441results about "Magnetic field offset compensation" patented technology

The present invention provides a method to compensate for the sensitivity drift of a magnetic field sensor for sensing a magnetic field. The magnetic field sensor comprises at least four electrodes. The method comprises a first step where a first set of two electrodes is used to bias the sensor and a second set of two electrodes is used to sense an output signal of the magnetic field sensor, and a second step where the second set of two electrodes is used to bias the sensor and the first set of two electrodes is used to sense an output signal of the magnetic field sensor. The method is characterized in that at least one of the first or the second step is subdivided in at least a first sub-step and a second sub-step. A reference magnetic field has first magnetic field parameters, e.g. a first amplitude and / or direction, in the first sub-step and second magnetic field parameters, a second amplitude and / or direction, in the second sub-step. An output signal is sensed in the first and in the second step, and within the first or the second step an output signal is sensed in the first and the second sub-step.

A device is proposed for high-resolution measurement, in particular for high-resolution absolute measurement of magnetic fields, having a network (1) of transitions (3) between superconductors (5, 6) which exhibit Josephson effects, called junctions below, the network comprising closed meshes (7, 8, 9, 10, 11, 12, 13), denoted by cells below, which in each case have junctions (3), which junctions are connected in a superconducting fashion, and at least three of these cells being connected in a superconducting and / or nonsuperconducting fashion. The object of the invention consists in further developing this device in such a way that it is possible to make absolute measurements of magnetic fields in a highly sensitive fashion. This object is achieved by virtue of the fact that the junctions (3) of the at least three cells (7, 8, 9) can be energized in such a way that a time-variant voltage drops in each case across at least two junctions of a cell, the time average of which voltage does not vanish, and in that the at least three cells are configured differently geometrically in such a way that the magnetic fluxes enclosed by the cells in the case of an existing magnetic field differ from one another in such a way that the frequency spectrum of the voltage response function has no significant Phi0-periodic component with reference to the magnetic flux.

A calibratable magnetic field sensor for sensing a first and a second spatial component of a magnetic field in a reference point, wherein the magnetic field includes a first and a second measurement field component and / or a first and a second calibration field component. The magnetic filed sensor includes a first sensor element arrangement including at least a first and a second sensor element for sensing the first magnetic field component, which includes a first measurement field component and / or a first calibration field component, with respect to a first spatial axis in the reference point. Furthermore, the magnetic field sensor includes a second sensor element arrangement for sensing the second magnetic field component, which includes a second measurement field component and / or a second calibration field component, with respect to a second spatial axis in the reference point. The magnetic filed sensor also includes an excitation line arranged with respect to the first sensor element arrangement so that, when impressing a default current into the excitation line, a pair of different asymmetrical default calibration field components in the first sensor element and in the second sensor element is generated with respect to the first spatial axis in the first sensor element arrangement, wherein the two spatial axes pass along linearly independent position vectors.

The present invention provides a method to compensate for the sensitivity drift of a magnetic field sensor for sensing a magnetic field. The magnetic field sensor comprises at least four electrodes. The method comprises a first step where a first set of two electrodes is used to bias the sensor and a second set of two electrodes is used to sense an output signal of the magnetic field sensor, and a second step where the second set of two electrodes is used to bias the sensor and the first set of two electrodes is used to sense an output signal of the magnetic field sensor. The method is characterized in that at least one of the first or the second step is subdivided in at least a first sub-step and a second sub-step. A reference magnetic field has first magnetic field parameters, e.g. a first amplitude and / or direction, in the first sub-step and second magnetic field parameters, a second amplitude and / or direction, in the second sub-step. An output signal is sensed in the first and in the second step, and within the first or the second step an output signal is sensed in the first and the second sub-step.

A magnetic field sensor for detecting first, second, and third spatial components of a magnetic field at a reference point includes a first sensor element arrangement for detecting the first magnetic field component having a first measurement field component and a first calibration field component with respect to a first spatial axis at a reference point, a second sensor element arrangement for detecting the second magnetic field component having a second measurement field component and a second calibration field component with respect to a second spatial axis y at the reference point and a third sensor element arrangement for detecting the third magnetic field component having a third measurement field component and a third calibration field component with respect to a third spatial axis x at the reference point. An excitation line is arranged such with respect to the three sensor element arrangements that when impressing a predetermined current into the excitation line respective predetermined calibration field components with respect to the spatial axes in the sensor element arrangements are generated.

A magnetic field measurement system includes at least one magnetometer; and at least one flux concentrator made of a high magnetic permeability material and configured to receive magnetic field signals from a source, to concentrate the magnetic field signals or reorient the magnetic field signals in a preselected direction, and to direct the concentrated or reoriented magnetic field signals toward at least one of the at least one magnetometer. In addition to, or as an alternative to, the flux concentrator, the system can include a passive shield made of the high magnetic permeability material. The system may also include active shielding.

