302results about "Magnetic measurement environmental aspects" patented technology

Circuit and method for biasing a plate-shaped sensor element (2) made of doped semiconductor material and having a first resp. second excitation contact (C, A) connected to a first resp. second excitation node (Cn, An), and a first resp. second sense contact (B, D) connected to a first resp. second sense node (Bn, Dn). The plate-shaped sensor element is electrically isolated from a substrate or well (5) by means of a first PN-junction. The method comprises: a) applying to the first excitation node (Cn) a predefined first current (Iex) generated by a first current source (11); b) applying to the second excitation node (An) a second current (I′ex) generated by a controllable second source (12); c) controlling the second source (12) by means of a negative feedback loop based on a comparison between a value representative for a common mode voltage (Vcm) of the voltages (VB, VD) of the sense nodes (Bn, Dn) and a predefined reference voltage (Vref), such that the common mode voltage (Vcm) is substantially equal to the reference voltage (Vref).

A magnetic field measurement system, non-transitory computer-readable medium or method can include instructions for, or performance of, actions including receiving output of multiple first magnetic field sensors and multiple second magnetic field sensors; and demixing, using the output of the first and second magnetic field sensors, at least one signal from at least one target source from signals from other magnetic field sources. The demixing may be performed using a model in which the output of the first magnetic field sensors includes the at least one signal from the at least one target source and that the output of the second magnetic field sensors does not include the at least one signal from the at least one target source.

A magnetic field sensor has a circular vertical Hall (CVH) sensing element with a plurality of vertical Hall elements disposed over a common implant region in a substrate. The plurality of vertical Hall elements is disposed in an x-y plane. The magnetic field sensor is responsive to a magnetic field generated by a multi-pole magnet having a plurality of north poles and also a plurality of south poles arranged in a plane parallel to the x-y plane, and, in some embodiments, arranged in the x-y plane. A corresponding method is also described.

The present invention is directed to a system and method for assessing interference to a signal caused by magnetic field. The system includes a magnetic field generator configured to generate a magnetic field. The system further includes a first magnetic field sensor configured to detect a magnetic field and to generate a first signal representative of the magnetic field detected thereby. The system still further includes a second magnetic field sensor. The second magnetic field sensor is configured to detect a magnetic field and to generate a second signal representative of the magnetic field detected by the second magnetic field sensor. The system yet still further includes a processor. The processor is configured to receive and process the second signal to determine whether said magnetic field detected by said second magnetic field sensor may cause distortion to said first signal, as well as the magnitude of such distortion.

A method for providing offset compensation in a Hall sensor comprising at least one Hall element having a plate-shaped sensor element made of a doped semiconductor material, comprises using measurements on the Hall element itself. The method comprises obtaining a first readout signal (VH) from the at least one Hall element which is substantially dependent on the magnetic field, obtaining a second readout signal (VP) from the at least one Hall element which is substantially independent of the magnetic field, and using the second readout signal (VP) for obtaining a prediction ({circumflex over (V)}O) of the offset (VO) on the first readout signal (VH).

A system, method and computer-readable medium for mapping magnetic activity for a current linking a planet's space environment to an ionosphere of the planet are disclosed. Magnetic field measurements of the current are obtained from a plurality of satellites orbiting the planet. A residual magnetic field is determined from the obtained magnetic field measurements. The determined residual magnetic field is arranged to create a time series for a selected location of a planet-centered coordinate system. The magnetic activity is mapped using the created time series for the selected location.

An integrated semiconductor device for measuring a magnetic field, comprising: a Hall sensor, a first lateral isotropic sensor having a first stress sensitivity and a first temperature sensitivity, a second lateral isotropic sensor having a second stress sensitivity and a second temperature sensitivity, optional amplifying means, digitization means; and calculation means configured for calculating a stress and temperature compensated Hall value in the digital domain, based on a predefined formula which can be expressed as an n-th order polynomial in only two parameters. These parameters may be obtained directly from the sensor elements, or they may be calculated from a set of two simultaneous equations. A method of obtaining a Hall voltage signal, and compensating said signal for stress and temperature drift.

A magnetoresistive angular sensor and sensing method, in which an external magnetic field generator is used to provide a first mode in which a dc external magnetic field is provided in a predetermined direction and which dominates over the magnetic field generated by the input device being sensed. In a second mode, the external magnetic field is smaller. The angular sensor arrangement outputs from the two modes are combined, and this enables the input device angular orientation to be determined with offset voltage compensation.

