Linear displacement absolute position encoder

    公开(公告)号:US12078515B2

    公开(公告)日:2024-09-03

    申请号:US17904414

    申请日:2021-02-09

    IPC分类号: G01D5/16 G01D5/14

    CPC分类号: G01D5/16 G01D5/142

    摘要: Disclosed is linear displacement absolute position encoder used for measuring displacement of a tested apparatus. The linear displacement absolute position encoder comprises a base, a magnetoresistive sensor array, an encoding strip, and a back magnet. The encoding strip is fixed on the base and extends in the direction of a rail of the tested apparatus. The encoding strip is a magnetic material block having recess and protrusion for identifying encoding information of different positions. The magnetoresistive sensor array is arranged between the encoding strip and the back magnet in a non-contact manner. The back magnet is used for generating a non-uniform magnetic field around the encoding strip so as to magnetize the encoding strip. The magnetoresistive sensor array is used for acquiring the position encoding information of the encoding strip by detecting magnetic field information of the encoding strip. The encoder is low cost and can monitor large distances.

    Digital liquid level sensor utilizing cross-point magnetoresistive sensor array

    公开(公告)号:US12072226B2

    公开(公告)日:2024-08-27

    申请号:US17310912

    申请日:2020-02-26

    IPC分类号: G01F23/72 G01F23/68 G01R33/09

    摘要: A digital liquid level sensor based on a magnetoresistive sensor cross-point array includes tunnel magnetoresistance (TMR) magnetic sensor chips; a microcontroller electrically connected to a row decoder and a column decoder. The TMR magnetic sensor chips include magnetic tunnel junction (MTJ) elements. Diodes are connected between each row of MTJ elements and a row lead or a column lead. The TMR magnetic sensor chips are addressed using data decoded by the row decoder and the column decoder. The microcontroller is used for scanning addresses of the TMR magnetic sensor chips for the address of an MTJ element in the highest active state, converting the address value into a liquid level value in a linear proportional relationship therewith, and transmitting the liquid level value to an output interface. The power consumption of a sensor element is greatly minimized by powering only one sensor chip element each time.

    LASER WRITING APPARATUS AND METHOD FOR PROGRAMMING MAGNETORESISTIVE DEVICES

    公开(公告)号:US20240118317A1

    公开(公告)日:2024-04-11

    申请号:US18549104

    申请日:2022-03-02

    摘要: Disclosed in the embodiments of the present invention are a laser writing apparatus and method for programming magnetoresistive devices. The apparatus comprises: a substrate, a magnetoresistive sensor and a thermal control layer which are sequentially arranged in a stacked manner. A non-magnetic insulating layer for electrical isolation is provided between the magnetoresistive sensor and the thermal control layer. The magnetoresistive sensor is composed of a magnetoresistive sensing unit which is a multilayer thin-film stacked structure containing an anti-ferromagnetic layer. The laser writer programming apparatus is used during the laser writer programming phase, along with varied parameters of the thermal control layers and/or magnetoresistive sensors, to change the thermal gradient produced by the laser on the magnetoresistive sensor, to increase or decrease the temperature change of the magnetoresistive sensor at the same laser power, and the film parameters use d to do this include material composition and film thickness. Through the embodiments of this invention, high precision laser programming of a magneotresistive sensor is obtained, with improved magnetoresistive sensor manufacturability, improved magnetoresistive sensor noise performance, and with improved magnetoresistive sensor detectability.

    A TYPE OF ROTATING DISK MAGNETIC FIELD PROBE
    94.
    发明公开

    公开(公告)号:US20230273276A1

    公开(公告)日:2023-08-31

    申请号:US18000191

    申请日:2021-05-27

    IPC分类号: G01R33/09 G01R33/02

    摘要: A type of rotating disk magnetic field probe (1) comprising: a non-magnetic rotating disk (2), 4N first soft ferromagnetic sectors (3), M second soft ferromagnetic sectors (4), a reference signal generator, an X-axis magnetoresistive sensor (7, 8), a Y-axis magnetoresistive sensor (5,6), and a Z-axis magnetoresistive sensor (9). Both the first soft ferromagnetic sectors (3) and the second soft ferromagnetic sector (4) are located on the non-magnetic rotating disk (2). In operation, the non-magnetic rotating disk (2) rotates about a Z-axis at a frequency f. An external magnetic field is modulated by the first soft ferromagnetic sector (3) into an X-axis magnetic field sensed component and a Y-axis magnetic field sensed component having a frequency of 4N×f, and is modulated by the second soft ferromagnetic field sectors into a Z-axis magnetic field sensed component having a frequency of M×f. The X-axis sensed magnetic field component, the Y-axis sensed magnetic field component, and the Z-axis sensed magnetic field component respectively are converted into output signals by means of the X-axis magnetoresistive sensor (7, 8) the Y-axis magnetoresistive sensor (5, 6) and the Z-axis magnetoresistive sensor (9). The reference signal generator respectively outputs a first reference signal having a frequency of 4N×f and a second reference signal having a frequency of M×f. The first reference signal, the second reference signal, and the measurement signals are demodulated by an external processing circuit to output magnetic field values Hx, Hy and Hz.

