In one embodiment, an inductive/LC sensor device includes: an energy storage device for accumulating excitation energy, an LC sensor configured to oscillate using energy accumulated in the energy storage device and transferred to the LC sensor, an energy detector for detecting the energy accumulated in the energy storage device reaching a charge threshold, and at least one switch coupled with the energy detector for terminating accumulating excitation energy in the energy storage device when the charge threshold is detected having been reached by the energy detector.

The present disclosure provides a proximity switch. The proximity switch includes an oscillating circuit. The oscillating circuit is configured to detect an object to be sensed. The oscillating circuit has a resonant frequency, and the resonant frequency is in a range of from 0.8 MHz to 20 MHz. The present disclosure further provides a method for detecting an object to be sensed.

The invention generally relates to a field regulator, particularly a field regulator for a resonant circuit, a transmitter including such a field regulator, a proximity detection system including such a transmitter, and a method of regulating a resonant circuit. In one aspect the invention provides a field regulator for a resonant circuit, the resonant circuit including an inductor coil around a core, the field regulator including a DC bias circuit configured to apply a DC bias current to the inductor coil for regulating an electromagnetic field generated by the inductor. The DC bias circuit can be used to selectively change the inductance of the inductor in the resonant circuit so as to maintain a consistent field strength in a changing environment, particularly to take into account the presence of large metal bodies which might otherwise adversely impact on operation. In particular, the DC bias current may be used to selectively change the natural frequency of the resonant circuit so as to shift the resonant circuit towards a desired resonance point.

A method may include receiving an input signal, generating a baseline signal based on the input signal, generating a corrected input signal by subtracting the baseline signal from the input signal, determining a threshold level change of the input signal when the corrected input signal exceeds a level change threshold, and responsive to the threshold level change, updating the baseline signal to the level change threshold.

An electronic module for an inductive sensor apparatus is provided which comprises at least one voltage-controlled current source, a current source port connected to the at least one voltage-controlled current source for providing a voltage-controlled current from the at least one voltage-controlled current source, an adder device, an adder input port connected to the adder device, and an adder output port which is connected to the adder device. The current source port is connectable to an electrical resonant circuit and/or to a coil element. The adder input port is connectable to the current source port or to at least one further coil element. By way of the adder device, an operation of addition and/or subtraction of a voltage applied to the adder input port and at least one offset voltage is performed. An evaluation signal for evaluation by an evaluation device is providable at the adder output port.