The invention relates to a temperature and stress effect measuring device for vector magnetic properties of an electrical steel sheet. The measuring device comprises an excitation magnetic circuit module, a temperature loading module, a stress loading module, a signal detection module and support modules. The excitation magnetic circuit module employs dual U-shaped magnet yokes and is arranged between the support modules. A tested sample piece having a cross-shaped is inserted into the two magnet yokes. The temperature loading module selecting a ceramic heating piece is installed in a small groove of a lower carrying plate and is in contact with a tested electrical steel sheet. The stress loading module employs an electric push rod device to stretch or compress the sample piece. The signal detection module carries out B signal measurement by using a probe method and carries out H signal measurement by using a dual-H wire coil method. The support modules are formed by a main structural support module and a stress loading structure support module. With the measuring device provided by the invention, measurement of a vector magnetic property of an electrical steel sheet is realized under a coupling effect of the temperature and the stress for the first time; and the dimension of measurement data of magnetic characteristic of the electrical steel sheet is extended.

A detection system (100, 150) for qualitative or quantitative detection of a magnetic field property of a modulated magnetic field is described. The modulated magnetic field may e.g. stem from an adjacent electrical current (Iadj) or magnetic particles. The detection system (100, 150) comprises at least one magneto resistive sensor element (102), a current controller (104) for providing a sensing current (Isense) flowing through the magnetic sensor element (102) and a controlling means (108). The controlling means (108) is adapted for deriving at a first frequency f1 a temperature-related parameter of the at least one magneto resistive sensor. The controlling means (108) furthermore is adapted for deriving a qualitative or quantitative characteristic of the adjacent electrical current (Iadj) or magnetic particles, taking into account the derived temperature-related parameter. This second frequency (f1) is different from the first frequency (f1)). The invention also relates to a corresponding method.

The invention discloses a single-beam atom magnetometer bias and noise suppression device and method based on light intensity difference, wherein the method comprises the steps: light generated by a laser is shaped by a first cylindrical lens and a second cylindrical lens in sequence and then is split after passing through a lambda / 2 wave plate and a polarization light splitting prism, one beam passes through an optical filter to make light intensity attenuated, and the attenuated light reaches a first photoelectric detector; the other beam sequentially enters a lambda / 4 wave plate and a diaphragm in a magnetic shielding barrel through an optical fiber coupling head after passing through a polarizer and then irradiates an atomic gas chamber, the light beam transmitted out of the gas chamber is influenced by atomic spin precession, and the polarization axis of linearly polarized light deflects; the light is outputted and reaches a second photoelectric detector; and the two beams of light are amplified by a photodiode amplifier after passing through the first photoelectric detector and the second photoelectric detector, and a lock-in amplifier is used for extracting frequency information in output signals of the amplifier. By differentiating the light intensities of the light beams in front of and behind an atom air chamber, the bias of the background light intensity in an atom non-polarized state and the light intensity noise before and after detection are eliminated, and the sensitivity of an atom magnetometer is improved.

The present invention relates to a measurement method for detecting a relative position of a magnetic field source in relation to a magnetic field sensor. At least two magnetic field components of the produced magnetic field are detected by means of the magnetic field sensor. The present invention further also relates to a corresponding displacement sensor. According to the present invention, an output signal which corresponds to the position of the magnetic field source relative to the magnetic field sensor is established, based on a quotient of the detected magnetic field components and an offset correction, wherein the effect of the temperature on the produced magnetic field is compensated for before the output signal is established.

The invention provides a superconducting tape testing device which comprises a testing station and a Duwa container wherein the testing station further includes a base; a stretching part consisting of several first screw rods that stand vertically on the base and a sliding plate cooperating with the first screw rods; a fixing part consisting of a lower clamping body arranged on the base and an upper clamping body arranged in a rotation manner on the sliding plate; and a twisting part consisting of several rotation plates arranged on the upper clamping body through several vertical rods. The rotation plates can drive the upper clamping body to rotate. The Duwa container is filled with liquid nitrogen which cools the superconducting tape to a superconducting state. The superconducting tape testing device of the present invention integrates the functions of tape fixing, stretching and twisting and is capable of performing critical current testing under stretching and twisting combined stresses, and the stretching and twisting combined stresses can be easily adjusted. Therefore, the testing device has high testing efficiency.

