82 results about "Low frequency magnetic field" patented technology

According to the displacement modulation and optical assistance-based SERF atom magnetometer magnetic imaging method, an SERF atom magnetometer integrated with a magnetic flux guider is used as a magnetic sensor, and low-frequency magnetic field modulation is introduced to the magnetic sensor by controlling a to-be-tested sample to perform periodic infinitesimal displacement in the sensitive direction of the magnetic sensor; the modulation signal is demodulated by combining a phase-locked amplification technology, and a magnetic response signal subjected to phase-locked demodulation at each spatial position is extracted; constructing a magnetic response matrix through two-dimensional track scanning of micron-order step pitch; an image acquisition module and a reflection optical assembly are introduced for spatial registration so as to monitor the relative position in real time, and the visibility and controllability of the magnetic imaging process are guaranteed; the point-by-point detection of fT-level weak magnetic signals can be realized on the premise that an array structure is not needed; the low-frequency noise interference can be effectively inhibited, the stability and definition of direct-current and low-frequency magnetic field imaging are improved, and the method is suitable for high-resolution space imaging application of weak magnetic sources such as magnetic domain structures, nervous tissue slices and ancient rock samples.

According to the cable multi-parameter fusion sensor and method, in the cable multi-parameter fusion sensor, a shielding shell is of an open-close type metal annular structure; the zero-flux sensor module is arranged on the inner layer of the shielding shell so as to detect a cable sheath ring current signal; the pulse current sensor module is arranged on the outer side of the zero-flux sensor module so as to detect a cable partial discharge pulse current signal and an overvoltage impact current signal; the magnetic shielding layer is arranged between the zero-flux sensor module and the pulse current sensor module to shield low-frequency magnetic field interference; the zero magnetic flux sensor module and the pulse current sensor module share the shielding shell to form an electromagnetic shielding structure.

Inductor component (100) in SMD package for low-frequency magnetic fields, comprising a housing (102) with a housing base (104) for mounting on a printed circuit board, three windings arranged within the housing (102), in particular essentially orthogonal to each other, along an X, Y and Z winding axis, a plurality of connection contacts (110) arranged on the housing base (104), and a pin configuration with at least two electrical interconnections (130, 132) permanently manufactured within the housing (102), wherein each of the electrical interconnections (130, 132) electrically connects two specific terminal contacts (110) and the terminal contacts (110) are assigned to the winding ends of the X, Y and Z windings, so that each winding can be electrically connected via the terminal contacts (110).

The invention discloses an optical coupler isolation-based inertial measurement device temperature control noise suppression method, which is characterized in that electrical isolation is added between a temperature control module and a power amplification circuit, and electromagnetic noise reflection of a power element is suppressed, so that low-frequency magnetic field noise in an SERF inertial measurement device alkali metal air chamber temperature control process is suppressed. Comprising the steps that a high-frequency heating signal isolation circuit is arranged in a temperature control system of the inertial measurement device, the high-frequency heating signal isolation circuit is an optocoupler isolation circuit, and an optocoupler input side containing a light-emitting diode in the optocoupler isolation circuit is connected with an input signal from a temperature control circuit through an input signal modulation circuit; the optocoupler output side, comprising a photodiode, in the optocoupler isolation circuit transmits an output signal to a power amplification circuit which drives a heating film through a high-frequency heating signal through an output signal demodulation circuit, and the optocoupler output side and the output signal demodulation circuit are both connected with a second power supply. The optocoupler input side and the input signal modulation circuit are connected with a first power supply.

A method of data transmission includes transmitting a magnetic signal that is modulated with the bit stream, the magnetic signal having a nominal frequency and being formed of a high frequency and a low frequency, the nominal frequency being the average frequency of the magnetic signal. The bit stream is modulated onto the magnetic signal by encoding the bit stream into the magnetic signal, where each bit in the bit stream is represented by a transition between adjoining data symbols formed of K repetitions of a first state or a second state. The first state of the pair of states includes M / 2 cycles of the nominal frequency with a signal at the high frequency and M / 2 cycles of the nominal frequency with a signal at the low frequency. The second state is complementary to the first state.

