A wearable audio device with a magnetic field sensor that is constructed and arranged to sense the Earth's magnetic field. A magnet in the earphone, for example the magnet of the electro-acoustic transducer, produces a first magnetic field having a first magnetic field strength. A docking or parking magnet in the earphone produces a second magnetic field that is configured to reduce an influence of the first magnetic field on the magnetic field sensor.

A magnetic sensor includes a magnetic field converter, a magnetic field detector, and a plurality of shields aligned in a Y direction. The magnetic field converter includes a plurality of yokes. Each yoke has a shape elongated in the Y direction, and is configured to receive an input magnetic field component in a direction parallel to a Z direction and to output an output magnetic field component in a direction parallel to an X direction. The magnetic field detector includes a plurality of trains of elements. Each train of elements includes a plurality of MR elements that are aligned in the Y direction along one yoke and connected in series. Each shield has such a shape that its maximum dimension in the Y direction is smaller than its maximum dimension in the X direction.

A device with position detection includes: a first hall element; a second hall element; a differential amplifier configured to generate a subtraction voltage by differentially amplifying a first hall voltage generated by the first hall element and a second hall voltage generated by the second hall element; a summing amplifier configured to generate a sum voltage by summatively amplifying the first and second hall voltages; a comparer configured to compare a reference voltage with the subtraction voltage to generate an error voltage; and a current converter configured to generate a bias current provided to the first and second hall elements, based on the error voltage, wherein the device is configured to detect a position of a detection object based on the sum voltage.

The present disclosure generally relates to a tunnel magnetoresistive (TMR) device. The TMR device includes a high radiation reflective layer between the bottom shield of the TMR device and the magnetic seed layer. The high radiation reflective layer helps to maintain the TMR device temperature during transportation between processing chambers. Additionally, the high radiation reflective layer decreases the resistance area (RA) of the TMR device while also increasing the magnetoresistance (MR) of the TMR device.

A circuit for sensing the driving current of a motor, the circuit comprising: a driver configured to generate a driving current for each phase of a multiple-phase motor, the instantaneous sum of all the driving currents being zero; a current sensor for each phase of the multiple-phase motor, each current sensor configured to measure the driving current of that phase and comprising a plurality of current sensor elements arranged with respect to each other such that each current sensor element has the same magnitude of driving current systematic error due to magnetic fields external to the driving current to be measured; and a controller configured to, for each phase of the multiple-phase motor, generate an estimate of the driving current of that phase to be the measured driving current of that phase minus 1/n of the total of the measured driving currents for all phases, n being the number of phases of the multiple-phase motor.

A torque sensor includes: a torsion bar coaxially connecting a first shaft and a second shaft; a multipole magnet; a pair of magnetic yokes; and a magnetic sensor capable of detecting a density of magnetic flux formed by the pair of the magnetic yokes and having an inner magnetosensitive surface facing inward in a radial direction and an outer magnetosensitive surface facing outward in the radial direction when viewed along a central axis of the torsion bar. The torque sensor includes: a magnetic flux guiding member capable of magnetically coupling the magnetic yoke and the outer magnetosensitive surface of the magnetic sensor; and a water blocking portion capable of housing the magnetic sensor and the magnetic flux guiding member to restrict the magnetic sensor from coming into contact with water.

A tool, system, and method are disclosed for locating a hidden stud and identifying angles on a finished wall. The tool includes an elongated housing, at least one magnet, and at least one level. The housing has a generally planar contact surface disposed opposite a viewing surface. The at least one magnet is secured to the housing such that a magnetic field from the at least one magnet extends from the contact surface. The level is secured to the housing such that the level is viewable from the viewing surface. The at least one magnet, the level, and the housing are sized relative to each other such that a magnetic attraction between the at least one magnet and a metallic element in the wall is sufficient to maintain the tool on the wall without external support.

A current sensor for detecting a magnitude of a current flowing through a measuring object has a magnetic core having a first magnetic core and a second magnetic core that is arranged magnetically in parallel to the first magnetic core, wherein the first magnetic core has a magnetic permeability that is higher than that of the second magnetic core in a first frequency band, and the first magnetic core has a magnetic permeability that is lower than that of the second magnetic core in a second frequency band, the second frequency band being higher than the first frequency band, and the current sensor detects the magnitude of the current in a frequency band that is constituted by combining the first frequency band and the second frequency band.

A magnetic sensor capable of reducing noise caused by an interference magnetic field and capable of outputting a highly accurate signal in accordance with changes in a detected magnetic field includes a magnetic detection element, a first magnetic body having a first surface and a second surface, which is opposite to the first surface, and a second magnetic body positioned approximately in the center of the first magnetic body in the short direction on the first surface of the first magnetic body. The magnetic detection element is provided to be opposite to the second magnetic body with the first magnetic body interposed in between and positioned approximately in the center of the first magnetic body in the short direction. The magnetic sensing direction of the magnetic detection element is a direction approximately parallel to the short direction of the first magnetic body and the second magnetic body, and a width W1 of the first magnetic body is larger than a width W2 of the second magnetic body.

A magnetic substance detection sensor includes a support substrate, a semiconductor chip provided on the support substrate and having a magnetic field detection element, a permanent magnet provided on the support substrate, and a resin encapsulation layer covering the semiconductor chip and the permanent magnet. The resin encapsulation layer has a first resin layer exposing the permanent magnet and covering the semiconductor chip, and a second resin layer continuously covering the permanent magnet and the first resin layer, and stress caused by curing contraction of the second resin layer is smaller than that of the first resin layer.