A method for measuring the temperature rise induced by bias current / bias voltage in a magnetic tunnel junction, the method includes the steps of: (a) applying an external time-changing magnetic field to the magnetic tunnel junction; (b) measuring different first outer pin flip field values under different temperature values; (c) calculating the correlation between the temperature and the outer pin flip field according to the temperature values and the first outer pin flip field values; (d) measuring different second outer pin flip field values under different bias current / bias voltage values; (e) calculating the correlation between the bias current / bias voltage and the outer pin flip field according to the bias current / bias voltage values and the second outer pin flip field values; (f) calculating the correlation between the temperature and the bias current / bias voltage according to the results produced by the steps (c) and (e). The method of the present invention can obtain the correlation between the temperature and the bias current / bias voltage, thereby determining what kind of TMR reader design providing more stable and reliable reading performance especially under higher operational temperature.

A field-sensor device comprises a reference field sensor biased with a reference current. The reference field sensor provides a reference sensor signal in response to a field, and a calibrated field sensor biased with an individually adjustable current and providing a calibrated sensor signal in response to the field. A control circuit controls the adjustable current bias of the calibrated field sensor at a calibrated current different from the reference current so that the calibrated field sensor provides a calibrated sensor signal substantially equal to the reference sensor signal in response to a common field. The field sensor device is arranged to be exposed, when in a calibration mode, to a uniform calibration field and, when in operational mode, to an operational field being a field gradient.

Disclosed is a Hall Effect instrument with the capability of compensating for temperature drift consistently, accurately and in real time of operation. The instrument embodies a four-point ohmmeter circuit measuring Hall Effect sensor resistance and tracking the effect of temperature on the Hall Effect sensor. The instrument takes into account a relationship between the temperature and a temperature compensation index on a per probe basis, which has exhibited a deterministic difference observed by the present inventor.

Apparatus, systems, and methods are provided for sensing devices. An exemplary sensing device includes a sensing arrangement on a substrate to sense a first property, a heating arrangement, and a control system coupled to the first sensing arrangement and the heating arrangement to activate the heating arrangement to heat the first sensing arrangement and deactivate the heating arrangement while obtaining one or more measurement values for the first property from the first sensing arrangement.

The invention discloses a Hall sensor temperature drift compensation circuit. When the working environment temperature of the Hall sensor changes, the temperature drift of the Hall sensor is compensated in real time, and the Hall voltage is increased or decreased by increasing or decreasing the bias current of the Hall device, so that the compensation of the temperature drift of the Hall sensor isrealized. Simulation results show that the temperature drift coefficient of the compensated Hall sensor within the temperature range of-40 DEG C to 120 DEG C is 45 ppm / DEG C.

The present invention discloses a magnetic field sensing device that utilizes a single coil for calibrating the response of the sensor to compensate for temperature dependent sensitivity drift and also for resetting the magnetic field sensor in order to eliminate hysteresis. The single coil configuration is advantageous since it reduces the size of the sensor chip by decreasing the number of contact pads on the chip and also because it wastes less space, which permits an increase in the density of the magnetoresistive elements on the sensor chip.

The invention provides a gradient eddy current correction method and a gradient eddy current correction device for a magnetic resonance imaging system. The method comprises the following steps: building an eddy current field model, wherein the eddy current field model uses Laplace transform to represent an eddy current field; collecting eddy current measurement data, and using the eddy current field model to process the eddy current measurement data to acquire the initial parameter values of the eddy current field model; fitting the parameter values of the eddy current field model according to the eddy current measurement data and the initial parameter values to get a calibrated eddy current field model; and correcting gradient eddy current according to the calibrated eddy current field model.

The invention discloses a weak magnetic sensor based on magneto-optical coupling and a magnetic field measurement method and relates to the technical field of magnetic performance measurement devices. The sensor comprises a base, a magnetostrictor, a double-side Faraday reflector, an optical fiber collimation probe, a single mode fiber and a Michelson interference device, wherein one end of the magnetostrictor is mechanically and fixedly connected with the base, the other end of the magnetostrictor adheres to the double-side Faraday reflector, the optical fiber collimation probe is connected with the Michelson interference device through the single mode fiber, and the center of the optical fiber collimation probe and the center of the double-side Faraday reflector are located on the same axis. The external magnetic field is sensed through the magnetostrictor so that the reflector can be driven to make linear movement, displacement-phase photovoltaic conversion and detection are achieved through the Michelson optical interference device, and then the intensity of the magnetic field is obtained. According to the sensor, the complicated design of traditional magnetoelectricity sensors is avoided, the influence of temperature is effectively reduced, sensitivity is high, repeatability is high, and high-precision low-intensity magnetic field measurement in the complicated magnetoelectricity environment can be achieved.

