An electromagnetic actuator (1) includes sensor magnets (21a, 21b) disposed correspondingly to plungers (11a, 11b), respectively. The electromagnetic actuator (1) further includes a sensor core (22) made of a magnetic material and disposed in a position through which magnetic fluxes from the plurality of sensor magnets (21a, 21b) can flow, and a magnetic sensor (23) that is disposed in a part of the sensor core (22) through which the magnetic fluxes of the plurality of sensor magnets (21a, 21b) can flow in common, and that detects the magnetic flux, which varies in accordance with respective positions of the plurality of plungers (11a, 11b).

An inductive position sensor is configured to determine a position of a target device. The inductive position sensor comprises at least two coils for determining said position. At least two of the at least two coils for determining the position at least partially overlap. The at least two coils each have a plurality of portions being equally distributed over N substantially parallel planes, with N being an integer larger than or equal to two. For each of the at least two coils the portions distributed over the N substantially parallel planes are substantially identical, so that mutual inductance between the at least two coils is substantially unaffected by misalignments between the N substantially parallel planes.

The present invention relates to an inductive position sensor configured to determine a position of a target device, comprising at least one receiving coil arranged to receive a magnetic field and an inner transmitting coil winding and an outer transmitting coil winding arranged to generate said magnetic field, whereby said at least one receiving coil is positioned between said inner transmitting coil winding and said outer transmitting coil winding and whereby said inner transmitting coil winding and said outer transmitting coil winding are so arranged that current flows in the same sense.

A speed detection device includes a comparator module, a sensor lead with a node connected to the comparator module, and a limit set module. The limit set module is connected to the sensor lead node and to the comparator by an upper limit lead and a lower limit lead to provide upper and lower limits to the comparator that vary according to amplitude variation in voltage applied to the sensor lead.

An angular rotation sensor system constituted of: an input shaft target and an output shaft target each comprising a plurality of members parallel to a longitudinal axis of an input shaft or output shaft; a gear target with an angular velocity exhibiting a predetermined ratio with an angular velocity of the input shaft, the gear target comprising a plurality of members, each extending away from the input shaft and orthogonal to a plane which is parallel to the longitudinal axis of the input shaft; and a control circuitry arranged to: determine an angular position of the input shaft responsive to a sensed angular rotation of the input shaft target and a sensed angular rotation of the gear target; and determine the amount of torque applied to the input shaft responsive to the sensed angular rotation of the input shaft target and a sensed angular rotation of the output shaft target.

Methods and apparatus for high speed location determinations are disclosed. An example apparatus includes at least two coils arranged along a zone of interest to generate a magnetic field, and a sensor to measure a change in the magnetic field associated with the at least two coils as an object of interest moves within or into the zone of interest. The example apparatus also includes a processor to determine a position of the object of interest based on the measured change.

Described examples include devices and methods for measuring relative humidity of an environment using inductance. The devices can include a resonant circuit, including a capacitor and an inductor. The inductor includes a moisture-absorbing core with at least a portion thereof exposed to an environment, with at least one magnetic property of the core being variable in response to changing levels of moisture in the environment. An excitation circuit provides an AC excitation signal to the resonant circuit. A sense circuit determines an inductance of the inductor according to a sense signal from the resonant circuit. The sense circuit is coupled to generate an output signal that indicates a humidity level of the environment according to the sense signal.

A device for inductive position determination comprises a coil, a positional element, a scanning device for determining an inductance of the coil and an evaluation device for determining a position of the positional element in relation to the coil, based on the inductance determined. In certain embodiments, the positional element comprises a ferromagnetic and electrically insulated material.

An apparatus for detecting a position of a rotor of a DC motor with N phases having a plurality of windings. The apparatus includes circuitry to couple at least two of the windings between a supply voltage and a reference voltage according to a first current path and allow the current stored in the two windings to be discharged through a second current path. The circuitry is configured to force the at least two windings at a short circuit condition in the second current path. The apparatus also includes a measurement circuit configured to measure the time period of discharging the current stored in the two windings and a rotor position detector for detecting the rotor position based on the measured time period.

An apparatus and method of detecting movement of a plunger of the solenoid includes detecting a peak (I.sub.PEAK) in a current signal applied to a coil of the solenoid. A predetermined threshold is added to the current signal applied to the coil of the solenoid to generate a level shifted signal. The level shifted signal and the peak signal are compared to detect movement of a plunger of the solenoid.