Alps Green Devices Co., Ltd.

Alps Electric Co., Ltd.

Tdk Corporation

Alps Alpine Co., Ltd.

Alps Green Devices., Ltd.

Akira Takahashi

Masamichi Saito

Yosuke Ide

Yoshihiro Nishiyama

Kenji Ichinohe

Masahiro Iizuka

Hidekazu Kobayashi

Naoki Sakatsume

Tsuyoshi Nojima

Eiji Umetsu

Takashi Hatanai

Shigenobu Miyajima

Tatsuya Kogure

Toshinori Watanabe

Mitsuo Aratono

Nobuhiro Hayashi

Kiyoshi Sato

Tomohiro Yamashita

Akihiro Makino

Jun Takahashi

Fumihito Koike

Yoshihiro Kanada

Hideaki Kawasaki

Naoki Sakazume

Naoya Hasegawa

Kiyoshi Kobayashi

Hiroyuki Hebiguchi

Kenji Honda

Ryo Nakabayashi

Isao Sato

Naohiro Ishibashi

Shinji Mitsuya

Shuji Yanagi

Yoshiaki Shimizu

Kunio Yamanaka

Yuko Kawasaki

Atsushi Sato

Mitsuhiro Goto

Takashi Fujisaki

Masato Nakamura

Hidenori Hataya

Hideharu Matsuo

A magnetic balance type current sensor includes a plurality of coils and a magnetic detection element whose characteristics change depending on a magnetic field induced by a current to be measured. Each of the plurality of coils includes a coil wire section disposed on a surface located away from a reference plane, a lead wire section connected to the coil wire section, and two electrode sections connected individually to the coil wire section and to the lead wire section. Each of the plurality of coils is capable of generating a canceling magnetic field when a feedback current is passed by using the electrode sections. The lead wire sections and the coil wire sections have crossing portions in which the lead wire sections and the coil wire sections are layered with an insulating section interposed so as to overlap each other in a winding axis direction of the coil wire sections.

Balance type current sensor

Magnetic detectors and a lower insulating layer covering the magnetic detectors are disposed on a substrate. On the lower insulating layer, a coil layer including a plurality of segments forming a counter detector of a feedback coil is disposed. Height adjustment layers are disposed on both sides of the coil layer. The coil layer and the height adjustment layers are covered with an upper insulating layer, and a shield layer is disposed thereon. Accordingly, the shield layer can be made substantially flat.

Current detection device

A current sensor includes a magnetic sensor module including a plurality of magnetic sensor units connected in series. The magnetic sensor units each include a first magnetic sensor element and a second magnetic sensor element which have sensitivity axes oriented in opposite directions. A first terminal of the first magnetic sensor unit is connected to a first potential source. A third terminal of the first magnetic sensor unit is connected to a second potential source. A second terminal and a fourth terminal of the last magnetic sensor unit are connected to constitute a sensor output terminal. The first terminal of each of the magnetic sensor units excluding the first magnetic sensor unit is connected to the second terminal of the next magnetic sensor unit and the third terminal thereof is connected to the fourth terminal of the next magnetic sensor unit.

Current sensor

A current sensor includes first and second magnetic sensors that are placed around a current line through which a current flows so that the current line is positioned therebetween, and that detect an induction field generated by the current. Each of the first and second magnetic sensors has a main sensitivity axis and a sub-sensitivity axis. The direction of the main sensitivity axis of each of the first and second magnetic sensors is oriented in a direction that is not orthogonal to the direction of the induction field. The directions of the main sensitivity axes of the first and second magnetic sensors are oriented in the same direction and the directions of the sub-sensitivity axes are oriented in the same direction, or the directions of the main sensitivity axes are oriented in opposite directions and the directions of the sub-sensitivity axes are oriented in opposite directions.

A current sensor includes a magnetoresistive element that has a stripe shape and that has a sensing axis in a certain direction. The magnetoresistive element includes element portions that are disposed so as to be spaced apart from each other in a longitudinal direction of the stripe shape, and permanent magnet portions, each of which is disposed between adjacent ones of the element portions. Each element portion has a layered structure including a free magnetic layer whose magnetization direction is changed with respect to an external magnetic field, a non-magnetic intermediate layer, and a ferromagnetic pinned layer whose magnetization direction is pinned. The permanent magnet portion includes a hard bias layer, and an electrode layer that is disposed so as to cover the hard bias layer.

A current sensor includes a substrate, a conductive body being provided above the substrate and extending in one direction, and magnetoresistance effect elements being provided between the substrate and the conductive body and outputting output signals owing to an induction magnetic field from a current to be measured being conducted through the conductive body, wherein each of the magnetoresistance effect elements has a laminated structure including a ferromagnetic fixed layer whose magnetization direction is fixed, a non-magnetic intermediate layer, and a free magnetic layer whose magnetization direction fluctuates with respect to an external magnetic field, the ferromagnetic fixed layer is a self-pinned type formed by antiferromagnetically coupling a first ferromagnetic film and a second ferromagnetic film through an antiparallel coupling film, the Curie temperatures of the first ferromagnetic film and the second ferromagnetic film are approximately equal, and a difference between the magnetization amounts thereof is substantially zero.

