41 results about "Search coil" patented technology

An apparatus and method for determining a condition of an electric machine. Search coils are wound around stator teeth and the induced voltage is used to decouple stator and rotor fluxes. The decoupled fluxes allow for machine condition monitoring and fault diagnosis.

Provided is a contactless power transfer device for a moving object. Each of a power transmission coil and a power receiving coil comprises an H-shaped core, and first, second and third search coils are installed on a magnetic pole object of the H-shaped core of the power transmission coil. A y-direction positional deviation between the power transmission coil and the power receiving coil is detected using voltages measured at the first and second search coils, and an x-direction positional deviation is detected using voltages measured at the third search coils.

The present invention discloses a magnetic clamping device having at least one magnetic holding unit comprising a switchable magnet generating a magnetic clamping force at a workpiece and a sensing means, wherein said sensing means comprises a search coil adapted to provide a detection signal indicative of a magnetic flux being applicable for at least approximately determining a clamping force exerted on the workpiece to be clamped and a method for detecting an operating state of a magnetic clamping device.

The invention discloses a device and a method for monitoring and protecting a series reactor. A search coil assembly is arranged inside or outside a dry type air core reactor coil body; one side of the search coil assembly corresponds to the reactor; the other side of the search coil assembly is correspondingly provided with an isolation transformer; one end of the isolation transformer is grounded; the other end of the isolation transformer is connected in series with a filter module; the filter module, a resistor and a TVS (Transient Voltage Suppressor) are connected in series in sequence and then grounded; the filter module and a data acquisition module are connected in series in sequence and then grounded; and the data acquisition module is connected with a control computer. The device and the method for monitoring and protecting the series reactor have the beneficial effects that the occurrence of serious accidents such as reactor firing is prevented, and the operation safety coefficient of a current limiting reactor is improved, so that the safe operation of the transformer is guaranteed.

The invention discloses a linear induction electron accelerator test platform and a double-coil detection structure. The structure includes: a PCB board, a detection coil A, organic glass, and a detection coil B; the organic glass is fixed on the wall of the beam pipe, and the PCB board Fixed on the plexiglass, the detection coil A and the detection coil B are fixed on the PCB board, wherein the grounding direction of the detection coil A and the detection coil B is opposite; it solves the existing technical problems of complex detection structure and high industrial requirements, and realizes The invention has the advantages of simple structure, low process requirements, no influence on beam transmission, and improved beam radius diagnosis efficiency.

A portable metal detection system that includes a hand/wrist mounted metal detector with two search coils mounted on the palm side of the detector. The mounted metal detector includes a wireless transmitter and a small rechargeable fuel cell. The detection system also includes a separate housing that contains a wireless receiver, a small rechargeable fuel cell and an adjustable vibration or audio alert circuitry. The separate housing may be worn anywhere on the operator of the system. Once the hand/wrist mounted metal detector detects a metal object, the wireless transmitter sends a signal to the wireless receiver in the separate housing that activates the vibration or audio alert circuitry. The separation of the detection device and the alert circuitry prevents a metal detection detainee from hearing or feeling a metal detection alert.

A new dual field search coil for pulse induction metal detectors has multiple coplanar wire coils of different diameters connected in series with the output of a pulse source, overcoming the loss of target size resolution associated with a single coil search loop. Small objects are sensed by an internal small coil and larger objects are sensed by the larger outside coil, and the overall depth of target sensing remains similar to that of a single coil construction. The smaller coil is isolated from the pulse source by the inductance of the larger coil and will ring at a frequency determined by its own parameters. To prevent the smaller coil from ringing, a second damping resistor is connected across the terminals of the smaller coil at the junction of the large and small coils making up the modified search loop.

The invention discloses an open-type magnetic field shielding device capable of adjusting at full frequency band, and belongs to the technical field of electromagnetic compatibility. The magnetic field shielding device comprise a magnetic field searching coil, a magnetic field detection oil, a driving circuit, a magnetic field adjustment coil and a corresponding matched sample table, wherein the magnetic field detection coil is used for monitoring change of an environmental magnetic field, the magnetic field adjustment coil is driven to offset with an external magnetic field by the driving circuit after a power is amplified, the magnetic field searching coil is placed right above the device, the sample table is placed in the center of the magnetic field adjustment coil, the magnetic fielddetection coil is connected with a magnetic field detection probe and is placed on the sample table, the driving circuit is placed at an outer side of the magnetic field adjustment coil, and a shielded magnetic field is arranged above the driving circuit. The magnetic field shielding device capable of adjusting at full frequency band is more beneficial for engineering practice.

