244 results about "Magnetoresistive sensor" patented technology

The invention provides an electrical equipment remote maintenance guidance method and system. The method comprises the following steps: capturing an aperiodic torque waveform and a magnetic field gradient abnormal signal by deploying a torque fluctuation sensor and a magnetoresistive sensor; performing multi-scale frequency band division on the non-periodic torque waveform, screening out a transient high-frequency component in a start-stop stage of equipment, and separating out a magnetic field polarity reversal characteristic from a magnetic field gradient abnormal signal; performing cross-domain matching on the occurrence time of the transient high-frequency component and the spatial orientation of the magnetic field polarity reversal feature to generate a mixed feature mark; calculating a frequency band overlapping degree based on the time-frequency energy distribution marked by the mixed features and generating a coherence map; and matching a fault historical case library according to the coherence map, and outputting a maintenance strategy set aiming at the rotating shaft dynamic unbalance and electromagnetic interference superposition fault. According to the invention, through fusion of torque fluctuation and magnetic field distortion collaborative analysis, the precision of mechanical and electromagnetic composite fault diagnosis of the rotating shaft is improved.

The invention discloses a high-sensitivity detection method for the safety of a battery cell, and the method comprises the following steps: S1, collecting the data of the battery cell in real time through a tunnel magnetoresistive sensor, and outputting a preliminary detection data set; s2, generating a micro-short circuit risk identification signal based on the preliminary detection data set; s3, generating a temperature anomaly distribution map by using the preliminary detection data set; s4, generating a thermal runaway early warning signal based on the temperature anomaly distribution map; s5, performing magnetic field scanning on the pole piece to generate a magnetic distortion data atlas; s6, constructing battery cell multi-source detection data, inputting the data into the physical information neural network, and training to obtain a final battery cell aging evolution model; s7, outputting a charging and discharging strategy optimization instruction based on the final cell aging evolution model; and S8, uniformly fusing the micro short circuit risk identification signal, the thermal runaway early warning signal and the charging and discharging strategy optimization instruction to generate a comprehensive response control instruction. According to the method, magnetic resistance sensing and physical modeling are fused, and intelligent prediction and response control optimization of the risk of the battery cell are realized.

The invention discloses a molded case circuit breaker short-circuit fault positioning method, and the method comprises the steps: obtaining the current differential response data of all branches of a molded case circuit breaker control loop when a short-circuit fault occurs based on a magnetoresistive sensor, obtaining a first data set, analyzing the first data set, and extracting the wavefront features of each branch; wavefront arrival time is obtained based on wavefront features, the first data set is input into a wave velocity calibration model to obtain frequency-dependent wave velocities of all branches, and the wavefront arrival time and the frequency-dependent wave velocities are input into a short-circuit fault positioning model to obtain space coordinates of fault points; and carrying out confidence evaluation on the fault point space coordinates to obtain an evaluation result, and judging whether to send the fault point space coordinates to a terminal user based on the evaluation result. The current differential response data is obtained based on the magnetoresistive sensor, the wavefront features are extracted, the frequency-varying wave velocity calibration and path compensation optimization model is combined, the problems of insufficient signal capture, wave velocity modeling deviation and low time difference detection precision in a traditional method are solved, and the short-circuit fault positioning method has the advantage of improving the short-circuit fault positioning precision and reliability.

The invention provides a fault positioning method and system for an overhead line of a power distribution network, and a storage medium. The method comprises the steps of obtaining a plurality of fault traveling wave magnetic field signals; performing the following steps on any signal: performing phase-mode transformation on the signal, extracting and decomposing a line mode component, determining a modulus maximum point, and determining the time corresponding to the point as a first fault traveling wave head arrival moment; carrying out clock synchronization on the moment, and obtaining a wave head arrival moment of a second fault traveling wave; obtaining a to-be-detected fault point and a line parameter; based on the wave head arrival moments of the plurality of second fault traveling waves, extracting a head end arrival moment and a tail end arrival moment; and performing fault positioning on the overhead line of the power distribution network based on the head end arrival time, the tail end arrival time and the fault line parameters. According to the fault positioning method for the overhead line of the power distribution network, interference to normal operation of the power distribution network can be avoided, and high-precision non-intrusive positioning of the overhead line of the power distribution network is realized through the tunneling magnetoresistive sensor.

