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87 results about "Magnetic impedance" patented technology
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Magnetic complex impedance [1, 2] is measured in units – [ ] and determined by the formula: where is the relationship of the effective or amplitude value of a magnetic tension and accordingly of the effective or amplitude magnetic current is called full magnetic resistance ( magnetic impedance ).
Magnetic recording medium and process for producing the same
InactiveUS20070231606A1Improve the overall coefficientHead contaminationMaterials with cobaltRecord information storageMetal powderCobalt
A magnetic recording medium comprising a substrate and a magnetic layer containing ferromagnetic metal powder and a binder, wherein the ferromagnetic metal powder contains iron, cobalt and form 2 to 20 atom % of yttrium based on a total of iron and cobalt contained in the ferromagnetic metal powder and has an average length of 50 nm or smaller, and the magnetic recording medium has a test value of at least 100 passes in a magnetoresistive head resistance reduction test performed as defined herein.
Owner:FUJIFILM CORP
Fault current limiter with saturated core
InactiveUS20120153927A1Lower overall pressure dropLower impedanceVariable inductancesVariable transformersEngineeringThree-phase
A three-phase current limiter (30) for an alternating current system includes an AC magnetic circuit having at least one AC coil (35R1, 35S1, 35T1) for each phase of a 3-phase AC supply wound on a saturable ferromagnetic core and configured to subject respective AC coils for each phase to a common magnetic flux, and a DC magnetic circuit (34a, 34b) for biasing the AC magnetic circuit into saturation at normal conditions. In use the AC coils are connected in series with a load and during alternate half cycles of the AC supply at least one of the AC coils produces a magnetic field that opposes a magnetic field of the DC magnetic circuit. The AC coils (35R, 35S, 35T) for each phase are configured so that at least one of the AC coils exhibits unbalanced magnetic impedance relative to remaining ones of the AC coils for each phase.
Owner:BAR ILAN RES & DEV +1
Full-tensor magnetic field gradiometer based on giant magnetic impedance effect
ActiveCN104062607AComprehensive measurementLow working environment requirementsMagnetic field measurement using flux-gate principleMagnetic field measurement using galvano-magnetic devicesMagnetic field gradientJunction point
The invention discloses a full-tensor magnetic field gradiometer based on the giant magnetic impedance effect. The full-tensor magnetic field gradiometer comprises an X-Y-direction gradiometer body, a Z-direction gradiometer body and signal leads. The X-Y-direction gradiometer body comprises a cross-shaped substrate and a giant magnetic impedance thin film, the Z-direction gradiometer body comprises a rectangular substrate and a giant magnetic impedance thin film, a junction point at the input end and a junction point at the output end of an electric bridge are connected with the signal leads, and the signal leads are arrayed symmetric with the geometric center of the whole gradiometer as the three-dimensional center. The full-tensor magnetic field gradiometer has the advantages of being high in accuracy, minimized, low in cost, wide in frequency response, rich in information and the like. Due to the design of preparing a three-dimensional structure through planar thin films, the problem of space consistency of the full-tensor magnetic field gradiometer based on the giant magnetic impedance thin films is solved, and the magnetic field gradient measuring sensor with the size at the chip level is designed for the first time.
Owner:BEIHANG UNIV
Current sensor and overload current protective device therewith
InactiveUS6984989B2Measurement using dc-ac conversionElectronic circuit testingNegative feedbackEnvironmental resistance
A small, low-cost, wide-range current sensor excellent in environmental resistance and noise resistance and high in accuracy, and an application device, a DC magnetic field is applied to two magnetic elements (1a, 1b) having a magnetic impedance effect by means of a magnet (3), while a negative feedback magnetic field is applied to both elements by means of a coil (2). The variation of the magnetic field depending on the external magnetic field applied to the magnetic elements (1a, 1b) is detected by detection units (7a, 7b). The difference between the output is amplified by a differential amplifier unit (8). Thus, detection is achieved in a wide range while eliminating the influence of the noise.