    HIGH-SENSITIVITY MAGNETORESISTIVE ACOUSTIC WAVE SENSOR AND ARRAY DEVICE

    公开(公告)号:US20220397557A1

    公开(公告)日:2022-12-15

    申请号:US17753358

    申请日:2020-08-18

    发明人: Bin QI Songsheng XUE

    IPC分类号: G01N29/24 G01R33/09

    摘要: A magnetoresistive acoustic wave sensor with high sensitivity and an array device thereof is disclosed, in which a magnetoresistive acoustic wave sensor comprises a protective tube shell, a magnetic vibration assembly, and a magnetoresistive chip located inside the protective tube shell. The protective tube shell comprises at least one opening which is covered by the magnetic vibration assembly. The plane where the magnetoresistive sensor chip is located is perpendicular to the plane where the magnetic vibration assembly is located, and the sensing direction of the magnetoresistive sensor chip is located in the plane where magnetoresistive sensor chip is located, and is perpendicular to or parallel to the plane where the magnetic vibration assembly is located. Alternatively, the plane where the magnetoresistive sensor chip is located is parallel to the plane where the magnetic vibration assembly is located, and the sensing direction of the magnetoresistive sensor chip is located in the plane where the magnetoresistive sensor chip is located, and is parallel to the plane where the magnetic vibration assembly is located. The magnetoresistive acoustic wave sensor with high sensitivity and an array device thereof is of small size, high sensitivity, low power consumption, high response speed, good stable temperature, large response frequency bandwidth, excellent low-frequency response and the like.

    Magnetoresistive hydrogen sensor and sensing method thereof

    公开(公告)号:US11408949B2

    公开(公告)日:2022-08-09

    申请号:US17309266

    申请日:2019-11-13

    IPC分类号: G01R33/09 G01N27/04

    摘要: A magnetoresistive hydrogen sensor and sensing method thereof, wherein the hydrogen sensor comprises a substrate located in an X-Y plane, magnetoresistive sensing units and magnetoresistive reference units located on the substrate. The magnetoresistive sensing units are electrically connected to form a sensing arm, and the magnetoresistive reference units are electrically connected to form a reference arm. The sensing arm and the reference arm are electrically interconnected to form a referenced bridge structure. The magnetoresistive sensing units and the magnetoresistive reference units may be AMR units having the same magnetic multilayer thin film structure, GMR spin valves, or GMR multilayer film stacks having the same magnetic multilayer thin film structure. The magnetoresistive sensing units and the magnetoresistive reference units are respectively covered with a Pd layer, and a passivating insulation layer is deposited over the Pd layer of the magnetoresistive reference units. The magnetic multilayer thin film structure is made into a serpentine strip circuit by a semiconductor micromachining process. The hydrogen detecting method comprises placing the hydrogen sensor in a gas environment containing hydrogen, the Pd layers covering in the magnetoresistive sensing units absorb hydrogen to change the perpendicular magnetic anisotropy of ferromagnetic layers in the magnetic multilayer thin film structures of the magnetoresistance sensing units, which makes the magnetic moment of the ferromagnetic layer rotate to produce a change in the magnetoresistance value that correlates to the hydrogen concentration. The resulting change of the magnetoresistance value changes the output voltage value of the referenced bridge structure, and this change of the output voltage value of the referenced bridge structure is used to measure the hydrogen concentration.