The invention provides a self-calibration method of a TMR (Tunnel Magnetoresistive) sensor and a TMR sensor array for current measurement, and relates to the technical field of quantum current sensors. According to the method, a double Wheatstone bridge structure is adopted, a to-be-measured bridge is used for measuring a to-be-measured magnetic field, and a reference bridge is used for measuring a known reference magnetic field; the self-calibration of the TMR sensor is realized by calculating the ratio of the output voltages of the two bridges, so that measurement errors caused by environmental factors such as temperature, humidity and mechanical vibration are eliminated; moreover, the invention provides a TMR sensor array for current measurement, the application of the TMR sensor array further enhances the adaptive capacity of the TMR sensor array in a complex environment, and the array is formed by a plurality of TMR sensor units, so that not only can the spatial resolution of measurement be improved, but also the fault-tolerant capability of the system can be improved through redundancy configuration, and the system reliability is improved. The array structure enables the TMR sensor to perform accurate measurement at a plurality of measurement points at the same time to obtain accurate measurement current.

The invention relates to a current measurement method and device, computer equipment, a storage medium and a program product. The method comprises the following steps: acquiring the magnetic field intensity of the two sides of a monitoring point at the current moment through a first magnetoresistive sensor and a second magnetoresistive sensor which are deployed on the two sides of the same monitoring point of a power transmission line to obtain first magnetic induction intensity and second magnetic induction intensity; wherein the first magnetoresistive sensor and the second magnetoresistive sensor are located in the same electromagnetic environment; according to the first magnetic induction intensity, the second magnetic induction intensity and the error coefficient of the first magnetoresistive sensor and the second magnetoresistive sensor, the initial current value of the monitoring point at the current moment is determined, and the influence of the hysteresis effect on the current value is eliminated; and Kalman filtering processing is carried out on the initial current value of the monitoring point at the current moment to obtain the target current value of the monitoring point at the current moment, so that the accuracy of the measured current value is further improved.

The invention relates to a gamma sector distinguishing method for a near-bit, and relates to the technical field of oil-gas exploration and development. According to the method provided by the embodiment of the invention, the angular difference problem of the near-bit instrument is automatically processed through the processing of the initial angular difference, the free configuration of the angular difference is realized, and if the mounting position is changed, the trouble in the dismounting process can be reduced. And the difference value between the gravity tool face and the magnetic tool face is collected through an external pump stopping signal to serve as the calibration offset. Meanwhile, the theory that the components of the magnetoresistive sensor in the positive and negative directions of the standard magnetic field are opposite numbers is used, and a certain magnetoresistive component is linear accumulation of all axial components in the standard magnetic field. And respectively corresponding component coefficients can be calculated through composite operation between standard positions. The calibration precision is improved, errors caused by component differences or component installation errors in the installation and debugging process are reduced, the influence on the magnetic tool face is reduced, and the linearity and precision of the tool face are improved.

A signal processing circuit for a tunneling magnetoresistance sensor comprises thirty-eight MOS transistors, two capacitors and ten switches. A first switch, a second switch, a third switch, a fourth switch, a first MOS transistor, a second MOS transistor, a third MOS transistor and a fourth MOS transistor form a high-frequency modulation circuit. A fifth switch, a sixth switch, a seventh switch, an eighth switch, a seventeenth transistor, a twenty-second MOS transistor and a twenty-third MOS transistor form a high-frequency demodulation circuit. A signal output by a tunneling magnetoresistance sensor is modulated to a chopping frequency by the high-frequency modulation circuit, and is then demodulated by the high-frequency demodulation circuit.