Owner:FUJI ELECTRIC FA COMPONENTS & SYST CO LTD
Device for measuring magnetic impedance
InactiveUS7759931B2Simple configurationSignal obtainedMagnetic property measurementsBurglar alarm electric actuationMeasurement deviceAudio power amplifier
The present invention relates to a magnetic impedance measurement device comprising an apply coil for generating an alternate magnetic field of variable frequency, a power source for the apply coil, at least one magnetic sensor means comprising a pair of magnetic sensors for detecting orthogonal vector components of a magnetic field generated from a test object, the vector components being parallel to the face of the apply coil, a measurement means for the magnetic sensor for measuring a detected signal from said magnetic sensor mean, the measurement means being located at a distance from the face of the apply coil and facing the test object, a lock-in amplifier circuit for detecting from an output of the measurement means a signal having the same frequency as the frequency of the apply coil and an analysis means for analyzing intensity and phase changes of an output of the magnetic sensor means with the use of an output signal of the lock-in amplifier circuit.
Owner:NATIONAL UNIVERSITY
Magnetic sensor
InactiveCN1513119ALow costReduce detection accuracyGalvano-magnetic devicesSolid-state devicesNegative feedbackMagnetic reluctance
Provided is a magnetism detection apparatus that is small and low in cost and power consumption, a biasing coil 4 and a negative-feedback coil are integrated with a magnetic impedance element having a magnetic impedance effect in a resinous structure. The magnetism detection apparatus has a reduced magnetic resistance between the magnetic impedance element and the coil, thereby making it possible to apply a bias magnetic field and a negative-feedback magnetic field to the magnetic impedance element with a reduced power consumption.
Owner:FUJI ELECTRIC FA COMPONENTS & SYST CO LTD
Strong magnetic impedance magnetic field sensor
InactiveCN1794003ASolve the giant magneto-impedance rate of changeResolve detectionMagnetic measurementsMagnetic-field-controlled resistorsCapacitanceTransducer
A transducer of giant magnetic impedance field is prepared as applying transistor with cut ¿C off frequency of 3 ¿C 60 MH2 as kerr magnetic oscillation circuit, applying the same resistance value on two voltage ¿C dividing resistances between base electrode and ground as well as between base electrode and DC power supply, series ¿C connecting crystal oscillator with frequency of 1¿C 20 MH2 with vibration starting capacity between base electrode and ground, existing noncrystalling belt as part of radio electrode load.
Owner:ZHUHAI COLLEGE OF JILIN UNIV
Rapid de-excitation system for synchronous machines with indirect excitation
InactiveUS20110298430A1Good dynamic responseImprove securitySynchronous generatorsGenerator control by field variationControl circuitElectrical impedance
The invention relates to a rapid deexcitation system for synchronous machines (1) with indirect excitation by means of an excitation machine (2) and rotating rectifier bridge (8) comprising:a deexcitation impedance (10) connected between the field winding (5) of the synchronous machine (1) and the rotating rectifier bridge (8);a controller (9) connected in parallel with the deexcitation impedance (10);a control circuit (11) of the controller (9) configured to:keep the controller (9) closed such that the rotating rectifier bridge (8) directly feeds the field winding (5) of the synchronous machine (1) during normal operation of the synchronous machine (1);open the controller (9) such that the deexcitation impedance (10) remains in series with the field winding (5) and with the rotating rectifier bridge (8) when the synchronous machine is to be deexcited.
Owner:UNIV MADRID POLITECNICA
Current sensor and overload current protective device comprising the same
InactiveCN1491360ACurrent/voltage measurementElectrodynamic magnetometersNegative feedbackEnvironmental resistance
A small, low-cost, wide-range current sensor excellent in environmental resistance and noise resistance and high in accuracy, and an application device, a DC magnetic field is applied to two magnetic elements (1a, 1b) having a magnetic impedance effect by means of a magnet (3), while a negative feedback magnetic field is applied to both elements by means of a coil (2). The variation of the magnetic field depending on the external magnetic field applied to the magnetic elements (1a, 1b) is detected by detection units (7a, 7b). The difference between the output is amplified by a differential amplifier unit (8). Thus, detection is achieved in a wide range while eliminating the influence of the noise.
