The current sensor comprises: a magnetic detecting device that is arranged in the vicinity of a conductor, to which a magnetic field to be measured induced by a current flowing through the conductor is applied, and that changes an electrical resistance in response to a change in the magnetic field to be measured; two coils that generate a canceling magnetic field to cancel the magnetic field to be measured and that are arranged in the vicinity of the magnetic detecting device; a shunt resistor, that is connected in series between the two coils, for detecting a current flowing through the coils; a first differential amplifier that amplifies the output signal of the magnetic detecting device and that supplies the current to induce the canceling magnetic field to the coils; and a second differential amplifier that amplifies the voltage across the shunt resistor and that outputs a measured voltage proportional to the current flowing through the conductor.

A current detection device includes a plate-shaped bus bar that enables a current to be measured to pass therethrough, a magnetic sensor disposed at a position that faces the bus bar in the thickness direction of the bus bar, where the magnetic sensor measures a magnetic field generated when the current flows through the bus bar, and first and second shields made of a magnetic material. The first and second shields are disposed to sandwich the bus bar and the magnetic sensor in the thickness direction, and the first and second shields are disposed adjacent to the magnetic sensor and the bus bar, respectively. The first and second shields are configured such that the ratio of the magnetic flux density inside the first shield to the magnetic flux density inside the second shield is in the range of about 1:1 to 1:2 when the current is flowing through the bus bar.

A current sensor includes a plurality of unit groups mounted in a first case and a current sensor includes a first case that is made of a resin and includes a first opposing part, a second case that is made of a resin and includes a second opposing part, a substrate mounted in at least one of the first case and second case, and a plurality of unit groups mounted in the first case and second case, each unit group measuring an induced magnetic field. second case, each unit group measuring an induced magnetic field. Each of the plurality of unit groups includes one or more measurement units arranged in a second direction. A current path and a first magnetic shield, each of which is formed integrally with a first opposing part, are positioned so as to be separated by a first distance. In all unit groups, all first distances are substantially the same. The current path and a magneto-electric conversion element, which is formed integrally with a second opposing part, are positioned so as to be separated by a second distance. In all measurement units included in a unit group shared among them, all second distances are substantially the same. The second distance differs for each unit group. The thickness of the first opposing part in a first direction is substantially constant. The thickness of the second opposing part in the first direction is substantially constant.

A current sensor package, comprises a current path and a sensing device. The sensing device is spaced from the current path, and the sensing device is configured for sensing a magnetic field generated by a current flowing through the current path. Further, the sensing device comprises a sensor element. The sensing device is electrically connected to a conductive trace. An encapsulant extends continuously between the current path and the sensing device.

A current sensor includes three bus bars, each of which has recesses. The third bus bar is between the first and second bus bars. The recesses of the first and second bus bars are symmetrical about a virtual line that passes through the center of the third bus bar. The third bus bar has two recesses that are symmetrical about the same virtual line.

The current sensor for the current path includes: the current path; a magnetic detection unit having a magnetic detection element opposed to the current path and converting an alternating-current magnetic field generated from the current path into an electric signal, a signal line and a reference potential line; and a wiring board, on which the magnetic detection unit is mounted, having an insulation base and a wiring with a signal wiring connected to the signal line and a reference potential wiring connected to the reference potential line. A part of the signal wiring and a part of the reference potential wiring are arranged inside the insulation base.

A sensor includes a detector configured to sense a parameter, at least one test circuit configured to detect a respective fault condition of the sensor and generate a fault signal in response to detecting the fault condition, a checker configured to test the at least one test circuit to determine the operational status of the at least one test circuit, and an output signal generator, coupled to receive the sensed parameter, the fault signal, and the operational status of the at least one test circuit. The output signal generator is configured to generate an output signal of the sensor to communicate the sensed parameter and the operational status of the at least one test circuit.

A current sensor system for measuring an AC electrical current, comprising: a busbar having a thickness and a width; a sensor device comprising two sensor elements spaced apart along a first direction for measuring two magnetic field components oriented in a second direction; the sensor device configured for determining a magnetic field difference, and for determining the AC current based on said difference. The sensor device is positioned relative to the busbar such that a reference point in the middle between the two sensor elements is located at a first distance from a side of the busbar from 70% to 110% or from 70% to 95% of the width of the busbar and is located at a second distance from 0.5 to 4.0 mm from the busbar.

A magnetic field detection apparatus includes a magnetoresistive effect element and a conductor. The magnetoresistive effect element includes a magnetoresistive effect film extending in a first axis direction and including a first end part, a second end part, and an intermediate part between the first and second end parts. The conductor includes a first part and a second part that each extend in a second axis direction inclined with respect to the first axis direction. The conductor is configured to be supplied with a current and thereby configured to generate an induction magnetic field to be applied to the magnetoresistive effect film in a third axis direction orthogonal to the second axis direction. The first part and the second part respectively overlap the first end part and the second end part in a fourth axis direction orthogonal to both of the second axis direction and the third axis direction.

The current sensor has a conductive member through which a current to be measured flows in a predetermined direction, and a magneto electric converter facing and spaced apart from the conductive member in an intersecting direction intersecting the predetermined direction. An opposing portion of the conductive member facing the magneto electric converter has an annular shape in which two tip surfaces face each other via a gap around the predetermined direction. The magneto electric converter is opposed to the hollow portion, arranged in the opposing portion having an annular shape, in the intersecting direction via the gap.