A target value of magnetic flux density and magnetic flux density actually obtained are made to coincide precisely with each other. An electromagnet control device comprises a current value determining unit for determining, based on a magnetic flux density instruction value, a value of current that is made to flow through a coil. The current value determining unit is constructed to execute a second process for determining, based on a second function, a value of the current, if the magnetic flux density is to be decreased from that in a first magnetization state, and a fourth process for expanding or reducing the second function by use of a first scaling ratio for transforming it to a fourth function, and determining, based on the fourth function obtained after above transformation, a value of the current, if the magnetic flux density is to be decreased from that in a third magnetization state.

A sensor die may include a set of sensing elements and a test structure associated with determining a magnetic sensitivity of the set of sensing elements. The test structure includes a first test sensing element sensitive in a direction in a plane defined by a surface of the sensor die, a second test sensing element sensitive in the direction in the plane defined by the surface of the sensor die, and a wire on chip (WoC) associated with applying a magnetic field to the first test sensing element and the second test sensing element. The first test sensing element, the second test sensing element, and the WoC may be arranged such that, when current flows through the WoC, the first test sensing element senses a component of the magnetic field in the direction, and the second test sensing element senses a component of the magnetic field in a perpendicular direction.

A magneto-resistive angle sensor system for measuring a rotational angle of a rotating component in an out-of-shaft configuration. The magneto-resistive angle sensor system including a magnet, which is attached to the rotating component. The magneto-resistive angle sensor system further including a magneto resistive sensor. A sensitive plane of the magneto-resistive sensor is positioned with an offset to the center of the magnet in an offset direction.

Improved techniques for remotely monitoring and managing fasteners and fastener driver conditions, are provided. In some aspects of the invention, conditions of a fastener and/or structural material(s) held by the fastener and/or connector, are monitored by a control system including sensor(s) at least partially embedded in, on or throughout the fastener and/or structural material(s). When an adverse condition is sensed, a torque may be remotely applied to the fastener, in some embodiments. In some embodiments, other remedial actions may be taken by the control system. In some embodiments, such sensor(s) include a magnetizable array, which may include one or more charge-carrying and/or otherwise magnetic wires or particles on, about, or embedded within, the fastener and/or structural material. In some embodiments, such remote monitoring includes testing a magnetic signature of the fastener and/or structural material (e.g., via remote scanning and/or testing).

This proximity sensor includes: a cylindrical housing having an opening at one end in the axial direction; a detection part housed at the other end of the housing and detecting the presence or absence of a detection target contactlessly; a substrate housed in the housing and mounted with a control circuit for controlling the detection part; a detection part shield preventing external noise from entering the detection part and including a first face part adhered to the front surface on the other side of the detection part, and a side face part configured from multiple side pieces connected to the outer periphery of the first face part and bent from the first face part to cover the side surface of the detection part; and a resin provided around the detection part and the detection part shield.

This sensor includes: a housing 10 which houses an electronic component in the internal space; a detection unit 40 which has a coil 42 and a core 41 that houses the coil 42 and which is arranged on the end side in the internal space; a substrate 30 which is arranged more inside the internal space than the detection unit 40 and on which a circuit electrically connected to the coil 42 is provided; a first shield 451 at least one portion of which is arranged further on the end side in the internal space than the detection unit 40 and which suppresses the penetration of noise from outside of the housing 10; and a spacer 51 which is positioned between the first shield 451 and the detection unit 40 and which separates the surfaces of the first shield 451 and the detection unit 40 that face each other.

A frac dart including a pressure housing, a mechanically actuated magnetic sensor including a first magnet outside of the pressure housing, a signal generator inside the pressure housing and in operable communication with the first magnet, and an electrical counter disposed in the frac dart responsive in increments to the signal generator.

Axial magnetic flux sensors are described. The axial magnetic flux sensors comprise multiple substrates with conductive traces on them in some embodiments, and in other embodiments a single substrate or no substrate. When multiple substrates are provided, the substrates couple together such that the conductive traces connect to form a coil. The coil may be a continuous, multi-loop coil. When the substrates are coupled together, they may define an opening to accommodate a shaft or other piece of equipment.

A current measurement device (1 and 2) is for measuring a current (I) flowing through measurement target conductors (MC1 and MC2), and the current measurement device includes: a plurality of triaxial magnetic sensors (11, 12, and 13) disposed so that a magnetic sensing direction and a relative position have a prescribed relationship; a noise remover (25a) configured to remove noise components included in detection results of the plurality of triaxial magnetic sensors; a sign adder (25b) configured to add a sign to the detection results from which the noise components have been removed, based on sign information of each of the detection results of the plurality of triaxial magnetic sensors obtained at a specific point in time; and a current calculator (25c and 25d) configured to calculate a current flowing through the measurement target conductors by using the detection results to which the sign has been added by the sign adder.

A target value of magnetic flux density and magnetic flux density actually obtained are made to coincide precisely with each other. An electromagnet control device comprises a current value determining unit for determining, based on a magnetic flux density instruction value, a value of current that is made to flow through a coil. The current value determining unit is constructed to execute a second process for determining, based on a second function, a value of the current, if the magnetic flux density is to be decreased from that in a first magnetization state, and a fourth process for expanding or reducing the second function by use of a first scaling ratio for transforming it to a fourth function, and determining, based on the fourth function obtained after above transformation, a value of the current, if the magnetic flux density is to be decreased from that in a third magnetization state.