    Resettable bipolar switch sensor
    97.
    发明授权

    公开(公告)号:US11300637B2

    公开(公告)日:2022-04-12

    申请号:US15733447

    申请日:2019-01-29

    IPC分类号: G01R33/09

    摘要: A resettable bipolar switch sensor is disclosed which comprises a bipolar magnetic hysteresis switch sensor, a reset coil, an ASIC switch circuit and a power reset circuit. The bipolar magnetic hysteresis switch sensor comprises a substrate and a magnetoresistive sensing arm located on the substrate. The magnetoresistive sensing arm is of a two-port structure composed of one or more magnetoresistive sensing unit strings arranged in series, parallel, or series-parallel. The magnetization direction of a free layer of a TMR magnetoresistive sensing unit is determined by an anisotropy field Hk, and together with the magnetization direction of a reference layer and the applied magnetic field, it can orient in an N or S direction. The reset coil is located between the substrate along with the magnetoresistive sensing unit, or it is located on a lead frame below the substrate. The direction of the reset magnetic field is either N or S. The ASIC switch circuit comprises a biasing circuit module, a reading circuit module, and an output circuit module. The power reset circuit is connected to the reset coil. This device has the advantages of low power consumption and small size in addition to the capability to set initial state of the switch sensor.

    NON-DESTRUCTIVE TESTING DEVICE FOR DETECTING DAMAGE TO STEEL WIRE ROPE

    公开(公告)号:US20210382007A1

    公开(公告)日:2021-12-09

    申请号:US17278037

    申请日:2019-09-17

    IPC分类号: G01N27/82 G01R33/00

    摘要: A non-destructive testing device for detecting damage to a steel wire rope, including a bushing which limits a lower shell and an upper shell through a limiting groove. The lower shell is connected to the upper shell via an opening and closing structure. An air bag is wrapped around the bushing. A PCB is fixed on the upper shell or the lower shell. The PCB is connected to a guide wheel via an electrical connector. A magnetoresistive sensor array is arranged inside the air bag and is uniformly arranged in a circumferential direction of the bushing. A steel wire rope passes through the magnetoresistive sensor array. And when the steel wire rope moves, it drives the guide wheel to rotate and triggers the acquisition of a command. Guide wheel is set with a position coder which is used to calculate a relative position of movement of the steel wire rope. The PCB is connected to a single chip microcomputer via a peripheral interface. And the single chip microcomputer is used to calculate a differential signal of N adjacent magnetoresistive sensors and to determine whether the steel wire rope is damaged. The capability of this non-destructive testing device for detection of a broken wire, a narrowed diameter, and deep damage of the steel wire rope is improved.

    Low-noise magnetoresistive sensor having multi-layer magnetic modulation structure

    公开(公告)号:US11067647B2

    公开(公告)日:2021-07-20

    申请号:US16608596

    申请日:2018-04-25

    IPC分类号: G01R33/09

    摘要: A low-noise magnetoresistive sensor includes a substrate and an array of magnetic modulation structures on the substrate. The structure includes upper and lower soft ferromagnetic layers and a conductive metal layer in the middle. The two ends of the structure are connected to form a two-port excitation coil. Adjacent structures have opposite current directions. A magnetoresistive sensing unit is located above or below and is centered in the gap between the structures. The sensitive direction of the sensing units is perpendicular to a long direction of the structures. An array of sensing units is electrically connected to form a magnetoresistive sensor, and the sensor is connected to the sensor bond pads. When measuring an external magnetic field, an excitation current is applied to the excitation coil, and the output of the voltage or current signal of the magnetoresistive sensor is demodulated to produce a low-noise voltage signal.

    Magnetoresistive angle sensor and corresponding strong magnetic field error correction and calibration methods

    公开(公告)号:US11022468B2

    公开(公告)日:2021-06-01

    申请号:US15545125

    申请日:2016-01-13

    发明人: James Geza Deak

    摘要: A biaxial magnetoresistive angle sensor with a corresponding calibration method for magnetic field error correction, comprising two single-axis magnetoresistive angle sensors for detecting an external magnetic field in an X-axis direction and a Y-axis direction that are perpendicular to each other, a unit for calculating a vector magnitude of the voltage outputs of the single-axis magnetoresistive angle sensors along the X axis and the Y axis in real time, a unit for calculating a difference between a known calibration vector magnitude and the measured vector magnitude, a unit for dividing the difference by the square root of 2 in order to calculate an error signal, a unit for adding the error signal to the X-axis output and the Y-axis output respectively or subtracting the error signal from the X-axis output and the Y-axis output in order to calculate the calibrated output signals of the X-axis and the Y-axis angle sensors, a unit for calculating an arc tangent of a factor obtained by dividing the calibrated Y-axis output signal by the calibrated X-axis output signal to provide a rotation angle of the external magnetic field. This method for applying the magnetic field error calibration to the biaxial magnetoresistive angle sensor reduces the measurement error and expands the magnetic field application range in addition to improving the measurement precision in a high magnetic field.