A point-of-care device and method for simultaneously and quantitatively assessing a magnetically-labelled analyte immobilised on a lateral flow test strip are provided. The method comprises the steps of sensing a magnetic signal from the magnetically-labelled analyte on the test strip and converting the magnetic signal into an electric signal; processing the electric signal to obtain a quantitative value of the amount of analyte; and processing the values to provide a differential assessment between the magnetically-labelled analyte. The device includes a magnetic reader with at least one magnetic sensor, such as a giant magnetoresistive sensor. The magnetic sensor can be directly or indirectly coupled to a lock-in amplifier configured to perform phase-sensitive detection and enhance the signal-to-noise ratio of weak magnetic signals. A system, microfluidics device, lateral flow immunoassay test strip and kit are also provided.

The invention discloses an AMR magnetoresistive sensor, and mainly solves the technical problem that the detection precision of an existing AMR sensor is easily affected by an external interference magnetic field. Each bridge arm of the Wheatstone bridge is correspondingly connected with a magnetoresistive element in series, and the angle difference of the magnetization directions of the magnetoresistive elements at the adjacent bridge arms is within the range of 180 + / -delta degrees. According to the AMR sensor, the anti-ferromagnetic layer is arranged, and the shape of the anti-ferromagnetic layer is the same as that of the magnetoresistive effect layer, so that compared with an existing AMR sensor, a tedious and complicated exposure process can be omitted, and the purpose of simplifying the process is achieved. And the magnetization directions of the magnetoresistive elements at the adjacent bridge arms in the sensor bridge circuit are basically opposite, so that adverse effects caused by an interference magnetic field can be counteracted when the external interference magnetic field exists, the sensitivity of the sensor is prevented from being greatly changed, and the magnetic field measurement accuracy of the sensor is ensured.

The invention provides an absolute position magnetic encoder, which comprises a double-track vernier code disc, the double-track vernier code disc comprises an inner track code disc and an outer track code disc which are concentrically arranged, the inner track code disc comprises n pairs of magnetic poles which are annularly arranged, the outer track code disc comprises m pairs of magnetic poles which are annularly arranged, m-n = 1, n is a positive integer, n is a positive integer, n is a positive integer, n is a positive integer, and n is a positive integer. The first tunneling magnetoresistive sensor corresponds to the inner rail coded disc, so that the first tunneling magnetoresistive sensor obtains the magnetic field change of the inner rail coded disc; and the second tunneling magnetoresistive sensor corresponds to the outer rail coded disc, so that the second tunneling magnetoresistive sensor obtains the magnetic field change of the outer rail coded disc. According to the absolute position magnetic encoder provided by the invention, the absolute position of the tunneling magnetoresistive sensor on the double-track vernier code disc can be determined by using the magnetic pole phase difference between the inner track code disc and the outer track code disc.

The invention discloses a low-noise, high-precision and low-power-consumption tunnel magnetoresistance array type magnetic anomaly detection device, and relates to the field of geomagnetic field magnetic anomaly detection. In order to overcome the defects that in the prior art, the detection precision is insufficient, the noise level is high, power consumption is large, and long-time stable operation is difficult to consider, the technical scheme provided by the invention is that a signal acquisition and amplification circuit is composed of a plurality of triaxial tunnel magnetoresistive sensors, an isolation circuit, an instrument amplification circuit and a passive filter circuit; the master control and signal processing circuit is composed of a high-precision analog-to-digital conversion circuit, a clock circuit and a microprocessor circuit. The signal transmission circuit is composed of an Ethernet module and is used for transmitting the processed data to an upper computer; the power supply module is composed of a low-noise low-dropout voltage stabilizing circuit and a reference voltage circuit, and is used for providing a stable power supply and a unified reference voltage. The method is suitable for long-time high-precision geomagnetic anomaly detection work in geophysical exploration, national defense safety monitoring and complex environments.