A current measurement apparatus includes multiple GMR elements and a calculation unit. The multiple GMR elements each include a pinned magnetic layer having a pinned magnetization direction, and a free magnetic layer having a magnetization direction to be changed by an external magnetic field. The calculation unit obtains the magnitude of a current to be detected, from outputs of the multiple GMR elements. The multiple GMR elements are disposed in ring shape around a conductor through which the current to be detected flows, and are electrically connected so as to form a series variable resistor by using the multiple GMR elements. The magnetization directions of the pinned magnetic layers are pinned in the same direction when viewed from an extension direction of the conductor at each of the positions of the elements.

Current measurement apparatus having a series of magnetoresistive effect elements disposed in a ring shape

A magnetic balance type current sensor includes a magnetic balance type current sensor including a magnetoresistance effect element whose characteristic changes owing to an induction magnetic field from a current to be measured flowing through a conductor, a feedback coil configured to be disposed in the vicinity of the magnetoresistance effect element and generate a cancelling magnetic field cancelling out the induction magnetic field, a magnetic shield configured to attenuate the induction magnetic field and enhance the cancelling magnetic field, and a hard bias layer configured to be provided on or above the magnetic shield.

Magnetic balance type current sensor

A current sensor including a magnetic detecting bridge circuit which is constituted of four magneto-resistance effect elements with a resistance value varied by application of an induced magnetic field from a current to be measured, and which has an output between two magneto-resistance effect elements. The four magneto-resistance effect elements have the same resistance change rate, and include a self-pinned type ferromagnetic fixed layer which is formed by anti-ferromagnetically coupling a first ferromagnetic film and a second ferromagnetic film via an antiparallel coupling film therebetween, a nonmagnetic intermediate layer, and a soft magnetic free layer. Magnetization directions of the ferromagnetic fixed layers of the two magneto-resistance effect elements providing the output are different from each other by 180&#xb0;. The magnetic detecting bridge circuit has wiring symmetrical to a power supply point.

A magnetic balance type current sensor includes a magnetoresistance effect element whose resistance value changes owing to the application of an induction magnetic field from a current to be measured; a feedback coil disposed in the vicinity of the magnetoresistance effect element and generating a cancelling magnetic field cancelling out the induction magnetic field; a magnetic field detection bridge circuit including two outputs causing a voltage difference corresponding to the induction magnetic field to occur; and a magnetic shield attenuating the induction magnetic field and enhancing the cancelling magnetic field, wherein, on the basis of the current flowing through the feedback coil at the time of an equilibrium state in which the induction magnetic field and the cancelling magnetic field are cancelled out, the current to be measured is measured, wherein the feedback coil, the magnetic shield, and the magnetic field detection bridge circuit are formed on a same substrate.

A magnetic-balance-system current sensor includes: a magnetoresistive element, a resistance value of the magnetoresistive element being changed by applying an induction magnetic field generated by a measurement target current; magnetic cores disposed near the magnetoresistive element; a feedback coil disposed near the magnetoresistive element and configured to generate a cancelling magnetic field that cancels out the induction magnetic field; and a magnetic-field detecting bridge circuit having two outputs. The measurement target current is measured on the basis of a current flowing through the feedback coil when the induction magnetic field and the induction magnetic field and the cancelling magnetic field cancel each other out. The feedback coil, the magnetic cores, and the magnetic-field detecting bridge circuit are formed on a same substrate. The feedback coil is of a spiral type, and the magnetic cores are provided above and below the feedback coil.

Magnetic-balance-system current sensor

A magnetic sensor includes a magnetoresistance effect element and a hard bias layer. The magnetoresistance effect element is configured to have a striped form which has a sensitivity axis in a predetermined direction, and configured to have a structure in which a free magnetic layer, in which magnetization varies with respect to an external magnetic field, a non-magnetic layer, and a fixed magnetic layer, in which the magnetization is fixed, are laminated. The hard bias layer is disposed in a longitudinal direction of the striped form, disposed outside of the magnetoresistance effect element to be separated from the magnetoresistance effect element.

Magnetic sensor and magnetic balance type current sensor including the same

A magnetic coupling type isolator includes: a magnetic field generator for generating an external magnetic field by an input signal; a magnetoresistive element for detecting the external magnetic field and converting the detected magnetic field into an electric signal, the magnetoresistive element being electrically insulated from the magnetic field generator and positioned in a location capable of being magnetically coupled so as to be overlapped with the magnetic field generator as seen in a top plan view; and first and second shield films overlapped with the magnetic field generator and the magnetoresistive element as seen in a top plan view, wherein a distance between the magnetoresistive element and the second shield film is set to 8 to 100 &#x3bc;m.

Magnetic coupling type isolator

A current sensor includes a magnetic detecting element, a bridge circuit including a plurality of resistance elements, and a feedback coil placed adjacent to the magnetic detecting element and generating a cancelling magnetic field for cancelling the induced magnetic field based on the output from the bridge circuit. The wiring patterns forming the bridge circuit are routed so as not to intersect with each other when seen in a plan view. Only the resistance elements constituting each series circuit of the bridge circuit are connected to each other by the wiring pattern in an enclosed area which encloses each resistance element constituting the bridge circuit, and the wiring pattern branched from the wiring pattern is connected to the terminal which is installed in a quantity of only one, outside the enclosed area.

Current sensor including magnetic detecting element

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Niigata-ken, Japan

Akira Takahashi