A magnetic field measurement system includes an array of magnetometers; at least one magnetic field generator with each of the at least one magnetic field generator configured to generate a first magnetic field at one or more of the magnetometers, wherein the generated first magnetic field combines with the ambient magnetic field to produce a directional magnetic field at the one or more of the magnetometers, where a magnitude and direction of the directional magnetic field is selectable using the at least one magnetic field generator; and a controller coupled to the magnetometers and the at least one magnetic field generator, the controller including a processor configured for receiving signals from the magnetometers, observing or measuring a magnetic field from the received signals, and controlling the at least one magnetic field generator to generate the first magnetic field and select the direction of the directional magnetic field.

A magnetic field measurement system includes an array of magnetometers; at least one magnetic field generator configured to generate a compensation field across the array of magnetometers; and a controller coupled to the magnetometers and the at least one magnetic field generator and configured for adjusting a dynamic range and sensitivity of the array by adjusting a spatial variation of the compensation field to alter which of the magnetometers of the array operate in a measurement mode. Another magnetic field measurement system utilizes at least one magnetometer instead of the array. The controller is configured for adjusting a dynamic range and sensitivity of the array by adjusting a spatial variation of the compensation field to alter which of multiple domains within the at least one magnetometer operate in the measurement mode

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 method of operating an optically pumped magnetometer (OPM) includes directing a light beam through a vapor cell of the OPM including a vapor of atoms; applying RF excitation to cause spins of the atoms to precess; measuring a frequency of the precession; for each of a plurality of different axes relative to the vapor cell, directing a light beam through the vapor cell, applying a magnetic field through the vapor cell along the axis, applying RF excitation to cause spins of the atoms to precess, and measuring a frequency of the precession in the applied magnetic field; determining magnitude and components of an ambient background magnetic field along the axes using the measured frequencies; and applying a magnetic field based on the components around the vapor cell to counteract the ambient background magnetic field to facilitate operation of the OPM in a spin exchange relaxation free (SERF) mode.

The invention provides a single chip difference free layer push-pull type magnetic field sensor electric bridge and a preparation method thereof. The magnetic field sensor electric bridge comprises a substrate, a staggered soft magnetic flux concentrator array and a GMR spin valve or a TMR magnetic resistor sensor unit array which is placed on the substrate and has an X-direction magnetic sensitive direction. Each soft magnetic flux concentrator comprises edges parallel to the X axis, edges parallel to the Y axis and four corners, and the four corners are sequentially marked as A, B, C and D from the upper left position in the clockwise direction. Magnetic resistor sensor units are placed at the gaps between the soft magnetic flux concentrators. Meanwhile, the magnetic resistor sensor units corresponding to the corners A and the corners C of the soft magnetic flux concentrators and the magnetic resistor sensor units corresponding to the corners B and the corners D are defined as push magnetic resistor sensor units and pull magnetic resistor sensor units respectively. The push magnetic resistor sensor units are electrically connected to form one or more push arms, the pull magnetic sensor units are electrically connected to form one or more pull arms, and the push arms and the pull arms are electrically connected to form a push-pull type sensor bridge. According to the single chip difference free layer push-pull type magnetic field sensor electric bridge and the preparation method therefore, the power consumption is low, the magnetic field sensitivity is high, and a magnetic field in the Y direction can be measured.

A calibratable magnetic field sensor for sensing a first and a second spatial component of a magnetic field in a reference point, wherein the magnetic field includes a first and a second measurement field component and / or a first and a second calibration field component. The magnetic filed sensor includes a first sensor element arrangement including at least a first and a second sensor element for sensing the first magnetic field component, which includes a first measurement field component and / or a first calibration field component, with respect to a first spatial axis in the reference point. Furthermore, the magnetic field sensor includes a second sensor element arrangement for sensing the second magnetic field component, which includes a second measurement field component and / or a second calibration field component, with respect to a second spatial axis in the reference point. The magnetic filed sensor also includes an excitation line arranged with respect to the first sensor element arrangement so that, when impressing a default current into the excitation line, a pair of different asymmetrical default calibration field components in the first sensor element and in the second sensor element is generated with respect to the first spatial axis in the first sensor element arrangement, wherein the two spatial axes pass along linearly independent position vectors.

Methods and apparatus for processing a signal comprise at least one circuit configured to generate a measured signal during a measured time period and a reference signal during a reference time period. Also included is at least one dual- or multi-path analog-to-digital converter comprising at least a first processing circuit configured to process the measured signal, at least a second processing circuit configured to process the reference signal, and a third processing circuit configured to process both the measured signal and the reference signal.