Owner:FUJI ELECTRIC CO LTD
Overload current protection device using magnetic impedance element
InactiveUS7085116B2Galvano-magnetic devicesAc-dc conversion without reversalControl powerEngineering
In an overload current protection device for cutting off power from a power supply to a load (3) such as a motor by means of a contactor (switch) (2) at overloading, an MI element having a magnetic impedance (MI) effect as current detectors (4a, 4b, and 4c) is installed at a position capable of detecting a current flowing through the secondary winding of power supply transformers (5a, 5b, and 5c) that generate a control power supply to thereby reduce costs without using a constant voltage power supply and expand a current detection range by eliminating magnetic saturation due to a core, a problem with a conventional current transformer, thereby providing at low costs a high-precision overload current protection device having a wide current detection range.
Owner:FUJI ELECTRIC CO LTD
Overload current protection apparatus
InactiveUS7031131B2Increase rangeWide applicabilityEmergency protection detectionEmergency protection for supplying operative powerCurrent sensorPeak value
A current sensor which constitutes an overload protection apparatus and senses a current supplied from a power source to a load is constituted by providing a magnetic sensor having the effect of magnetic impedance (MI), an AC supply means which impresses AC on this sensor, a bias current supply means which supplies a bias current to a bias coil, a peak sensing means which senses the peak or a change in impedance of the magnetic sensor as a change in voltage, and a switch which selects the output of the peak sensing means in accordance with each phase. A holding means which holds switch outputs one after another and an amplification means are provided in common to enable current sensing for each phase. Thus, a range of current sensing is enlarged to reduce power consumption and cost.
Owner:FUJI ELECTRIC FA COMPONENTS & SYST CO LTD
Method for manufacturing magnetosensitive device with giant magnetic impedance effect based on microelectrochenical system
InactiveCN1694276AHigh sensitivityImprove response speedMagnetic measurementsDecorative surface effectsHigh volume manufacturingEtching
This invention relates to a manufacturing method for a huge magnet impedance effect magnet-sensitive device based on micro-electromechanical system (MEMS), which applies MEMS technology to process a double-face oxidized silicon chip to get an aligned symbol carved in double faces so as to increase the aligned accuracy when exposing, applies a quasi-LIGA photo etching technology and micro plating to prepare a zigzag sandwich structure FeNi / Cu / FeNi soft magnet multiplayer membrane material, applies physical etching to remove the substrate to avoid the erosion brought with wet etching and offsets the huge magnet impedance effective curves by selecting suitable magnets to make the magnet-sensitive device to work in the linear zone.
Owner:SHANGHAI JIAO TONG UNIV
Magnetic field detection circuit using magnetic impedance device
InactiveUS6897649B2Low costSimple configurationGalvano-magnetic devicesSolid-state devicesPulse shapingSimple circuit
A magnetic field detection circuit comprises a magnetic impedance device, a detection coil wound around or arranged close to the impedance device, an electric current application circuit for applying a pulse-shaped high frequency electric current substantially equally swinging to the positive side and the negative side to the magnetic impedance device, and a detection circuit for detecting a voltage generated in the detection coil in response to rises and falls of the applied pulse-shaped electric current and outputting a signal corresponding to the intensity of the external magnetic field on the basis of the outcome of the detection. The magnetic field detection circuit can provide nil-point setting on a stable basis by means of a simple circuit arrangement at low cost.
Owner:CANON DENSHI KK
Magnetic induction tomography systems with coil configuration
A magnetic impedance tomography system comprises an excitation system with several excitation coils to generate an excitation magnetic field to induce eddy currents in an examination volume. For example, a solenoid configuration or parallel coils, e.g. in a Helmholtz configuration are employed, Further, a measurement system is provided with several measurement coils to measure the fields generated by the induced eddy currents. The measurement coils are arranged in a volumetric (3D) geometrical arrangement. The individual measurement coils being orientated substantially transverse to the field line of the excitation magnetic field of the excitation coils. A reconstructor receives measurement data from the measurement system and reconstruct an image of an object in the volume of interest from the measurement data.
