158results about "Active shielding" patented technology

The present invention relates to a magnet-shunted system for shielding a target from magnetic fields and waves. More particularly, the present invention relates to a magnet system including a path member and a magnet member having a magnet at least partially shielded by a magnetically permeable shunt member. The path member forms a path through which the extrinsic magnetic fields and waves bypass the target, the magnet member serves as a termination point for the magnetic fields or waves, and the shunt member defines another path through which primary magnetic fields generated by the magnet member are confined very close to the shunt and / or magnet members. The present invention relates to various methods of forming the termination point, eliminating the extrinsic magnetic fields or waves by the magnet, and disposing the magnet member into the path member. The present invention also relates to various processes for providing such a magnet-shunted system including the foregoing magnet and path members along with the optional shunt member.

Meeting todays requirement in power supply technology demands significant technological advancement in optimizing circuit topology, components and materials, thermal and packaging designs. These requirements are being pushed mainly by continuously increasing power density and efficiency requirements. Ultimately, these trends will come to a point whereby limitations from the above mentioned technological advancements is dependent on one of the above, which is the packaging design. To realize this dependence, we need to look at the growing power systems for modern equipment out there. Let us enumerate some of the available AC adapters in terms of power densities of a 45 W adapter. Firstly, square type architecture introduced by Apple is about 7 W / in3, considering the packaging has a profile limitation whereby its AC plug is removable thus occupying relatively bigger chunk of the volume. The next one is by Asus of similar profile to Apple incorporating the AC Plug eliminating the socket assembly in the packaging; which packs about 9 W / in3. Lastly, the typical rectangular profile by Eos which is about 7 W / in3. As for this particular embodiment it is about 40% smaller in profile, in contrast to the 45 W Apple packaging, with increase power density of about 12 W / in3. Packaging design method plays a great role in achieving the above requirements for a very high density converters.

A pocket incorporated into a garment or accessory provides shielding for wireless communication and other electronic devices and allows insertion and extraction of a wireless communication or other electronic device from the pocket in a simple and natural motion while avoiding compromise of the fit, appearance or function of the garment or accessory.

Systems and methods of shielding a hand sensor system in a steering wheel are disclosed herein. An exemplary hand sensor system includes a sensor mat and a heater mat that is disposed between the sensor mat and a frame of the steering wheel. A power source selectively provides a heating current to the heater mat to provide heat to the steering wheel and a shielding voltage signal to the heater mat to provide electrical shielding for the sensor mat when heating is not needed or when sensing takes priority over heating. Alternatively, the system may include a shield mat that is separate from the heater mat and is disposed between the sensor mat and the heater mat. In addition, to isolate the signal carried by individual sensor return wires, a metallic or insulating covering or conduit may be provided around the wires or portions thereof.

The present invention relates to an electromagnetically-countered system including at least one wave source irradiating harmful electromagnetic waves and at least one counter unit emitting counter electromagnetic waves for countering the harmful waves by such counter waves. More particularly, the present invention relates to generic counter units of electromagnetically-countered systems and to various mechanisms for countering the harmful waves by the counter units such as, e.g., by matching configurations of the counter units with those of the wave sources, matching shapes of such counter waves with shapes of the harmful waves, and the like. The present invention also relates to various methods of countering the harmful waves with the counter waves by such source matching or wave matching and various methods of providing the counter units as well as counter waves. The present invention further relates to various processes for providing such systems, such counter units thereof, and the like. The present invention relates to various electric and / or magnetic shields which may be used alone or in conjunction with such counter units to minimize irradiation of the harmful waves from the system.

An apparatus and process are provided for reducing the electromagnetic field intensity in selected regions for a field produced when ac current flows through one or more induction coils through which a workpiece moves for induction heating of the workpiece. The electromagnetic shield has transverse screen elements through which the workpiece moves at opposing ends of the one or more induction coils. One or two longitudinal screen elements connect the transverse screen elements.

A magnetic shielding device includes: a passive shield having an inner space; a first coil that cancels a magnetic field entering in the inner space; a first magnetic sensor that measures the magnetic field entering in the inner space; a second magnetic sensor located in a position farther from the first coil than the first magnetic sensor; and a controller that controls the first coil so that a gradient between a first magnetic field measured by the first magnetic sensor and a second magnetic field measured by the second magnetic sensor be less than a predetermined threshold.

A magnetic field measurement system includes a wearable device having a plurality of wearable sensor units. Each wearable sensor unit includes a plurality of magnetometers and a magnetic field generator configured to generate a compensation magnetic field configured to actively shield the plurality magnetometers from ambient background magnetic fields. A strength of a fringe magnetic field generated by the magnetic field generator of each of the wearable sensor units is less than a predetermined value at the plurality of magnetometers of each wearable sensor unit included in the plurality of wearable sensor units.