A fully integrated micro search coil magnetometer (μSCM) with a low-noise instrumentation amplifier is provided for low-frequency magnetic field measurements in the range of 1Hz to 1kHz. A micro search coil formed by stacking planar spiral inductors and serially connecting them with an in-phase configuration is used for magnetic field measurements. The critical line width and inner diameter of a planar spiral inductor are theoretically calculated and experimentally verified, enabling the development of a unique CMOS layout. This layout incorporates the calculated critical inner diameter, significantly optimizing the area utilization on the CMOS die. Additionally, the CMOS die includes a polysilicon-layer inductor for on-chip calibration, a Hall effect sensor for DC magnetic field measurement, and a temperature sensor for enhanced functionality. The μSCM delivers a compact, energy-efficient, and highly sensitive solution for low-frequency magnetic field measurements, surpassing the performance of most commercially available Hall effect sensors.

The invention discloses a multi-frequency point calibration test method and system for 0-10 Hz ultralow frequency magnetic field immunity. The method comprises the steps of system building, single frequency point reference calibration, test execution and exception handling. When the system is built, the hardware modules are connected according to a specific mode; in the calibration stage, references are established for frequency points of 2Hz, 4Hz, 6Hz and 8Hz; during testing, precise field intensity control and data recording are realized through combination of coarse adjustment and fine adjustment; and verifying the probe position when abnormity occurs. The system comprises an arbitrary function generator, a power amplifier, a radiation ring and a gauss meter, and parameters of each module are adaptive to a frequency band of 0-10Hz. The field intensity larger than or equal to 1000 A / m can be stably generated, the testing precision is improved, the 0-10 Hz frequency band standard testing blank is filled, and the device is suitable for electronic equipment testing in the fields of industrial automation, new energy automobiles and the like.

The utility model provides a human body model-based low-frequency magnetic field test system, which comprises a human body model, a plurality of organ models and a data acquisition instrument are arranged in the human body model, each organ model is provided with a plurality of magnetic field probes, and the data acquisition instrument is arranged below the organ models and connected with the magnetic field probes. The human body model is filled with an electrolyte solution, and the organ model and the data acquisition instrument are both placed in the electrolyte solution. The magnetic field probe solves the problems that in the prior art, a used magnetic field probe with a fixed shape and a fixed size is greatly different from an actual human organ, and the magnetic field environment neglects the influence of human skin and in-vivo tissue fluid, so that measured magnetic field data is inaccurate.

Mobile response device (MRD) and methods and systems of using the same. Sets of MRDs are configured and deployed in a given facility, mounted to moving objects such as robots or autonomous vehicles, and / or worn by personnel. The MRD is compact and relatively low in cost to manufacture, incentivizing its wider use for increased overall safety at facilities, such as fulfillment facilities or warehouses configured with very narrow aisles (VNA) and open pedestrian zones shared with vehicles. The MRD is equipped with two tuned circuits to detect low frequency magnetic field pulses along perpendicular horizontal axes and a radio transmitter that transmits radio frequency signals when a low frequency magnetic field pulse has been detected, notifying the vehicle that generated the low frequency magnetic field pulse of the nearby presence of the MRD such that anti-collision measures can be initiated.

Tumor glycocalyx may be regarded as a glycan “canopy” above the tumor plasma membrane. Disclosed are methods of treating a neoplastic malignant cell cancer wherein the neoplastic malignant cancer cell has a malignant glycocalyx B. Also disclosed are methods of inducing apoptosis of one or more neoplastic malignant cells and methods of increasing a subject's responsiveness to an immunotherapy wherein the neoplastic malignant cancer cell has a malignant glycocalyx B.

A method of data transmission includes transmitting a magnetic signal that is modulated with the bit stream, the magnetic signal having a nominal frequency and being formed of a high frequency and a low frequency, the nominal frequency being the average frequency of the magnetic signal. The bit stream is modulated onto the magnetic signal by encoding the bit stream into the magnetic signal, where each bit in the bit stream is represented by a transition between adjoining data symbols formed of K repetitions of of a first state or a second state. The first state of the pair of states includes M / 2 cycles of the nominal frequency with a signal at the high frequency and M / 2 cycles of the nominal frequency with a signal at the low frequency. The second state is complementary to the first state.

