The present invention provides an apparatus for sensing rotor location, the apparatus comprising: a central shaft; a magnet coupled to the central shaft; a sensor portion is disposed correspond to the magnet; wherein the sensor portion comprising a substrate, a first group including a first Hall sensor and a third Hall sensor disposed on the substrate, and a second group including a second Hall sensor and a fourth Hall sensor, the first Hall sensor and the third Hall sensor are arranged to overlap in a radial direction about the central shaft and the second Hall sensor and the fourth Hall sensor are arranged to overlap in a radial direction about the central shaft.

A linear magnetic encoder or position sensor having read head with a freely rotatable generally cylindrical bipolar magnet onboard having an axially extending axis of rotation through the center of the sensor magnet that is generally parallel with respect to the longitudinal extent of a plurality of pairs of elongate bar position magnets arranged with alternating opposite magnetic poles facing toward to the read head and sensor magnet that are generally aligned and spaced apart a common fixed distance along a track along which the read head and sensor magnet travels. Magnetic fields extending between the opposite magnetic poles of each pair of position magnets interact with and preferably magnetically couple with a magnetic field of the sensor magnet inducing a force, preferably a torque, therein driving the sensor magnet into rotation as the head and sensor magnet travel along the position magnet pair. One axial end of the sensor magnet is disposed adjacent and faces toward a sensor region of an onboard magnetic sensor configured to detect an angle of rotation and number of rotations of the sensor magnet used to determine a linear position along the track.

The invention discloses a multi-sensor position measurement system mainly comprising a base, a carrier and a modular component, the carrier is provided with a first signal array and a second signal array. The modular component is disposed on the base, and comprises two Hall sensors for sensing magnetic field changes of the first signal array, two magnetoresistive sensors for sensing magnetic field changes of the second signal array, and a first state sensor having a marking unit disposed on the carrier and a sensitive element disposed on the base for sensing signals generated by the marking unit for subsequent reference signal generation, connection of measurement results between other sensors, and identification of homing direction.

A control device includes a moving portion, a magnetic element coupled to the moving portion, at least one magnetic sensing circuit responsive to magnetic fields, and at least one magnetic flux pipe structure. The magnetic element may comprise alternating positive and negative sections configured to generate a magnetic field. The magnetic element may be any shape, such as circular, linear, etc. The magnetic sensing circuit may be radially offset from the magnetic element, and the magnetic flux pipe structure may be configured to conduct the magnetic field generated by the magnetic element towards the magnetic sensing circuit. The magnetic element may generate the magnetic field in a first plane, and the magnetic sensing may be responsive to magnetic fields in a second direction that is angularly offset from the first plane. The magnetic flux pipe structure may redirect the magnetic field towards the magnetic sensing circuit in the second direction.

An electric motor including a rotor defining an axis of rotation and an encoder. The encoder includes a magnetic composite part attached to the rotor, and a magnetic flux sensor positioned to detect magnetic flux resulting from movement of the magnetic composite part with rotation of the rotor.

The invention relates to a system comprising a coder that has an alternation of North and South magnetic poles separated by transitions extending along a helix of pitch p and of angle α, the magnetic track having N.sub.pp pairs of North and South poles and a polar width L.sub.p measured along a normal to the transitions which are: N.sub.pp=πa/l and L.sub.p=p.Math.cos α. The invention also includes at least one sensor able to detect the rotating magnetic field in a plane perpendicular to the magnetic track and to the transitions by means of a mounting of at least two sensitive magnetic elements. The mounting being disposed at a radial reading distance from the magnetic track and being arranged to deliver signals in quadrature.

A rotation operation device using magnetic force, which is compact and enables a user to perform a proper operation. The rotation operation device includes a rotation operation member rotatable about a predetermined axis. A ring-shaped magnet is magnetized in a magnetization direction parallel to the predetermined axis such that magnetic poles alternate. The magnet rotates about the predetermined axis along with rotation of the rotation operation member. A first magnetic body have first tooth portions formed at predetermined intervals along a circumferential direction and extending in radial directions of the magnet. The magnet overlaps with the first tooth portions in a direction of the predetermined axis. An operating physical force is generated according to changes in positions of the magnetic poles and the first tooth portions, which are caused by rotation of the magnet.

A blade angle feedback system for an aircraft-bladed rotor rotatable about a longitudinal axis and having an adjustable blade pitch angle is provided. A feedback device is coupled to rotate with the rotor and to move along the axis with adjustment of the blade angle. At least one position marker is affixed to a core of the feedback device and extends along a direction angled relative to the axis. The core is made of a first material having a first magnetic permeability and the position marker comprises a second material having a second magnetic permeability greater than the first magnetic permeability. A sensor is positioned adjacent the feedback device and produces, as the feedback device rotates about the axis, a sensor signal in response to detecting passage of the position marker. A control unit generates a feedback signal indicative of the blade angle in response to the sensor signal.

The magnetic detection device includes: a first magnetic rotary body which rotates about a rotation shaft and has an outer circumferential portion which is a magnetic body; a second magnetic rotary body has an outer circumferential portion which is a magnetic body; a magnet which has a magnetization direction along the axial direction; a first magneto-resistive element provided on another side in the axial direction of the magnet; a second magneto-resistive element provided on one side in the axial direction of the magnet; a first magnetic guide provided between the magnet and the first magneto-resistive element; and a second magnetic guide provided between the magnet and the second magneto-resistive element, wherein the outer circumferential portion of the first magnetic rotary body and the outer circumferential portion of the second magnetic rotary body cause different magnetic fields between the magnet and the respective outer circumferential portions.

In one aspect, an integrated circuit (IC) includes a magnetic-field sensor. The magnetic-field sensor includes digital circuitry that includes a first and second analog-to-digital converter (ADC). The digital circuitry is configured to receive a first and second analog output signals and, using the first and second ADC, configured to convert the first and second analog output signals to a first and second digital signals. The magnetic-field sensor also includes diagnostic circuitry configured to receive, from the digital circuitry, an input signal related to the first and/or the second digital signals and configured to provide a test signal at a pin of the IC. In response to a range parameter, the diagnostic circuitry is further configured to provide the test signal comprising a range of codes from the first and/or the second ADC corresponding to the range parameter.