The embodiment of the invention relates to a wave absorbing device with an adjustable frequency. The wave absorbing device with an adjustable frequency comprises a reactance adjustable varactor with a wave absorbing metamaterial, and a master control unit for adjusting the varactor, wherein the varactor is arranged on each metamaterial unit. The wave absorbing device provided by the invention can control the varactor arranged on each metamaterial unit through the master control unit to further adjust the equivalent electromagnetic parameters of each metamaterial unit, so that the wave absorbing material meets the impedance matching characteristics and attenuation matching characteristics for incident electromagnetic waves with different frequencies. And the wave absorbing device has a wider wave absorbing frequency band and a higher wave absorbing efficiency.

An EMI noise reduction board using an electromagnetic bandgap structure is disclosed. In the EMI noise reduction board according to an embodiment of the present invention, an electromagnetic bandgap structure having band stop frequency properties can be inserted into an inner portion of the board so as to shield an EMI noise, in which the portion corresponds to an edge of the board and in which the EMI noise is conducted from the inside to the edge of the board and radiates to the outside of the board.

A magnetic shielding apparatus includes: a passive shield; a correction target space that is defined in the interior of the passive shield; external coils as a first coil that corrects a magnetic field in the passive shield; a first magnetic sensor; a second magnetic sensor that is arranged more inside the passive shield than the first magnetic sensor; and a control unit. The first magnetic sensor and the second magnetic sensor measure a magnetic field gradient in the passive shield. The control unit controls the external coils based on a result of the measurement performed by the first magnetic sensor and the second magnetic sensor.

The invention relates to a device capable of realizing magnetic field shielding without changing surrounding magnetic field distribution. The device comprises a power source 1, a key 2, a resistor 3, an electromagnet 4, a circular ring 5 and a circular ring 6. The device is characterized in that the power source 1, the key 2, the resistor 3 and the electromagnet 4 are connected in series, connection and disconnection of the power source 1 are controlled by the key 2, the electromagnet 4 generates a uniform magnetic field, the circular ring 5 is prepared by a Cr-doped NdFeB material, the circular ring 6 is prepared by a NdFeB material, the two circular rings tightly contact, and the whole device is in an air environment. When relative magnetic permeability and inherent magnetization intensity of the circular ring 5 and the circular ring 6 and the radius dimension relation of the device satisfy conditions that magnetic field shielding and no magnetic field distribution change are realized, the device can realize magnetic field shielding and no influence on surrounding magnetic field distribution, so normal operation of the electrical and electronic equipment is not influenced by an external electromagnetic field.

The invention relates to a broadband adjustable graphene electromagnetic wave absorbing material and a preparation method thereof. The preparation method comprises the following steps: preparing fourkinds of single-layer graphene oxide with different sizes, and then reducing the graphene oxide; attaching the reduced graphene oxide to a conductive medium to form a first electromagnetic wave absorption interlayer; preparing a graphene thin film as a surface electrode by adopting a chemical vapor deposition method, and preparing an oxide thin film as a dielectric layer on the graphene thin filmby adopting an electron beam evaporation coating method to form a second layer of wave-absorbing sandwich structure; fusing a semiconductor oxide and a conductive polymer to form a third layer of wave-absorbing sandwich structure; and forming a three-dimensional structure graphene oxide wave-absorbing material as a fourth layer of wave-absorbing structure through hydrothermal reaction. Different voltages are given to the top-layer graphene and the bottom-layer graphene, so that the absorption performance of electromagnetic waves is regulated and controlled. The invention aims to prepare the efficient, stable and adjustable electromagnetic wave absorbing material by using a simple method, and the purpose of active adjustability is achieved for different environments.

The invention discloses a magnetic field shielding cover of a cusped magnetic field thruster, and belongs to the field of electric thrusters. The problem that the cusped magnetic field thruster is too high in periphery magnetic induction intensity to cause serious disturbance to satellite electronic equipment is solved. The magnetic field shielding cover comprises a bottom plate, a cylinder body and a cover body. The cylinder body is of a cylinder structure with the uniform diameter. The bottom plate arranged at a lower port of the cylinder body and the cylinder body are integrally machined and formed. The center position of the bottom plate is provided with a ceramic inlet installation hole. An upper port of the cylinder body is provided with the cover body. The cover body is of a cylinder structure in a circular truncated cone shape. A large port of the cover body and the upper port of the cylinder body are welded together, and a small port of the cover body is used as a ceramic outlet installation hole. The included angle alpha between the circular truncated cone generatrix of the cover body and the bottom face of the cover body is larger than the largest plume angle of the thruster, and the circular truncated cone generatrix of the cover body is perpendicular to the circular truncated cone generatrix of the outlet section of a discharge ceramic channel.

According to various implementations, a sensor mat includes a mat substrate, a sensor electrode, and a shield electrode. At least a portion of the sensor and shield electrodes are spaced apart from and parallel to each other on a first surface of the mat substrate. The shield electrode is electrically coupled to a voltage source to create a capacitance between the shield electrode and the sensor electrode, and the sensor electrode is used to detect a change in the capacitance. The shield electrode may also be alternately used for heating the surface of the vehicle part adjacent the mat. For example, the sensor may be disposed adjacent a portion of a steering wheel or a seat assembly and is used for sensing presence of an occupant's hands or body adjacent the steering wheel or seat assembly.