The invention discloses a current sensor structure based on tunnel junction magnetoresistance and a manufacturing method, the current sensor structure comprises a first array group and a second array group, and the first array group and the second array group are composed of a first tunnel junction magnetoresistance array unit and a second tunnel junction magnetoresistance array unit which are arranged along the same sensing direction, and a first electrode unit and a second electrode unit; the sensitive axis directions of the first array group and the second array group are opposite to each other, and the second array group rotates by 180 degrees relative to the first array group in the physical space and then is in cross connection through metal electrodes. The tunnel junction magnetoresistive sensor has the beneficial effects that the tunnel junction magnetoresistive sensor comprises the first array group and the second array group, and the first tunnel junction magnetoresistive array unit and the second tunnel junction magnetoresistive array unit in the first array group and the second array group respectively comprise eight arrays, so that the tunnel junction magnetoresistive sensor has higher physical reliability and stability; the measurement error of the tunnel junction magnetoresistive sensor caused by the magnetic field gradient can be reduced; when the magnetic field and the current are measured, the magnetic field with the magnitude as low as 17 nT / Hz can be measured.

The invention provides a chest drainage amount data display method and device, electronic equipment and a storage medium, and the method is characterized in that magnetoresistive sensor groups are arranged on two opposite sides outside a drainage bottle, a height data group of a magnetic floating ball is obtained through the magnetoresistive sensor groups, and an inclination angle is calculated; the chest drainage data at each moment is directly calculated according to the height data set at each moment and is displayed at the first frequency, the display accuracy and timeliness of the chest drainage data can be ensured, when the inclination angle is larger than the preset angle, the height data sets at n continuous moments are firstly taken, then m target height data sets are selected, and the target height data sets are displayed at the same time. The chest drainage volume data is calculated on the basis and displayed at the second frequency, calculation errors caused by the fact that single-point value taking is affected by shaking can be solved, display jumping caused by frequent change of the drainage volume data can be relieved, and display of the chest drainage volume data is more accurate through integration of the two.

The invention provides a Hall circuit and a Hall chip, which are applied to the technical field of electromagnetic signals. According to the invention, the switch module can be in a continuous opening state, so that the magnetic induction intensity of a surrounding magnetic field can be detected and the working state of the linear Hall sensor can be controlled in real time; as the switch module only needs to realize the functions of detecting the magnetic induction intensity of the surrounding magnetic field in real time and starting the linear Hall sensor switch, the resistance value of the magnetoresistive sensor of the switch module can be set to be large, and the purpose of reducing the quiescent current and power consumption of the Hall circuit can be achieved; secondly, the linear Hall sensor can be used for carrying out high-precision detection on the key stroke of the magnetic axis keyboard, so that the resistance value of a Hall element of the linear Hall sensor can be set to be small, and the detection precision of the linear Hall sensor meets the requirement; moreover, seamless linkage between the press stroke of the key and the brightness of the load LED lamp can be realized by using the load driving module, so that the user experience is enhanced, and software intervention is not needed.

The invention discloses a motion intention pre-judgment method for a dynamic fuzzy trajectory, and relates to the technical field of automatic driving, and the method comprises sensor data collection, multi-source data fusion and motion intention decision-making, and specifically comprises the steps: building a physical field induction network, integrating a magnetoresistive sensor array and an acoustic resonance sensor through a composite sensor unit, and obtaining a motion intention pre-judgment result; carrying out low-delay acquisition and transmission on a physical field signal by combining spectrum modulation of a vehicle-end composite antenna; according to the invention, low-delay data acquisition is realized through a composite sensor and a collaborative acquisition network, the data processing efficiency is improved by combining a distributed database and a three-layer reasoning network, parameters are optimized by utilizing edge-cloud collaborative feedback and a hybrid algorithm, and the problems of high delay, poor adaptability and the like in the traditional technology are solved. The detection precision is improved, millisecond-level response is inquired, the pre-judgment accuracy is improved, and the automatic driving safety is remarkably enhanced.

The invention provides a field calibration method based on a wireless clamp buckle type three-phase electric energy calibration device. The field calibration method comprises the following steps: establishing a wireless communication link between a three-phase electric energy meter and a portable calibration host through a wireless synchronous trigger module; three groups of split-core type current transformers are respectively connected with a detected three-phase line in a clamping manner, a Hall effect sensor and a dual-mode sampling unit of a magnetoresistive sensor are arranged in each group of split-core type current transformers, and current signal fusion processing is realized through a Kalman filtering algorithm; synchronously acquiring the three-phase voltage signals; and generating a three-dimensional verification report comprising the time mark information, the harmonic distribution diagram and the error trend curve, wherein the three-dimensional verification report is packaged by adopting an extensible markup language format and is embedded with a digital signature. According to the invention, power-off-free online verification can be realized, the current measurement precision and the communication reliability are remarkably improved, the anti-interference capability is enhanced, the complex electric energy quality analysis requirement of a new energy access scene is met, and an efficient and reliable technical means is provided for electric energy metering verification of an electric power system.