An electromagnetic gradiometer that includes multiple torsionally operated MEMS-based magnetic and / or electric field sensors with control electronics configured to provide magnetic and / or electric field gradient measurements. In one example a magnetic gradiometer includes a first torsionally operated MEMS magnetic sensor having a capacitive read-out configured to provide a first measurement of a received magnetic field, a second torsionally operated MEMS magnetic sensor coupled to the first torsionally operated MEMS magnetic sensor and having the capacitive read-out configured to provide a second measurement of the received magnetic field, and control electronics coupled to the first and second torsionally operated MEMS magnetic sensors and configured to determine a magnetic field gradient of the received magnetic field based the first and second measurements from the first and second torsionally operated MEMS electromagnetic sensors.

A magnetic sensor includes a magnetoresistive effect element having a sensitivity axis in a specific direction. The magnetoresistive effect element has on a substrate, a laminate structure in which a fixed magnetic layer and a free magnetic layer are laminated with a nonmagnetic material layer interposed therebetween and includes at a side of the free magnetic layer apart from the nonmagnetic material layer, a first antiferromagnetic layer which generates an exchange coupling bias with the free magnetic layer and aligns a magnetization direction thereof in a predetermined direction in a magnetization changeable state. The free magnetic layer includes a first ferromagnetic layer in contact with the first antiferromagnetic layer to be exchange-coupled therewith and a magnetic adjustment layer at a side of the first ferromagnetic layer apart from the first antiferromagnetic layer. The magnetic adjustment layer contains at least one iron group element and at least one platinum group element.

A method for detecting deterioration of a permanent magnet in an electric motor is characterized by peak current measuring steps and a determination step. In the first peak current measuring step, when the electric motor is started, a first pulsed voltage is applied to the multi-phase coils so as to generate magnetic flux directed in the same direction as generated by the permanent magnet and a first peak current is measured. In a second peak current measuring step, a second pulsed voltage is applied to the multi-phase coils so as to generate magnetic flux directed in the direction opposite to the direction in which magnetic flux is generated by the permanent magnet and a second peak current is measured. In a determination step, it is determined whether or not the permanent magnet is deteriorated based on the difference of the absolute value between the first and the second peak currents.

The invention provides a power package with an integrated magnetic field sensor. A power semiconductor package includes a substrate having a plurality of metal leads, a power semiconductor die attached to a first one of the leads and a magnetic field sensor integrated in the same power semiconductor package as the power semiconductor die and positioned in close proximity to a current pathway of the power semiconductor die. The magnetic field sensor is operable to generate a signal in response to a magnetic field produced by current flowing in the current pathway, the magnitude of the signal being proportional to the amount of current flowing in the current pathway.

A Hall sensor apparatus with a temperature measurement function and a current sensor apparatus with the same function are provided, and the temperature measurement function for measuring a temperature of a Hall sensor is implementable on the Hall sensor instead of an application specific integrated circuit (ASIC) that is a controller for driving the Hall sensor or a current sensor and the ASIC is installable far away from the Hall sensor, and thus a rise in temperature of the ASIC is preventable such that a stable measurement of the Hall sensor or the current sensor and stable driving control thereof is allowable.

The invention discloses a Hall sensor. The Hall sensor comprises a power supply module, a current driving module, differential pairs formed by N Hall sheets and a signal amplification module. The power supply module is used for supplying power to all the modules in the Hall sensor. The current driving module is used for supplying constant driving current to the Hall sheets. The Hall plates are used for generating an induced voltage signal proportional to the magnetic induction intensity when a magnetic field perpendicular to the Hall plates is induced and forming the differential pairs for eliminating the external common-mode interference. The amplification module is used for amplifying the power of the induced voltage signal outputted by the Hall plates and outputting the amplified signal. According to the technical scheme, the electromagnetic interference to the signal from the outside of the sensor in the measurement process can be effectively avoided and the measurement accuracy ofthe Hall sensor can be improved.