This suppresses the decrease in current measurement accuracy caused by the skin effect. [Solution] The current sensor comprises a shield having an opening for taking in a magnetic field generated by a current flowing through a conductor, a magnetic field sensor disposed inside the shield and outputting a sensor voltage corresponding to the magnetic field at that location, and a detection circuit disposed outside the shield and detecting a current based on the sensor voltage of the magnetic field sensor, wherein the magnetic field sensor includes a first magnetic field sensor for detecting low-frequency magnetic fields and a second magnetic field sensor for detecting high-frequency magnetic fields, the first magnetic field sensor being disposed closer to the opening than the second magnetic field sensor, and the second magnetic field sensor being disposed further from the opening than the first magnetic field sensor.

The present application relates to a kind of low-frequency magnetic field generator for rat electromagnetic experiment and its uniform area measuring method, the method includes the following steps: S1, analysis display terminal calculates the magnetic induction intensity distribution of Helmholtz coil under given condition, and according to the change of magnetic induction intensity relative error determines the uniform area of magnetic field distribution, is recorded as reference area, corresponding boundary is reference boundary;S2, using magnetic field probe coil measures the magnetic induction intensity on reference boundary;S3, least square method is applied to obtain the measured boundary of magnetic field distribution uniform area;S4, according to the average absolute percentage error of magnetic induction intensity at measured boundary and reference boundary determines its actual uniform boundary;S5, analysis display terminal displays the actual uniform area of Helmholtz coil magnetic field distribution under given current amplitude and frequency, for rat electromagnetic experiment.Compared with prior art, the present application has the advantages of obtaining accurate magnetic field uniform area, reducing test workload and the like.

A system and method for applying a low strength, low frequency magnetic field therapy to biological tissues. A coil is excited with a low frequency oscillating current, e.g., 10-1000 Hz. The coil is, e.g., 5-200 turns, having a diameter of 2-20 mm, and produces a magnetic field strength of about 0.01-5 mTelsa at a distance of 1 cm from the coil, or a cover over the coil, into the tissue. The current is preferably controlled by a smartphone or other programmable device controlled by a downloadable app in accordance with a PEMF program which may be separately downloaded or updated, and provided through an audio jack. Alternately, a digital interface and / or wireless interface may control the current. An app on the smartphone may be used to control the frequency, amplitude / envelope modulation, waveform, duration, etc. of the oscillation. The coil may be in mineral housing with a simple filter, and TRRS-type audio jack.

The utility model discloses a protection mechanism for a low frequency magnetic field receiving device, which relates to the field of electronic engineering and comprises a low frequency magnetic field receiver and a shell arranged on the outer side of the low frequency magnetic field receiver, a clamping assembly is fixedly connected in the shell and comprises two electric push rods slidably connected to the inner side wall of the shell, and the two electric push rods are arranged on the inner side wall of the shell. One end of the electric push rod is fixedly connected with a connecting plate, one side of the connecting plate is fixedly connected with a telescopic rod, the outer side of the telescopic rod is fixedly sleeved with a spring, one end of the spring is fixedly connected with a protection plate, the protection plate abuts against the low-frequency magnetic field receiver, and the protection plate is fixedly connected with a trigger button. The connecting plate abuts against the trigger button in a matched mode, and the trigger button is electrically connected with the electric push rod. According to the low-frequency magnetic field receiver clamping device, the trigger button and the connecting plate are matched and abut against each other through the thrust of the electric push rod, so that the low-frequency magnetic field receiver is stably clamped, and meanwhile the clamping force can be prevented from being too large.

