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 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 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 determined by the analog peak detector.

Disclosed is a factor 1 and inductive sensor device including an LC resonant circuit powered by a suitable generator, an operational chain of units for acquisition by sampling and processing of the response signal, and a functional set of units for evaluating at least one temporarily set value of the processed signal and supplying detection or non-detection information. The acquisition and processing unit includes analog a unit for filtering and/or amplifying the sampled response signal, and a unit for compensating the temperature drift of the response signal by correcting the sampled signal following the digital conversion thereof, associated with or including a temperature sensor.

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.

To provide an elevator car position detection sensor capable of suppressing erroneous detection of presence or absence of a plate. The elevator car position detection sensor includes a first coil provided to one of an elevator car and a hoistway and configured to output an excitation magnetic field to a plate provided to the other of the elevator car and the hoistway; a second coil provided on an opposite side of the first coil relative to the plate; a shield wall configured to shield an end portion of the plate located closer to one of the car and the hoistway; and a determination circuit configured to determine a phase of an alternating-current voltage corresponding to a frequency of the excitation magnetic field output from the first coil at an alternating-current voltage generated across the second coil.

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.

A binary proximity switch comprises a frequency generator for providing an AC voltage; a coil connected to the AC voltage for generating an alternating magnetic field; an influencing element that is attached such that it can move in relation to the coil and is configured to influence the alternating magnetic field to different extents depending on its distance to the coil; a rectifier for rectifying the AC voltage applied to the coil; a comparator for determining whether or not the rectified voltage exceeds a predetermined threshold value; and an interface for providing a binary signal indicating the determination result.

An apparatus for identifying when an individual is in proximity to an object having a length has a sensor portion having a wire loop through which electric current runs and creates an electromagnetic field that emanates about the wire loop. The wire loop extending along at least a third of the length of the object. The apparatus has a personal alarm device that is worn by the individual which detects the presence of the magnetic field emanating from the wire loop when the personal alarm device is in the magnetic field and produces a signal indicating the personal alarm device is within the magnetic field. Alternatively, the sensor portion extends from a contiguous boundary up to 500 meters, where the boundary has a geometry that is linear or meandering. A head piece for an individual's head. A method for identifying when an individual is in proximity to an object. A field extension module. A proximity device.

The invention relates to an inductive proximity switch having a primary coil for generating an alternating magnetic field, with an oscillator for driving the primary coil, with a control and evaluation unit, which is operatively connected to the oscillator and is equipped to acquire and evaluate an amplitude and a phase position of a current in the primary coil and for outputting a detection signal depending on the acquired current in the primary coil, with at least one compensation coil for manipulation of the alternating magnetic field generated by the primary coil. The inductive proximity switch is characterized in that a separate controllable current source is present for controlling the at least one compensation coil.

A proximity sensor or switch having a sensing coil, an oscillator connected to the coil, a comparator connected to the oscillator, a reference voltage module connected to the comparator, and an output driver connected to the comparator. The voltage module may incorporate a resistor having an end connected to a high side of a power source, and a digital potentiometer having a first end connected to another end of the resistor and to the comparator, and having a second end connected to a ground side of the power source. The digital potentiometer may have a resistance that is varied with a signal. A variation of the resistance for the digital potentiometer may result in a change of a voltage from the reference voltage module which further changes a switching distance of the proximity switch to a predetermined value.