Owner:KONINKLIJKE PHILIPS ELECTRONICS NV
System and method for corrosion diagnosis of grounding grid of transformer substation on the basis of inductive apparent magnetic impedance method
InactiveCN107748198AAvoid electromagnetic interferenceReliable measurement dataMaterial magnetic variablesTransformerLabview software
Owner:STATE GRID CORP OF CHINA +2
Magnetic field detecting device
ActiveUS20150219731A1Improve accuracyLow production costMagnitude/direction of magnetic fieldsAlternating currentVoltage source
A magnetic field detecting device which comprises a magnetic impedance sensor including a magnetic impedance element 1 in which a pulse electrical current or a high frequency electrical current is applied from an oscillator 2 to an amorphous wire 10 and an alternate current or AC damped oscillation voltage, which is induced in a detecting coil 11 wound around the amorphous wire 10 and has a magnitude corresponding to an external magnetic field, is output, and an arbitrary magnetic field is applied to the amorphous wire by means of the magnetic field generated on the detecting coil 11 energized by connecting the detecting coil 11 to a voltage source or to a current source E through an impedance network 3 comprising of a resistor R or a coil L or a condenser C or comprising a combination of the resistor R, the coil L, and the condenser C.
Owner:AICHI STEEL
System and method of detecting ultra weak magnetic field
ActiveUS20150212164A1Highly sensitivelyAccurate detectionMagnetic field offset compensationMagnetic field measurement using flux-gate principleFall timeSignal on
According to one exemplary embodiment, a system of detecting magnetic field comprises a magnetic impedance element surrounded by a detection coil, a stimulus unit generates pulse signal of programmable rise / fall time to drive the magnetic impedance element, and a signal detection module detects signal on the detection coil, wherein the signal detection module includes a buffer unit having adjustable bandwidth shapes output signal of the detection coil, a signal amplify unit includes a sample and hold circuit and a chopping programmable gain amplifier to amplify buffered signal from the buffer unit, a signal processing unit processes amplified signal from the signal amplify unit by applying selectable algorithm to output detection result, and a control unit connects the signal processing unit to generate control parameters of the stimulus unit, the buffer unit, the signal amplify unit, and the signal processing unit.
Owner:PROLIFIC TECH INC
Magnetic sensor
InactiveUS6879153B2DetectionReduce detectionGalvano-magnetic devicesSolid-state devicesNegative feedbackEngineering
To provide a magnetism detection apparatus that is small and low in cost and power consumption, a biasing coil 4 and a negative-feedback coil are integrated with a magnetic impedance element having a magnetic impedance effect in a resinous structure. The magnetism detection apparatus has a reduced magnetic resistance between the magnetic impedance element and the coil, thereby making it possible to apply a bias magnetic field and a negative-feedback magnetic field to the magnetic impedance element with a reduced power consumption.
Owner:FUJI ELECTRIC FA COMPONENTS & SYST CO LTD
Magnetosensitive device based on soft magnetic multilayer film giant magnetic impedance effect
InactiveCN1694275AGood repeatabilityLow costMagnetic measurementsMagnetic-field-controlled resistorsHigh volume manufacturingSoft magnet
This invention relates to a huge magnetic impedance effect magnet-sensitive device based on a soft magnet multiplayer membrane composed of a SiO2 substrate, pins, a zigzag sandwich structure soft magnet multiplayer membrane and an offset magnet, among which, the pins are led out from the copper layers at both ends of the multiplayer membrane and set on the substrate, the entire multiplayer membrane is placed on the substrate. The offset magnet is prepared with fine process technology and adhered on the back of the device with epoxy glue.
Owner:SHANGHAI JIAO TONG UNIV
Stress-torsion magnetic impedance integration test device of metal fiber
ActiveCN104865540AEasy to controlReduce the impactMagnetic property measurementsCombined testHelmholtz coil
The invention relates to a stress-torsion magnetic impedance integration test device of a metal fiber and aims at solving a problem that a test can not be directly and effectively performed in the prior art. The device comprises an integration test platform and an attached magnetic field generation apparatus. Integration test platform matching is used for collecting a four-terminal magnetic impedance test and analysis system of metal fiber impedance to be tested in the platform and magnetic field calibration and monitoring system. The magnetic field generation apparatus comprises a Helmholtz coil and a direct-current power supply which matches with and is connected to the coil. The integration test platform is a stress-free torsion platform which exerts torsion on the metal fiber to be tested or a stress-torsion combined platform used for exerting the stress and the torsion on the metal fiber. The magnetic field calibration and monitoring system comprises a single axis magnetometer and a probe arranged on one side of the torsion platform. An axial direction of the probe is parallel to an axial direction of the Helmholtz coil and an axis is parallel to and is consistent with a height of the metal fiber. The device has the following advantages that it is convenient to replace the test platform; the stress and torsion control is accurate; and the fiber is not easy to break and kink.