This application discloses a personnel rescue method based on low-frequency magnetic field communication, comprising: real-time acquisition of vital sign information of the person to be rescued to construct personnel status information; encoding the personnel status information to generate personnel status data; real-time modulation of a low-frequency magnetic field signal using the personnel status data to generate a corresponding real-time personnel status signal and radiating it outward; real-time reception of the personnel status signal using multiple magnetic field receiving units not on a straight line; and determination of the location, identity information, and vital status of the person to be rescued based on the personnel status signal. This application utilizes the physical characteristic of low-frequency magnetic field signals having minimal attenuation when penetrating obstacles such as rock layers and soil, combined with improved pulse coding technology, to achieve simultaneous detection of vital sign data, location, and identity information of trapped personnel, providing accurate and powerful reference information for optimizing rescue plans and significantly improving the efficiency of personnel rescue.

Example positioning system based on a low frequency magnetic field and apparatus are described. One example positioning system includes a low frequency magnetic field transmit apparatus and a low frequency magnetic field receive apparatus. The transmit apparatus includes a transmit coil, a conflict detect coil, and a magnetic field generation detection control module. The receive apparatus includes a receive coil and a magnetic field detection control module. When the conflict detect coil does not sense a low frequency magnetic field signal, the magnetic field generation detection control module controls the transmit coil to transmit a first low frequency magnetic field signal. When the received low frequency magnetic field signal is the first low frequency magnetic field signal, the magnetic field detection control module determines relative positions of the transmit coil and the receive coil based on signal strength of the first low frequency magnetic field signal.

The invention relates to the technical field of tracking and positioning, and provides a position detection method, device and system and a storage medium. The method is used for detecting the position of a to-be-detected object, and the to-be-detected object is provided with a receiver. The method comprises the following steps: controlling at least two magnets in an emitter matched with the receiver to rotate to generate a low-frequency magnetic field; receiving a magnetic field change induction electric signal obtained by a coil in a receiver in the low-frequency magnetic field; and determining the position of the to-be-detected object based on the magnetic field change induction electric signal. According to the scheme, position detection is achieved through the magnetic field change induction electric signal generated by the low-frequency magnetic field in the coil, interference of a metal conductor on the position detection device can be reduced, the size of the coil can be flexibly customized, the application scene of the position detection method is expanded, and the detection precision is improved.

This invention discloses a mobile terminal-based contactless anti-theft method and device based on the frequency domain characteristics of low-frequency magnetic fields. The method involves activating a magnetic field transmitting module to emit a set low-frequency magnetic field. Based on this magnetic field, a dual-mode sensing receiver collects raw three-axis magnetic field data. After high-pass filtering to remove the DC component of the Earth's magnetic field, three-dimensional AC magnetic field data is obtained. The Euclidean norm of the three-dimensional AC magnetic field data is calculated, converting it into a one-dimensional scalar signal. Based on this one-dimensional scalar signal, the Gosser algorithm is used to extract the magnetic field energy value corresponding to the target frequency in the magnetic field. The data is then demodulated and the area identification code is verified to obtain the verification result. Combining the magnetic field energy value and the verification result, a hysteresis comparison and multi-level decision logic are used to determine the security status of the protected object. When the alarm triggering conditions are met, the corresponding alarm operation is executed. This invention solves the problems of poor physical connection experience, susceptibility to false alarms due to wireless radio frequency obstruction, and high hardware tag costs in existing technologies.

Inductor component (100) in SMD package for low-frequency magnetic fields, comprising a housing (102) with a housing base (104) for mounting on a printed circuit board, three windings arranged within the housing (102), in particular essentially orthogonal to each other, along an X, Y and Z winding axis, and Connection contacts (110) arranged on the base surface (104) in a pad layout (108), wherein the dimensions of the housing base (104) and the dimensions of the connection contacts (110) provide a flat design profile with a predetermined coplanarity of the connection contacts (110), preferably with a coplanarity of at most 0.10 mm for an AOI-optimized design and at most 0.15 mm for a standard design.

