A device has a construction capable of promoting miniaturization, and comprises: a coil; a magnetism-responsive member disposed so as to be displaced relative to the coil according to a position of a detection object; and a self-oscillation circuit that incorporates the coil therein as an oscillation element so that an oscillation frequency varies with an inductance variation of the coil responsive to an displacement of the magnetism-responsive member relative to the coil. An arithmetic section generates a measured value responsive to oscillation frequency based on an oscillation output of the self-oscillation circuit, calculates velocity data by differentiating successive measured values, and calculates displacement data by integrating the velocity data. An offset error component caused by the peripheral temperature or a mechanical attachment position of the detection device can be automatically cancelled or reduced by the differential operation for calculating the velocity data, and precise displacement detection can be realized.

A vehicle driveline component including an armature disposed along a translation axis; a coil assembly having a coil; a coil driver electrically coupled to the coil; the coil driver generates an electromagnetic field that causes relative motion between the coil assembly and the armature along the translation axis; an oscillator circuit having a resonant circuit including an inductor, the oscillator circuit electrically coupled to the coil generating an oscillating signal having a frequency that varies based on a spacing between the armature and the coil assembly along the translation axis; and a controller coupled to the oscillator circuit and the coil driver, wherein the controller is configured to apply a drive signal to the coil driver to provide the modulating power signal to the coil assembly, measure a frequency value of the oscillator circuit, and determine a position of the vehicle driveline component based on the measured frequency value.

In one embodiment, a sensor arrangement for the contactless sensing of angles of rotation on a rotating part includes a disk-shaped target coupled to the rotating part. The disc-shaped target has at least one metal surface and generates at least one piece of information for ascertaining the instantaneous angle of rotation of the rotating part in connection with a coil arrangement. The coil arrangement has at least one flat detection coil. The arrangement further includes at least one measuring circuit that converts the inductance of a corresponding at least one flat detection coil into a measuring signal. The inductance changes due to eddy-current effects, as a function of the degree of overlap with the at least one metal surface of the rotating target. The arrangement further includes an evaluation and control unit that detects the measuring signal using measurement techniques and evaluates the signal for calculating the angle of rotation.

A sensor including a set of coils. The set of coils include a first coil and a second coil, wherein the first coil upon receiving energy, generates an electromagnetic near-field, such that the electromagnetic near-field provides at least a portion of the energy to the second coil through inductive coupling, inducing a current to pass through the set of coils. Further, a detector for measuring a voltage across at least one of the first coil or the second coil, wherein the detector includes a voltmeter. Finally, a processor for detecting a presence of a target structure in proximity to the set of coils upon detecting a change in a value of the voltage, wherein the target structure is an electromagnetic structure moving at a distance from the set of coils.

The present invention relates to a system (100, 300, 400) for detecting abnormal movement of a gas turbine shaft. The system comprises: a magnetic circuit (104, 302, 402) comprising a first magnetic portion (110, 304) and a second portion (112, 404), and including at least one air gap between the first portion and the second portion; and a detection coil (106) wound around the first magnetic portion. The second portion is coupled to or moveable with the shaft to reduce the air gap, on axial movement of the shaft to change the reluctance of the magnetic circuit and thereby induce a voltage in the coil. The system may comprise a controller (108) for shutting off power to the gas turbine when the induced voltage exceeds a threshold voltage.

Front-end circuits that combine inductive and capacitive sensing are described. In one embodiment, an apparatus includes a plurality of inductive elements, an inductive measurement circuit, and a frequency divider circuit. The inductive measurement circuit is to output a first signal with a first frequency. The first signal is associated with an inductance change of one of the inductive elements. A feedback circuit can maintain the sinusoidal operation of the first signal. The frequency divider circuit can generate a second signal with a second frequency that is lower than the first frequency.

The disclosure relates to a linear actuator, the housing of which encloses a pushrod which is guided displaceably along a longitudinal axis. The linear actuator includes a linear travel sensor intended for determining a position of the pushrod. A housing-side position receiver of the linear travel sensor includes a receiver section extending along the longitudinal axis, and a pushrod-side position transmitter that interacts contactlessly with the position receiver. The position transmitter is made from an electrically conductive material, and a transmitter contour of the linear travel sensor is curved about at least one dimensional axis.