a primary side and a secondary side galvanically isolated therefrom, includes a secondary-side functional unit operable in dependence on auxiliary information generated on the primary side, a primary-side voltage supply device arranged to provide a supply voltage, a power transmission device, which has a switching unit for switching the supply voltage and a transmission unit, which is set up to transmit the switched supply voltage to the secondary side, to convert the supply voltage into an operating voltage for the functional unit, a primary-side modulation device to provide a clock signal to the switching unit and to vary a frequency of the clock signal by the auxiliary information, and a secondary-side demodulation device arranged to generate at least one use signal representing the auxiliary information from a secondary voltage provided by the transmitter unit and to provide a use signal to the functional unit.