The application provides a train low-frequency magnetic field interference detection method and device, the method comprises the following steps: acquiring the magnetic field intensity of the area where the train is located and the induced voltage generated by the first coil in the area when rotating; matching the corresponding relationship curve of the magnetic field intensity of the area and the induced voltage of the first coil from the relationship curve of the magnetic field intensity and the induced voltage; wherein the relationship curve is the relationship curve under different frequencies in the preset low-frequency frequency band; determining whether the train is interfered by the low-frequency magnetic field according to whether the relationship curve is matched or not. The application improves the accuracy of train low-frequency magnetic field interference detection, reduces the detection cost and is simple to operate.

The application discloses a device and method for monitoring blockage of filling pipeline based on low-frequency magnetic field, which comprises a pipeline to be monitored, a low-frequency magnetic field control circuit, a low-frequency magnetic field generating device, a monitoring mechanism and a feedback control module. The filling pipeline at the long-distance straight transportation is placed in the uniform magnetic field, and whether the pipeline is blocked is judged by monitoring the numerical change of the uniform magnetic field. Since the raw material for forming the filling slurry contains magnetic substances, the filling slurry is prone to segregation and precipitation at the long-distance transportation filling pipeline under the influence of gravity. At this time, the slurry concentration at the bottom of the pipeline gradually increases, the content of magnetic substances gradually increases, and the uniform magnetic field intensity around the pipeline is affected. Therefore, the filling pipeline is monitored according to the size of the magnetic field intensity. The device can realize non-contact monitoring of the filling pipeline, can accurately monitor the blockage of the filling pipeline and rapidly process it, is convenient and fast to install, and improves the service life of the filling pipeline and the operation efficiency of the filling operation.

An example method of estimating an arc duration in a circuit breaker includes receiving a first measurement corresponding to a low-frequency electric field emitted from a vacuum circuit breaker during an interruption or circuit break operation and a second measurement corresponding to a low-frequency magnetic field, vibration, or acoustic emitted by the vacuum circuit breaker during operation, aligning the first measurement and the second measurement in time, wherein the first measurement is calibrated according to a first physical constant and wherein the second measurement is calibrated according to a second physical constant; and determining, by a sensor-fusion algorithm or a trained AI model, an estimated duration value of an arc duration using the time-aligned first measurement and second measurement, wherein the arc duration corresponds to a first time corresponding to a separation of contacts of the vacuum circuit breaker and a second time corresponding to arc extinction.

The application discloses an underground intelligent navigation system and positioning method based on multi-sensor fusion and belongs to the technical field of mine navigation. The underground intelligent navigation system based on multi-sensor fusion is characterized by comprising a positioning base station network module, a mobile reflection terminal, a central control processing module and a monitoring center. The application solves the problems of low positioning accuracy and poor environmental adaptability of the prior art in a mine. The application combines the advantages of high-frequency pulse signals and low-frequency magnetic field signals, monitors and corrects the temperature, humidity and air pressure in the mine by using an environmental sensing unit, realizes accurate tracking of the positions of mine cars and miners in a complex environment, and further enhances the practicability and reliability by designing an efficient power consumption management mechanism and an emergency mode.

The invention provides a multi-layer directional quantum stable-phase cavity structure which comprises an inner-layer quantum cavity, a middle-layer structure shell and an outer-layer shielding shell. The inner layer quantum cavity is used for placing a quantum chip or a quantum device; the middle-layer structure shell is coaxially arranged outside the inner-layer quantum cavity in a sleeving manner; the outer layer shielding shell is coaxially arranged outside the middle layer structure shell in a sleeving manner; six-directional structural ribs are arranged on the middle-layer structural shell, so that adjustable and controllable distribution of rigidity in all directions is realized, structural modes of sensitive frequency bands of the quantum device can be effectively dispersed and avoided, and a noise guide channel network can guide incoming mechanical vibration energy to a preset dissipation path, so that the energy dissipation efficiency is improved. And the outer shielding shell adopts a composite shielding layer design, so that high-frequency electromagnetic interference and low-frequency magnetic field noise can be suppressed at the same time, thermal isolation and vibration buffering are realized in combination with an interlayer spacing structure, and a mechanical, electromagnetic and thermal triple noise suppression system is formed.