The invention provides an implantable medical device and a positioning method of a wireless energy transmission coil thereof, and the method comprises the steps: re-exciting a magnetic field through a transmitting coil in a process that the spatial position of the transmitting coil is adjusted; acquiring an induced electrical signal at the receiving coil corresponding to the process of re-exciting the magnetic field; and extracting slope characteristics from the acquired induction electric signals, and judging whether the receiving coil is aligned with the transmitting coil or not according to the slope characteristics. Sensors (such as a magnetoresistive sensor and an electronic compass) hardware do not need to be additionally arranged, the size of the implantation end is small, trauma to a patient in the implantation process is reduced, the coil alignment state is judged by extracting slope characteristics instead of judging the coil alignment state based on signal intensity (such as an absolute value of induced voltage), and the accuracy of the coil alignment state is improved. The judgment method based on the slope characteristics is higher in accuracy and better in anti-interference performance.

A manufacturing method for a magneto resistive sensor includes a first magnetization step for magnetizing a first area of an antiferromagnetic layer by applying a magnetic field in a first magnetization direction and irradiating the first area with a laser beam, and a second magnetization step for magnetizing a second area of the antiferromagnetic layer, the second area not overlapping the first area, after the first magnetization step by applying a magnetic field in a second magnetization direction that differs from the first magnetization direction and irradiating the second area with the laser beam.

The application provides a full-bridge magnetoresistance sensor and an electronic device. The circuit structure of the full-bridge magnetoresistance sensor is a full-bridge circuit structure, and the long axis directions of each sensing unit on adjacent bridge arms in the full-bridge circuit structure are parallel. The sensing unit comprises a flip function layer, a dielectric layer and a magnetoresistance thin film arranged from bottom to top. The flip function layers of the sensing units on two parallel bridge arms are connected to the same current input end, and the flip function layers of the sensing units on the other two parallel bridge arms are connected to the same ground end. By applying a single current to the current input end, the current flowing through the flip function layers of the adjacent bridge arms is opposite, so that the pinning direction of the anti-ferromagnetic layer of the sensing unit in which the heat generated by the flip function layer and the local magnetic field are reversed is opposite, and then the magnetization direction of the reference layer in the sensing unit on the adjacent bridge arm is opposite, so that a complete full-bridge structure is realized on a single chip, and the effect of flexibly setting or resetting the reference layer direction after production or during use can be achieved.

The invention relates to the technical field of steel wire rope defect detection, and discloses a high-precision steel wire rope defect detection device and a detection method thereof.The high-precision steel wire rope defect detection device comprises a broken wire gathering detection cover, a detection ring is installed on the outer wall of the broken wire gathering detection cover, and a pressure sensor is fixedly arranged on the inner wall of the side, close to the broken wire gathering detection cover, of the detection ring; a plurality of supporting assemblies are installed on the inner wall of the side, close to the pressure sensor, of the detection ring, each supporting assembly comprises a first sliding plate, a rubber wheel body is rotationally connected into the first sliding plate, an infrared distance meter is installed on the upper surface of the first sliding plate, and a plurality of magnetoresistive sensors are fixedly arranged on the inner wall of the detection ring. According to the invention, through dual recheck of a sensor detection activation video, real-time and accurate monitoring of defects such as wire breakage and abrasion of the steel wire rope is realized, the problems of strong subjectivity, low efficiency, easy missing hidden dangers and the like existing in a traditional manual visual or offline detection means are overcome, and the effects of operation safety and maintenance scientificity of the steel wire rope are remarkably improved.