A reading circuit for a magnetic-field sensor, generating an electrical detection quantity as a function of a detected magnetic field and of a detection sensitivity, is provided with an amplification stage, which is coupled to the magnetic-field sensor and generates an output signal as a function of the electrical detection quantity and of an amplification gain. In particular, the amplification gain is electronically selectable, and the reading circuit is moreover provided with a calibration stage, integrated with the amplification stage and configured so as to vary a value of the amplification gain in such a way as to compensate a variation of the detection sensitivity with respect to a nominal sensitivity value.

Apparatus for detecting a passing magnetic article includes a peak detector providing a detector output signal that changes state when the magnetic field signal differs from a magnetic field tracking signal by more than a threshold offset amount. The threshold offset amount is dynamically variable in response to detection of a speed of rotation of the magnetic article and a peak-to-peak signal level of the magnetic field signal.

The invention discloses an autonomously calibrated magnetic field sensor. The magnetic field sensor including a magnetic field sensing circuit (2) comprising a reference magnetic field generator (8) and a magnetic field sensing cell (6), and a signal processing circuit (4) connected to the output of the magnetic field sensing cell and comprising a demodulator circuit and a gain correction feedback circuit (30, 28, 47) for correcting error fluctuations in the transfer characteristic of the magnetic field sensor. The sensor further comprises a reference current generator (3)configured to generate a reference current I ref, the reference current generator connected to the magnetic field sensing circuit (2) configured for generating the reference magnetic field B ref and to the gain correction feedback circuit configured for providing a reference signal (y ref ) to which an output signal of the demodulator circuit may be compared.

The invention relates to the technical field of current sensors, and provides an optical fiber current transformer based on a diamond NV color center and a measuring method. The optical fiber current transformer comprises laser excitation and reflected light receiving analysis equipment, a diamond NV color center probe, a magnetic concentrator and microwave excitation equipment, wherein the transformer adopts three measurement methods, namely an all-optical measurement method, a non-all-optical measurement method and a combined measurement method. The optical fiber current transformer is simple in structure, high in practicability, capable of resisting external interference and high in robustness, the optical fiber is only used for transmission of exciting light and collection of fluorescent light, thus bending and twisting of the optical fiber do not affect a detection result to a certain extent, and the use is more convenient; in addition, by optimizing the NV color center concentration and the spinning property in the diamond, the sensitivity of magnetic field measurement can be remarkably improved, and the possibility is provided for current measurement with higher precision.

A magnetic shielded package includes a magnetic device, a first magnetic shield member, and a second magnetic shield member. The first magnetic shield member is disposed below the magnetic device. The second magnetic shield member is disposed on the first magnetic shield member so as to cover the magnetic device. An opening portion is formed in the first magnetic shield member (i) at such a position as not to be adjacent to an outer circumference of the first magnetic shield member or (ii) an upper wall of the second magnetic shield member.

A method for measuring current in an electric network comprising at least one first electric line. The method includes fitting the first line with a circuit breaker having a protection coil and having a wall traversed by a magnetic field emitted by the protection coil; arranging on the wall of the circuit breaker a synchronous three-axis digital magnetometer on a semiconductor chip; by way of the digital magnetometer, measuring at least one component of a magnetic field emitted by the coil; and determining the value of a current traversing the electric line from the measured component.

A sensor apparatus comprises a first magnetic transducer which in use is positioned on a first side of a barrier and a second magnetic transducer which in use is positioned on a second side of the barrier opposite the first side. The second transducer comprises a magnetic or electrical property which is dependent upon a sensible condition on the second side of the barrier, such as the pressure or temperature on the second side of the barrier. In operation, the first transducer generates a first magnetic field which induces the second transducer to generate a second magnetic field that is dependent upon the magnetic or electrical property of the second transducer. The first transducer detects the second magnetic field and generates a signal which is representative of the sensible condition on the second side of the barrier.

The invention discloses a magnetic sensor device with low electric offset and high sensitivity, a method thereof, and a magnetic sensing system. The magnetic sensing system includes: a magnetic component proximate a movable mechanical component; and a magnetic sensor configured to determine a movement of the mechanical component based on a magnetic field produced by the magnetic component. The magnetic sensor includes: a low-offset magnetic sensing element; a high-sensitivity magnetic sensing element; and an offset compensation circuit configured to: determine a zero-crossing of a sensing field from an output of the low-offset magnetic sensing element; sample an offset value of the high-sensitivity magnetic sensing element at the zero-crossing; and subtract the offset value from an output of the high-sensitivity magnetic sensing element.

A calibration arrangement of a magnetic field measurement device includes at least one attachment point nub configured for attachment to the magnetic field measurement device; mounting arms extending from the at least one attachment point nub; and reference coil loops distributed among the mounting arms. A magnetic field measurement system includes the calibration arrangement and a magnetic field measurement device including a sensor mounting body, magnetic field sensors disposed on or within the sensor mounting body, and at least one primary attachment point formed in or on the sensor mounting body configured to receive the at least one attachment point nub of the calibration arrangement.