The invention discloses a composite shimming and four-group reverse proportional gradient external compensation coil system and method for simultaneous measurement of heart and brain. The method comprises the following steps: a shimming coil subsystem forms an axial cuboid uniform region in a manner that a multi-coil composite configuration is matched with non-uniform current excitation; each gradient field coil of the gradient coil subsystem is divided into four segments along the axial direction, inner and outer windings are reversely electrified, and a gradient linear region is expanded according to a non-linear proportion of current; the measurement control unit obtains magnetic field information in real time and drives the two subsystems to output a compensation magnetic field. According to the method, standardized types are classified according to site sizes, magnetic field fluctuation and gradient are taken as threshold values, shimming and gradient coil parameters are optimized, and coil constants are determined through simulation verification. According to the invention, large-scale cuboid uniform region and high-linearity gradient compensation required by heart and brain synchronous measurement are realized, low-frequency magnetic field fluctuation and gradient interference are inhibited, and the device is simple in structure and adapts to various building environments.

A method of data transmission includes transmitting a magnetic signal that is modulated with the bit stream, the magnetic signal having a nominal frequency and being formed of a high frequency and a low frequency, the nominal frequency being the average frequency of the magnetic signal. The bit stream is modulated onto the magnetic signal by encoding the bit stream into the magnetic signal, where each bit in the bit stream is represented by a transition between adjoining data symbols formed of K repetitions of of a first state or a second state. The first state of the pair of states includes M / 2 cycles of the nominal frequency with a signal at the high frequency and M / 2 cycles of the nominal frequency with a signal at the low frequency. The second state is complementary to the first state.

The invention discloses an oral targeted self-assembled nano preparation as well as a preparation method and application thereof. The preparation method comprises the following steps: enabling curcumin and first polyvinylpyrrolidone to react under the condition of a low-frequency magnetic field to prepare a first mixture; stirring 8-shogaol and second polyvinylpyrrolidone under the condition of a high-voltage electrostatic field to react, so as to prepare a second mixture; and mixing the first mixture, the second mixture and third polyvinylpyrrolidone, and carrying out a hydrogen bond self-assembly reaction to prepare the oral targeted self-assembled nano preparation. The oral targeting type self-assembly nano preparation has good water solubility, pH response release characteristic and colon cancer targeting property, is suitable for oral administration, can significantly improve the bioavailability and treatment effect of drugs, and has good clinical application prospects.

Disclosed is a combined magnetic core-type broadband current sensor. The combined magnetic core-type broadband current sensor includes a high-frequency unit surrounding a measured current for sensing the high-frequency component of the measured current, a low-frequency unit for sensing the low-frequency component of the measured current, and a transition unit that transitionally connects the high-frequency unit and the low-frequency unit. Under the excitation of the measured current, the high-frequency magnetic core generates a high-frequency magnetic field that is linearly related to the high-frequency component of the measured current. A high-frequency winding is wound on the surface of the high-frequency magnetic core to induce a high-frequency voltage signal that is linearly related to the high-frequency magnetic field. Under the excitation of the measured current, the low-frequency magnetic core generates a low-frequency magnetic field that is linearly related to the low-frequency component of the measured current. A low-frequency winding is wound on the surface of the low-frequency magnetic core to induce a low-frequency voltage signal that is linearly related to the low-frequency magnetic field. By combining the high-frequency and low-frequency magnetic cores, combined measurement of the high-frequency and low-frequency units is achieved, thereby realizing broadband measurement of pulsed current.

An electric current sensor includes a shield having an opening for capturing a magnetic field in the shield, the magnetic field having been generated by an electric current flowing through a conductor, a magnetic field sensor that is placed at a position in the shield and outputs a sensor voltage corresponding to the magnetic field at the position, and a detection circuit that is placed outside the shield and detects the electric current on the basis of the sensor voltage from the magnetic field sensor. The magnetic field sensor includes a first magnetic field sensor to detect low-frequency magnetic fields, and a second magnetic field sensor to detect high-frequency magnetic fields. The first magnetic field sensor is placed nearer to the opening than the second magnetic field sensor and the second magnetic field sensor is placed farther from the opening than the first magnetic field sensor.