A system for interfacing an LC sensor includes a starter configured to selectively start an oscillation of the LC sensor. The system also includes an analog peak detector configured to determine a signal (V.sub.peak) being indicative of a peak voltage of the oscillation of the LC sensor and a detector configured to determine a state of the LC sensor as a function of the signal (V.sub.peak) determined by the analog peak detector.

A sensor apparatus for detecting a target object is provided, together with a corresponding method for operating the sensor apparatus. The sensor apparatus comprises a transmitter device which is operated by periodic excitation signals at a basic frequency, a receiver device which couples to the transmitter device, wherein the coupling is dependent on a relative position of the target object with respect to the receiver device, and the receiver device delivers signals at the basic frequency which are dependent on the relative position of the target object with respect to the receiver device. A threshold value checking device checks whether signals lie within or outside a threshold value range. A linking device acts on signals from the receiver device or signals derived therefrom in such a way that signals or signal combinations are shifted into the threshold value range insofar as they previously lay outside this range.

An apparatus for identifying when an individual is in proximity to an object having a sensor portion having an electromagnetic field. The apparatus has a personal alarm device that is worn by the individual which detects the presence of the magnetic field and produces a signal indicating the personal alarm device is within the electromagnetic field. The sensor portion having an exclusion zone where the electromagnetic field is effectively negated so the PAD does not produce an alarm in the exclusion zone. A method for identifying when an individual is in proximity to an object. A field extension module. A proximity device.

A magnetic field sensor includes at least one coil responsive to an AC coil drive signal; at least two spaced apart magnetic field sensing elements responsive to a sensing element drive signal and positioned proximate to the at least one coil; and a circuit coupled to the at least two magnetic field sensing elements to generate an output signal of the magnetic field sensor indicative of a difference between a distance of a conductive target with respect to each of the at least two spaced apart magnetic field sensing elements.

A proximity sensor includes a transmission circuit that supplies a current to each of detection coils, a reception circuit that detects voltages generated at both ends of the coils or currents flowing in the coils due to the supply of the current for each of the coils, a control unit that senses the presence or position of a detection object using a detection result of the reception circuit, and an output unit that outputs a sensing result of the control unit. The control unit extracts a first component caused by a mounting fitting for mounting the proximity sensor on a support member and a second component caused by the detection object from the detection result of the reception circuit. The control unit compensates the second component using the first component. The control unit senses the presence or position of the detection object on the basis of the compensated second component.

An inductive proximity switch comprising signal oscillating circuit and a reference oscillating circuit; multiplexer circuit designed to alternately activate the signal oscillating circuit and the reference oscillating circuit; driver circuit having an oscillator designed to operate the activated signal oscillating circuit and the activated reference oscillating circuit with an oscillator frequency, respectively; detection module designed to determine a number of oscillations of the activated signal oscillating circuit measured within a predetermined gate time and a number of oscillations of the activated reference oscillating circuit measured within the predetermined gate time; and an evaluation module designed to determine a difference signal on basis of the determined number of oscillations of the activated signal oscillating circuit measured within the predetermined gate time and the determined number of oscillations of the activated reference oscillating circuit measured within the predetermined gate time, and to generate a control signal depending on the difference signal.

A proximity sensor is provided with coils (11, 12) disposed in a pre-set positional relationship, a first distance calculation unit (31) and a second distance calculation unit (32) for calculating first distance information (d1) and second distance information (d2), respectively, from the coils (11, 12) to a detection object (W) on the basis of reception results (voltages V1, V2) of the coils (11, 12), and a position estimating unit (33) for estimating the position, such as distance and azimuth, of the detection object (W) on the basis of the first distance information (d1), the second distance information (d2), and the positional relationship of the coils (11, 12) .

An explosion-proof electronic system. The system comprises a substantially explosion-proof enclosure, a substantially explosion-proof glass window forming a portion of the enclosure, an electrical coil located within the enclosure, an electrical excitation circuit located within the enclosure and connected to the electrical coil, where the excitation circuit is configured to cause the electrical coil to establish a magnetic field that extends through the explosion-proof glass window, and a processor located within the enclosure and coupled to the electrical excitation circuit. The processor is configured to monitor the electrical excitation circuit, determine an electrical inductance of the electrical coil based on monitoring the electrical excitation circuit, identify a fluctuation of the electrical inductance that exceeds a predetermined threshold as a control input, and transmit an output in response to the control input, whereby a human operator can provide the control input by bringing a finger proximate to the explosion-proof glass window.

An axle counting method for rail-mounted vehicles is disclosed. An electromagnetic transmission signal with a frequency is produced, by a frequency source. The electromagnetic transmission signal is transmitted by means of a transmission device of an electromagnetic rail contact element. The electromagnetic transmission signal is detected as a first reception signal and a second reception signal by means of two spaced-apart receiving units of the rail contact element. The reception signals are transmitted. An evaluation signal is generated within a signal processing unit. To generate the transmission signal, a single transmission unit is used, and in that the reception signals received by the two receiving units originate from the same transmission signal.

The present disclosure aims to provide a high-durability switch device. The switch device includes: a switch key top and a switch key bottom that are freely displaceable relative to each other, the switch key top including key top reception and transmitting coils that are connected to each other, and the switch key bottom including: a key bottom transmitting coil having a relative positional relationship with the key top receiving coil that changes according to a relative displacement operation with respect to the switch key top; a key bottom receiving coil having a relative positional relationship with the key top transmitting coil that changes according to the relative displacement operation with respect to the switch key top; a current supplier supplying current to the key bottom transmitting coil; and a determiner determining relative displacement with respect to the switch key top from induced current in the key bottom receiving coil.