The invention discloses an internet of things positioning and detecting fresh food box, which comprises a hardware architecture and a software architecture, and is characterized in that the hardware architecture comprises a main control chip, a communication module, a sensor module and a power supply module; the main control chip adopts Lexin ESP32-C3FH4 and is used for control and data processing of the whole system; the communication module comprises a 4GCat1 module and an antenna and is used for realizing remote transmission of data and receiving of a positioning signal; the sensor module comprises a temperature and humidity sensor, a magnetoresistive sensor and a vibration sensor which are respectively used for monitoring temperature and humidity, a box opening and closing state and a vibration condition; the software architecture comprises a transmission layer, a service layer, a function module layer and a hardware driving layer; the transmission layer performs data communication by adopting MQTT and HTTP (Hyper Text Transport Protocol); according to the method, the problems of full-flow positioning blind areas, incomplete environment monitoring, large-scale application obstacles and the like in the prior art are solved, the transparency and efficiency of a supply chain are improved, and the method is suitable for a fresh food full-supply-chain link.

Magnetic field sensor (100), comprising: a first bridge circuit (121) comprising a first magnetoresistive sensor, a second magnetoresistive sensor, a third magnetoresistive sensor, and a fourth magnetoresistive sensor connected as a Wheatstone bridge to detect a magnetic field along a first direction orthogonal to a plane of the first, second, third, and fourth magnetoresistive sensors; wherein The first magnetoresistive sensor includes: a first detection element (122); and a first flux guide (132; 136) comprising a first high permeability magnetic material, the first flux guide (132; 136) being disposed (i) adjacent to and (ii) above or below the first sensing element (122); the second magnetoresistive sensor includes: a second detection element (123); and a second flux guide (133; 137) comprising a second high permeability magnetic material, the second flux guide (133; 137) being disposed (i) adjacent to and (ii) above or below the second sensing element (123); the third magnetoresistive sensor includes: a third sensing element (124); and a third flux guide (134; 138) comprising a third high-permeability magnetic material, the third flux guide (138; 143) being disposed (i) adjacent to and (ii) above or below the third sensing element (124); and the fourth magnetoresistive sensor includes: a fourth detection element (125); and a fourth flux guide (135; 139) comprising a fourth high permeability magnetic material, the fourth flux guide (135; 139) being disposed (i) adjacent to and (ii) above or below the fourth sensing element (125); wherein the first (132; 136), the second (133; 137), the third (134; 138) and the fourth (135; 139) flux guides are arranged asymmetrically, so that two of the first flux guide (132; 136), the second flux guide (133; 137), the third flux guide (134; 138) and the fourth flux guide (135; 139) are arranged directly above a first edge of the respective detection element (121; 122; 123; 124) and two others of the first flux guide (132; 136), the second flux guide (133; 137), the third flux guide (134; 138) and the fourth flux guide (135; 139) are arranged directly below a second edge of the respective detection element (121; 122; 123; 124), wherein the first and second edges are arranged on opposite sides of the respective detection elements (121; 122; 123; 124).

Disclosed in the embodiments of the present invention is a magnetic tunnel junction signal isolator with electric shielding layer. In the isolator, a coil is located between a magnetic shielding layer and an electric shielding layer; the electric shielding layer is located between the coil and a magnetoresistive sensor, the magnetoresistive sensor is composed of a plurality of magnetic tunnel junctions that are connected in a series-parallel way. The two ends of the coil are electrically connected to a circuit having a first reference ground used to send a signal; a signal is sent from the magnetoresistive sensor to a receiving circuit connected to a second reference ground. The magnetic shielding layer is electrically connected to the first reference ground in a single-point or multi-point mode, or it is completely electrically isolated from the first reference ground. The electric shielding layer may instead be electrically connected to the second reference ground in a single-point or multi-point mode, or it may be completely electrically isolated from the second reference ground. Or, the electric shielding layer and magnetic shielding layer are respectively electrically connected to any potential or potentials between the first reference ground and the second reference ground in a single-point or multi-point mode. The embodiments of the present invention, prevent the electric field from corrupting the magnetoresistive sensor signal, as such solving the problem of interference and damage caused to a magnetic tunnel junction in the magnetoresistive sensor by the coil.

