Abstract: A charging device for charging an energy storage device of a portable electric device. The charging device has a load cell or load cells, each load cell is equipped with a controllable resonant circuit for inductively transmitting energy, a parallel resonant circuit with two coils and a controllable supply voltage, two controllable switching elements for a self-oscillation of the parallel resonant circuit, which have control connections that can be connected to each other via a respective controllable switch-off element, and a demodulator connected to an output of the load cell being formed by a coil end of one coil of said two coils, wherein said coil end is not connected to a coil end of another coil of said two coils. The self-oscillation can be interrupted in a controlled manner by switching the two controllable switching elements in order to modulate an amplitude of an electromagnetic field generated by the two coils.

Abstract: A charging device for charging the energy storage device of a portable electric device. The charging device has a load cell or load cells with a controllable resonant circuit for inductively transmitting energy, a parallel resonant circuit with two coils and a controllable supply voltage, two controllable switching elements for a self-oscillation of the parallel resonant circuit, which have control connections that can be connected to one another via a respective controllable switch-off element, and a demodulator connected to an output of the load cell being formed by a coil end that is not connected to the other coil end. The self-oscillation can be interrupted in a controlled manner by switching the controllable switching elements in order to modulate the amplitude of the electromagnetic field generated by the coils.

Abstract: A winding band including at least one conductor is arranged on a carrier in a housing, and is coupled to a rotative part, so that a wound-up length of a wound-up portion of the winding band varies corresponding to a rotational movement of the rotative part. At least one measuring inductor is arranged proximate to the wound-up portion of the winding band. The angular position of the rotative part is determined by detecting an electromagnetic field coupling between the measuring inductor and the wound-up portion of the winding band, and evaluating the amplitude, frequency and/or phase of an induced voltage arising in the inductor due to the coupling.