Embodiments of the present invention provide for a system and apparatus for mobile device integration of a portable metal detector. In an embodiment of the invention, a portable metal detector includes a shaft, a handle attached to shaft, a mobile device housing attached to the handle, and a search coil attached to a distal end of the shaft. The search coil includes a search coil configured to wirelessly transmit a signal detected by the search coil.

The invention relates to a device and method for detecting sparse pulse by utlizing a vortex finder, exactly, the induced flux caused by pipeline defect is preferentially detected by utlizing the vortex finder, a search coil and a Hall sensor, so that the general pipeline defect and the specific pipeline defect can be simultaneously detected. According to the invention, the average thickness of a pipeline coverd with a thermal insulation material or thick pipeline is measured by a large diameter induction coil, and any local defect of the pipeline can be detected by the Hall sensor located in the central part. The quantitative measurement of pipeline wall thickness reduction can be improved, and any defect can be detected in a simple processing manner without professional operation.

A power converter including: a transformer; a primary-side full-bridge circuit including a primary-side coil of the transformer and a magnetically-coupled reactor, in which two reactors connected to both ends of the primary-side coil are magnetically coupled; a first port connected to a positive electrode bus bar of the primary-side full-bridge circuit; a second port connected to a tap of the primary-side coil; a secondary-side full-bridge circuit including a secondary-side coil of the transformer; a third port connected to a positive electrode bus bar of the secondary-side full-bridge circuit; a first search coil wound around a core of the magnetically-coupled reactor; a second search coil wound around a core of the transformer; and a detection circuit detecting voltages of the first port and the third port by measuring a variation in a sense voltage generated by combining voltages of the first search coil and the second search coil.

The invention discloses a self-starting method of a bi-directional wireless power transmission system based on the detection of a searching coil. The method is suitable for the self-starting of a noncontact power bi-directional transmission system. Taking the power flowing from a side 1 to a side 2 as an example, at the starting stage of the system, the phase information of a high-frequency inversion voltage at the side 1 is acquired by using a sampling resistor at the side 2 and used as an input of a controller at the side 2, so that the controller at the side 2 outputs a control pulse meeting the phase requirement of the system. After the self-starting process of the system is completed, the controller at the side 2 generates a turn-off signal to cut off the sampling resistor, so that the consumption on the sampling resistor when the circuit works normally can be eliminated; meanwhile, the input voltages at the side 1 and the side 2 are converted to a normal voltage stage so as to execute the high-efficient wireless bi-directional transmission of the energy.

A method for measuring an apparent density of a metal powder includes holding a metal powder in a vessel, applying an alternating magnetic flux to the metal powder using an exciting coil disposed outside the vessel, detecting the alternating magnetic flux passed through the metal powder using a search coil disposed outside the vessel, and determining an apparent density of the metal powder from an amplitude of the detected alternating magnetic flux using a calibration curve representing a correlation between the apparent density of the metal powder and the amplitude of an alternating magnetic flux prepared in advance. The method enables to measure the apparent density of a metal powder with a high precision in an on-line and non-contact manner without stopping a process of producing a mixed powder or a process of producing a powder compact.

A magnetic detector includes permanent magnets that magnetize a wire rope W in the longitudinal direction, and a search coil that detects a change in the cross sectional area of the wire rope W magnetized by the permanent magnets. The magnetic detector is provided so as to surround a part of the wire rope W. Prior to inspection, the magnetic detector is moved back and forth at least three times across an inspection range of the wire rope W. After the magnetic detector is moved back and forth, the change in the cross sectional area, that is, damage to the wire rope W is inspected by using signals outputted from the search coil.

A method for parameter estimation in an electromagnetic actuator having a main coil and a search coil includes driving a current through the main coil, determining a main coil voltage, determining a search coil voltage, determining a main coil current, and estimating at least one parameter of the actuator based on the main coil voltage, the search coil voltage and the main coil current.

Provided is a wire rope flaw detector including a magnetizer configured to form a main magnetic flux in a part of a wire rope in a longitudinal direction thereof. A plurality of search coils are configured to detect a leakage flux that occurs from a damaged part of the wire rope in a segment in which the main magnetic flux is formed. A control unit is configured to detect induced voltages generated in the plurality of search coils. Further, the control unit is configured to superimpose voltage waveforms of the plurality of search coils on one another while shifting the voltage waveforms by a time calculated based on an interval between the plurality of search coils adjacent to each other and on a relative moving speed of the wire rope with respect to the magnetizer, to thereby amplify a peak of the induced voltage.