Magnetic bearing apparatus

A magnetic bearing apparatus having a stator which includes a winding for the generation of a magnetic control field, having a rotor which can be magnetically journalled with respect to the stator, and also having a sensor device configured as an eddy current sensor for the determination of the spacing between the stator and the rotor, wherein the sensor device includes at least one sensor element configured as an inductor and at least one capacitor which forms an electrical resonant circuit with the inductor, as well as having a control unit for the control of the sensor device and for the evaluation of the detected signals, characterized in that the inductor is arranged electrically in series to the capacitor so that the electrical resonant circuit is a serial resonant circuit, wherein each sensor element is configured as air core coil, wherein the amplitude of the measured signal originating from the respective resonant circuit is larger than the amplitude of the excitation signal used for exciting the respective resonant circuit by at least a factor of 2.