Owner:INNER MONGOLIA UNIV OF TECH
Non-invasive monitoring of blood metabolite levels
Solutions for non-invasively monitoring blood metabolite levels of a patient are disclosed. In one embodiment, the method includes: repeatedly measuring a plurality of electromagnetic impedance readings with a sensor array from an epidermis layer of a patient and one of a dermis layer or a subcutaneous layer of the patient, until a difference between the readings exceeds a threshold; calculating an impedance value representing the difference using an equivalent circuit model and individual adjustment factor data representative of a physiological characteristic of the patient; and determining a blood metabolite level of the patient from the impedance value and a blood metabolite level algorithm, the blood metabolite level algorithm including blood metabolite level data versus electromagnetic impedance data value correspondence of the patient.
Owner:BIOSENSOR INC
Electromagnetic impedance spectroscopy apparatus and related planar sensor system
ActiveUS20200408708A1High strengthMinimally modifiedMaterial impedanceMaterial capacitanceMaterial under testSensor system
According to various implementations, an apparatus for electromagnetic impedance spectra graphic characterization of a material under test (MUT) includes: a planar array of at least two electrodes configured to be placed in electromagnetic communication with the MUT, wherein during operation of the planar array, at least one of the electrodes comprises a transmitting electrode for transmitting an electromagnetic signal over a range of frequencies through the MUT to at least one receiving electrode in the planar array; and a backer ground plate at least partially surrounding the at least two electrodes, the backer ground plate being electrically grounded and insulated from the at least two electrodes, wherein the backer ground plate extends from a plane formed by the at least two electrodes and separates the at least two electrodes to create an electrically isolated volume proximate to the at least two electrodes.
Owner:TRANSTECH SYST
Overload current protection device using magnetic impedance element
An overload current protection device for cutting off power applied from a power supply to a load (3) such as a motor by means of a contactor (switch) (2) at overloading. With the configuration, an element (40) having a magnetic impedance effect as current detection units (4a, 4b, 4c) is used to thereby expand a current detection range by eliminating magnetic saturation due to a core, a problem with a conventional current transformer, thereby providing at low costs an overload current protection device having a wide current detection range.
Owner:FUJI ELECTRIC FA COMPONENTS & SYST CO LTD
Over-current protection device
InactiveUS20060072272A1Prevent magnetic saturationIncrease rangeEmergency protection detectionEmergency protection for supplying operative powerAudio power amplifierPeak value
An over-current protection device is constituted of a current detection unit for detecting a current from a power-supply source to a load having a magnetism detection element with a magnetic impedance (MI) effect, an AC-current supply device for supplying an AC current to the detection element, a bias-current supply device for supplying a bias current to a bias coil, a peak detection device for detecting a peak of impedance of the magnetism detection element as a variation of voltage, and a switch corresponding to a phase for selecting an output of the peak detection device. In the current detection unit, a holding device for holding a switch output and an amplifier are disposed in common for detecting the current in each phase, thereby expanding a current detectable range and reducing power consumption and cost.
Owner:FUJI ELECTRIC FA COMPONENTS & SYST CO LTD
Compressor and method of using compressor
InactiveUS7785079B2Compact and inexpensive structurePump parameterPump controlElectromagnetic clutchDrive shaft
A compressor of the present invention is provided with a plurality of housing members (a front housing, a cylinder block, and a rear housing) that forms a body, a fastener (a bolt member) for coupling the plurality of the housing members to one another, a drive shaft inserted through the body and coupled to a power source via an electromagnetic clutch, a movable member (a piston) that moves in association with the drive shaft to compress a fluid, a detection body that moves in association with the drive shaft, and a detection part for detecting a rotational state of the drive shaft by means of the detection body. A magnetic sensor having a magnetic impedance element constitutes the detection part. The magnetic sensor is provided on an outer lateral face side of the body and in proximity to the fastener.