Techniques described herein involve an electronics-free downhole flow sensor. For example, a system can include a receiver positioned at a surface of a wellbore. A flow sensor can be positioned downhole in the wellbore. The flow sensor can include a wire positioned within a flow path of downhole fluid in the wellbore. The wire can oscillate based on flow of the downhole fluid. The flow sensor can also include a variable reluctance sensor that can detect an electrical signal that is generated by oscillation of the wire. The variable reluctance sensor can transmit the electrical signal to the receiver. The receiver may determine a resonant frequency based on the electrical signal and may determine a fluid velocity of the downhole fluid based on the resonant frequency.

The present invention provides a TMR switch for a household refrigerator. The household refrigerator includes a refrigerator body, a door, and a drive assembly for driving the door to rotate and close the refrigerator body. The door body is hinged to the refrigerator body via a door hinge. The TMR switch is fixedly installed in the lining of the refrigerator body near the door body. A magnet corresponding to the TMR switch is fixedly installed on the door body. The TMR switch includes a tunnel magnetoresistive sensor, a timer, and a trigger. The output end of the tunnel magnetoresistive sensor is electrically connected to the input end of the timer, the output end of the timer is electrically connected to the input end of the trigger, and the output end of the trigger is electrically connected to the drive assembly. The present invention can detect the open and closed state of the door body in real time and drive the door body to rotate to close the refrigerator body when the door body is open for more than a preset time. This solves the problem that refrigerators currently on the market cannot automatically close when the door body is opened to a large angle.

A method of measuring a rotational position of an assembly having circumferential ferromagnetic teeth includes applying (1302) a periodic excitation signal to an actuator, the periodicity causing a first rotational displacement of a first ferromagnetic tooth from a first rotational position to a second rotational position and a second rotational displacement of a second ferromagnetic tooth from the second rotational position to a third rotational position. The method also includes measuring (1303) a plurality of first signal outputs from a magnetoresistive sensor during the periodicity; determining one or more signal offset values based on the plurality of first signal outputs; applying the excitation signal to the actuator for a portion of a second periodicity; measuring a second signal output from the magnetoresistive sensor; generating (1304) a corrected signal by modifying the second signal output with the signal offset values; and determining (1305) the rotational position of the assembly based on the corrected signal.

This invention discloses a gyro-accelerometer output system based on a photoelectric encoder. This system converts the photoelectric encoder's photoelectric signal into pulses with positive and negative polarity during the gyro-accelerometer's precession, counting these pulses to obtain the measured apparent acceleration. This system provides an in-situ replacement for the existing variable reluctance sensor output system. This invention provides a new technical solution for obtaining apparent acceleration, transcending the output accuracy limitations of existing variable reluctance sensors, improving the accuracy of pendulum gyro-accelerometers, and offering strong resistance to electromagnetic interference.

This application provides a full-bridge magnetoresistive sensor and electronic device. The circuit structure of the full-bridge magnetoresistive sensor is a full-bridge circuit structure, in which the long axis directions of the sensing units on adjacent bridge arms are parallel. The sensing unit includes: a flip-flop functional layer, a dielectric layer, and a magnetoresistive thin film arranged from bottom to top; the flip-flop functional layers of the sensing units on two parallel bridge arms are connected to the same current input terminal, and the flip-flop functional layers of the sensing units on the other two parallel bridge arms are connected to the same ground terminal; by applying a single current to the current input terminal, the current flowing through the flip-flop functional layers of adjacent bridge arms flows in opposite directions, so that the heat generated by the flip-flop functional layer and the pinning direction of the antiferromagnetic layer in the sensing unit with local magnetic field reversal are opposite, thereby making the magnetization direction of the reference layer in the sensing unit of adjacent bridge arms opposite, thus realizing a complete full-bridge structure on a single chip, and achieving the effect of flexibly setting or resetting the direction of the reference layer after manufacturing or during use.

A contactless current sensing system and method for high power density power electronics systems are provided. The contactless current sensing system is a two current sensor system in which two current sensors having substantially the same sensitivity are positioned on opposite sides of a current-carrying conductor.