A sensor system for detecting a characteristic of a target object is described. The sensor system can include a sensor, such as a magnetic sensor, configured to sense magnet field components and to generate corresponding magnet field component signals based on the sensed magnet field components. The sensor system can include a processor that is configured to calculate a magnetic field angle based third magnetic field components. For example, the magnetic field angle can be calculated by determining a quadratic sum of a plurality of the magnetic field components. The characteristic of the target object can be determined based on the calculated magnetic field angle.

A rotating device sensing apparatus includes: a rotating device comprising a detection target unit; a pattern portion formed in the detection target unit in a direction of rotation of the rotating device; a first sensor disposed to face one region of the detection target unit; and a second sensor, spaced apart from the first sensor, and disposed to face another region of the detection target unit, wherein the pattern portion comprises a first pattern portion and a second pattern portion having different widths.

A magnetic angular position sensor system is described herein. According to one exemplary embodiment the angular position sensor system comprises a shaft rotatable around a rotation axis, wherein the shaft has a soft magnetic shaft end portion. The system further comprises a sensor chip spaced apart from the shaft end portion in an axial direction and defining a sensor plane, which is substantially perpendicular to the rotation axis. At least four magnetic field sensor elements are integrated in the sensor chip, wherein two of the magnetic field sensor elements are spaced apart from each other and are only sensitive to magnetic field components in a first direction and wherein two of the magnetic field sensor elements are spaced apart from each other and are only sensitive to magnetic field components in a second direction, whereby the first and the second direction are mutually non-parallel and the first and the second direction being perpendicular to the rotation axis. Moreover, the system comprises a magnetic field source that magnetizes the shaft end portion, wherein the shaft end portion is formed such that a magnetic field in the sensor plane, which is caused by the magnetic field source, is rotationally symmetric with order N, wherein N is a finite integer number ≧1. The system also comprises circuitry that is coupled to the at least four magnetic field sensor elements and configured to calculate an angular position of the shaft by combining output signals of the at least four magnetic field sensor elements.

A power tool including a motor and an impact mechanism. The impact mechanism is coupled to the motor and includes a hammer driven by the motor, and an anvil positioned at a nose of the power tool, and configured to receive an impact from the hammer. The power tool also includes a sensor assembly positioned at the nose of the power tool, and an electronic processor. The sensor assembly includes an output position sensor configured to generate an output signal indicative of a position of the hammer or the anvil. The electronic processor is coupled to the output position sensor and to the motor, and is configured to operate the motor based on the output signal from the output position sensor.

A sensor for sensing an angular position of a rotatable element with respect to a non-rotatable element, the sensor comprising an encoder fast in rotation with the rotatable element, and a sensor body fixed respective to the non-rotatable element. The sensor body includes at least one sensing element adapted to sense angular position or rotation speed and direction of the encoder, a signal processor support member, and a sensing data output connector comprising at least one electrical wire connected to the support member. The sensor comprises a tubular body (accommodating the connector), including a first half-shell integral with the sensor body and a second half-shell assembled with the first half-shell around the connector. A tubular body internal surface comprises at least one radial ridge adapted to block a translation of the output connector along a longitudinal axis of the tubular body by penetrating into a sheath of the connector.

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.

A magnet for detection mounted on a rotating shaft rotating about a rotation axis, and a detector disposed opposite to the magnet for detection to detect rotation of the rotating shaft are included. The detector includes a multi-layer circuit board, a recessed groove that is provided in an interlayer of the circuit board, has a center on an extension of the rotation axis, and is orthogonal to the rotation axis, a combined magnetic wire incorporated in the recessed groove and exhibiting a large Barkhausen effect, and a pickup coil formed of wiring conductors on the circuit board and a conductor with which through holes are filled, to surround the combined magnetic wire.

This disclosure provides systems, methods and apparatus for detecting foreign objects. In one aspect an apparatus for detecting a presence of an object is provided. The apparatus includes a resonant circuit having a resonant frequency. The resonant circuit includes a sense circuit including an electrically conductive structure. The apparatus further includes a coupling circuit coupled to the sense circuit. The apparatus further includes a detection circuit coupled to the sense circuit via the coupling circuit. The detection circuit is configured to detect the presence of the object in response to detecting a difference between a measured characteristic that depends on a frequency at which the resonant circuit is resonating and a corresponding characteristic that depends on the resonant frequency of the resonant circuit. The coupling circuit is configured to reduce a variation of the resonant frequency by the detection circuit in the absence of the object.

Circuits for controlling magnetic-based tracking systems are described. These systems may be used in virtual reality applications, for example to track in real-time the location of one or more body parts. The systems use a beacon emitting mutually orthogonal magnetic fields. On the receiver side, one or more sensors disposed on different parts of a body receive the magnetic fields. The beacon includes switching amplifiers for driving the magnetic field emitters. Being binary, these amplifiers may be controlled by binary signals. The circuits may exhibit a resonant frequency response, and may be operated off-resonance, thus providing for a better control of the magnetic fields amplitude. As a result, however, fluctuations in the envelop of the magnetic fields due to the presence of a beating tone may arise. These fluctuations may be shortened by gradually activating the drivers for the magnetic field emitters.

An electronic absolute position encoder includes a scale extending along a measuring axis direction (MA) and including a signal modulating scale pattern defining a corresponding absolute range R along MA, a detector including sensing elements arranged along MA and configured to provide detector signals which respond to the signal modulating scale pattern, and a signal processing configuration that determines an absolute position of the detector along the scale based on the detector signals. The signal modulating scale pattern includes a coarse periodic pattern component as a function of position along the scale having a spatial wavelength λ.sub.C, wherein n*λ.sub.C=R and n is an integer, and a fine periodic pattern component as a function of position along the scale having a spatial wavelength λ.sub.F, wherein (mn+1)*λ.sub.F=R and m is an integer that is at least two. The wavelengths λ.sub.C and λ.sub.C may be widely separated.