Owner:TOYOTA BOSHOKU KK +1
Apparatus and methods for determining electrical conductivity of tissue
Owner:UNIV OF SHEFFIELD
Magnetic impedance device, sensor apparatus using the same and method for manufacturing the same
InactiveUS20070108970A1Minimal sizeReduce manufacturing costMagnetic-field-controlled resistorsSolid-state devicesMagnetic reluctanceAlternating current
A magnetic sensor apparatus includes a semiconductor substrate and a magnetic impedance device for detecting a magnetic field. The magnetic impedance device is disposed on the substrate. The magnetic sensor apparatus has minimum size and is made with low manufacturing cost. Here, the magnetic impedance device detects a magnetic field in such a manner that impedance of the device is changed in accordance with the magnetic filed when an alternating current is applied to the device and the impedance is measured by an external electric circuit.
Owner:DENSO CORP
Compressor
InactiveUS20080159878A1Compact and inexpensive to manufactureReduce manufacturing costPump parameterPump controlElectromagnetic clutchDrive shaft
This compressor includes housing members that form a body; a drive shaft linked to a drive power source via an electromagnetic clutch; movable members moving in cooperation with the drive shaft and carrying out the compression of a fluid; a detected body moving in cooperation with the drive shaft; a drain bolt screwed into a drain bolt hole provided in a housing member in proximity to the detected body; and a detecting device detecting the rotation state of the drive shaft by the detected body. The drain bolt is provided with a permanent magnet, the detecting device is structured by a magnetic sensor that includes a magnetic impedance element, and the magnetic sensor is provided at the head portion of the drain bolt. Thereby, it is possible to provide a rotation detecting mechanism by using an existing drain bolt, without requiring the machining of a hole in the compressor body.
Owner:TOYOTA BOSHOKU KK
Giant magnet impedance effect composite wire with barrier layer and its preparing method
InactiveCN1555048AIncrease the cross-sectional areaSimple preparation processMagnetic measurementsManufacture of flux-sensitive headsMetalMagnetic impedance
The present invention relates to composite wire with barrier layer possessing giant magnetic impedance effect, and belongs to the fields of magnetic sensing, storing and information functional material and the preparation technology. The composite wire consists of metal wire, barrier layer and soft magnetic layer. The barrier layer of insulating material is attached to the surface of the metal wire, and the soft magnetic layer of GMI soft magnetic material is attached to the surface of the barrier layer. The preparation process includes painting barrier layer onto the metal wire, chemically plating the soft magnetic layer onto the barrier layer, and annealing. The composite wire with giant magnetic impedance effect has simple preparation process, relatively high giant magnetic impedance effect and low work frequency and may be used in device conveniently and reliably.
Owner:EAST CHINA NORMAL UNIV
Array giant magnetic impedance effects current sensor
InactiveCN101038305BImprove linearityImprove signal-to-noise ratioCurrent/voltage measurementAudio power amplifierSignal-to-noise ratio (imaging)
The present invention pertains to the field of current measuring device, and especially relates to a un-contact type sensor measuring the current by generating the change of the magnetic field throughthe current based on the Giant Magnetic Impedance (GMI) effect. Said sensor consists of an array type un-crystal GMI current sensor probe heads (1) and (2), a periodic circuit (3), a rectification circuit (4), a subsequent zeroing amplifier (5) and a digital display unit (6); the array type un-crystal GMI current sensor probe heads (1) and (2) are formed by welding a plurality of quadrate un-crystal band units (8) with good property of soft magnetism by the copper wires arranged in series and the two array type probe heads (1) and (2) which have a same requirement are laid on the two sides ofthe lead (10) for electrifying. The device has a differential type structure of two probe heads, and can amplify the signals and improve the signal to noise ratio and the degree of the linearity of the output curve; the device has a small structure and a high sensitivity and is economical and practical; the device can be used widely in each production and research field for the measuring of the current.
Owner:JILIN UNIV
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