The present invention relates to a magnetic field sensing device (50) comprising several functionally different layers (38, 60, 70), wherein a Wheatstone bridge layer (70) comprises at least two resistors (20) of a Wheatstone bridge (18), each resistor (20) comprises at least one magnetic field sensing element (10) in the form of a resistor subelement (22), and a flip conductor layer (38) comprising at least one flip conductor (30) for flipping the internal magnetization state of each magnetic field sensing element (10). The flip conductor (30) comprises a plurality of conductor stripes (32) being arranged on at least two different flip conductor sublayers (38-1, 38-2) of said flip conductor layer (38) and being electrically coupled with each other through vias.The multilayer arrangement of said flip conductor (30) provides a compact design of said magnetic field sensing device (50), such that a decreased power consumption, decreased inductance and improved sensitivity of the magnetic field sensing device can be achieved.

Magnetic field sensor having a vertical Hall sensor element arranged in a semiconductor substrate, and an exciting conductor arrangement having at least one exciting conductor, the exciting conductor being arranged within an exciting conductor plane which is spaced apart, in parallel to the substrate surface, from the vertical Hall sensor element at a vertical distance h1 having a tolerance range Δh1 which is due to the manufacturing process, and which exciting conductor further has a lateral distance d1 as an offset from a center position which is located, in relation to the substrate surface, perpendicularly to the vertical Hall sensor element, and the lateral distance d1 being dimensioned such that a vertical calibration component B1x of a magnetic flux density B1 created by the exciting conductor arrangement in the vertical Hall sensor element changes by less than 5% within the tolerance range Δh1 for the vertical distance h1.

There are provided an azimuth measurement device and its method for realizing an update of an offset calculated from the data acquired by azimuth measurement. A geomagnetism output measured by a 3-axis magnetic sensor is amplified and input to an A / D conversion section. A chopper section is arranged for switching the terminals for driving an X-axis, Y-axis and a Z-axis magnetic sensor and applies drive voltage output from a drive power source section to the X-axis, the Y-axis and the Z-axis magnetic sensor. The output amplified value amplified by the amplification section is converted from an analog signal to a digital signal by the A / D conversion section and then is input to a sensitivity / offset correction calculation section. Output data from this sensitivity / offset correction calculation section is input to an azimuth calculation section and the corresponding azimuth information is output. A reliability information calculation section outputs reliability information.

A magnetic field sensor and a method include a modulator coupled in a feedback arrangement and operable to modulate a calibration feedback signal with a modulator clock signal having a selected frequency and a selected relative phase operable to remove a gain error in the magnetic field sensor and in the method.

A magnetic-field sensor includes: a chip including a substrate having a first surface and an insulating layer covering the first surface; first and second magnetoresistors each extending into the insulating layer and having a main axis of magnetization and a secondary axis of magnetization; a first magnetic-field generator configured to generate a first magnetic field having field lines along the main axis of magnetization of the first magnetoresistor; a second magnetic-field generator configured to generate a second magnetic field having field lines along the main axis of magnetization of the second magnetoresistor. The main axes of magnetization extending transversely to each other and the secondary axes of magnetization extending transversely to each other. The first and second magnetoresistors extend into the insulating layer at a first distance and a second distance, respectively, that differ from one another, from the first surface.

There are provided an azimuth measurement device and its method for realizing an update of an offset calculated from the data acquired by azimuth measurement. A geomagnetism output measured by a 3-axis magnetic sensor is amplified and input to an A / D conversion section. A chopper section is arranged for switching the terminals for driving an X-axis, Y-axis and a Z-axis magnetic sensor and applies drive voltage output from a drive power source section to the X-axis, the Y-axis and the Z-axis magnetic sensor. The output amplified value amplified by the amplification section is converted from an analog signal to a digital signal by the ND conversion section and then is input to a sensitivity / offset correction calculation section. Output data from this sensitivity / offset correction calculation section is input to an azimuth calculation section and the corresponding azimuth information is output. A reliability information calculation section outputs reliability information.

Systems, methods, and computer-readable media for efficiently testing sensor assemblies are provided. A test station may be operative to test a three-axis magnetometer sensor assembly by holding the assembly at each one of three test orientations with respect to an electromagnet axis. At each particular test orientation for each particular sensor axis, a difference may be determined between any magnetic field sensed by that sensor axis during the application of a first magnetic field along the electromagnet axis and any magnetic field sensed by that sensor axis during the application of a second magnetic field along the electromagnet axis. Those determined differences may be leveraged with the magnitudes of the first and second magnetic fields and the vector component of the electromagnet axis on each one of the sensor axes at each one of the test orientations to determine the sensitivity performances for each one of the sensor axes.