The invention relates to a hybrid magnetic shielding device based on a high temperature superconducting coil. The invention aims at providing a shielding device which has a good shielding capability, has no amplitude dependent performance and is convenient to move. The device comprises an upper computer, a flux-gate meter, three high precision current sources, a superconducting ring and a triaxial Helmholtz coil. A control signal output terminal of the upper computer is connected to control terminals of an x axis high precision current source, a y axis high precision current source and a z axis high precision current source respectively. Current output terminals of the x axis high precision current source, the y axis high precision current source and the z axis high precision current source are connected to three coils with different dimensions on the triaxial Helmholtz coil respectively. A center position of the triaxial Helmholtz coil is provided with the superconducting ring. A center position of the superconducting ring is provided with a three-dimensional flux-gate probe. A signal output terminal of the three-dimensional flux-gate probe is connected to a signal receiving terminal of the flux-gate meter. A signal output terminal of the flux-gate meter is connected to a feedback signal receiving terminal of the upper computer.

The invention relates to the technical field of wireless charging, in particular to a dynamic active flux leakage shielding device and method. The device comprises a magnetic field detecting unit, anexcitation source and an excitation coil; the magnetic field detecting unit is used for detecting the intensity of a leakage magnetic field and acquiring a flux leakage compensation value; and the excitation source is used for driving the excitation coil to generate a magnetic field of the compensation value to counteract the leakage magnetic field. Leakage magnetic flux can be adjusted dynamically, flux leakage transmission is reduced greatly on the premise of not affecting transmitting power and efficiency of a wireless magnetic field, and influence of flux leakage radiation to human bodiesis relieved.

The present invention relates to a method and apparatus of protecting magnetically sensitive devices with a shield, including: a non-superconducting metal or lower transition temperature (Tc) material compared to a higher transition temperature material, disposed in a magnetic field; means for creating a spatially varying order parameter's |Ψ(r, T)|2 in a non-superconducting metal or a lower transition temperature material; wherein a spatially varying order parameter is created by a proximity effect, such that the non-superconducting metal or the lower transition temperature material becomes superconductive as a temperature is lowered, creating a flux-free Meissner state at a center thereof, in order to sweep magnetic flux lines to the periphery.

The invention discloses a graphene-based infrared transmission electromagnetic shielding filter, a zinc sulfide window and a fabrication method of the graphene-based infrared transmission electromagnetic shielding filter. The fabrication method comprises the following steps of growing a graphene thin film Gr on a surface of a copper foil; spraying a macromolecule transition layer TL at one side of the graphene thin film, and obtaining a copper coil / Gr / TL composite body after curing; spraying a liquid-state polymethyl methacrylate (PMMA) at one side of the macromolecule transition layer; etching the copper foil; transferring a Gr / TL / PMMA composite body to an inner surface of the zinc sulfide window; and dissolving the macromolecule transition layer, and separating a PMMA carrier from the graphene thin film to obtain a ZnS / Gr composite body until the electrical performance of the graphene thin film at an inner side of the zinc sulfur window conforms to the electromagnetic shielding requirement and the graphene-based infrared transmission electromagnetic shielding filter is finally formed on the surface of the inner side of the zinc sulfur window. The graphene-based infrared transmission electromagnetic shielding filter is high in infrared transmission and is easy to fabricate.

The present invention relates to an electromagnetically-countered display system including at least one wave source and at least one counter unit, where such a wave source irradiates harmful electromagnetic waves and the counter unit emits counter electromagnetic waves for countering the harmful waves therewith. More particularly, the present invention relates to various counter units for the electromagnetically-countered display system and to various mechanisms to counter the harmful waves with the counter units, e.g., by matching configurations of the counter units with those of the wave sources, by matching wavefronts of the harmful waves with those the counter waves, and so on. The present invention also relates to various methods of countering the harmful waves with such counter waves by source and / or wave matchings, various methods of providing the counter units for emitting the counter waves defining desired wave characteristics, and the like. The present invention further relates to various processes for providing the electromagnetically-countered display systems and their counter units. The present invention further relates to various electric and magnetic shields employed either alone or in conjunction with the counter units for minimizing irradiation of the harmful waves from the shaving system.

An electromagnetically-countered display system includes at least one wave source and at least one counter unit. The wave source irradiates harmful electromagnetic waves and the counter unit emits counter electromagnetic waves for countering the harmful waves therewith. Examples of the various counter units for the electromagnetically-countered display system and various mechanisms to counter the harmful waves with the counter units include by matching configurations of the counter units with those of the wave sources, and by matching wavefronts of the harmful waves with those the counter waves. Various methods of countering the harmful waves with such counter waves include by source and / or wave matching. Various methods of providing the counter units for emitting the counter waves defining desired wave characteristics. Various electric and magnetic shields can be employed either alone or in conjunction with the counter units for minimizing irradiation of the harmful waves from the display system.

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.

The invention belongs to the technical field of inertial navigation systems, and particularly relates to a magnetic shielding device for a biaxial-rotation fibre-optic inertial navigation system. The magnetic shielding device for the biaxial-rotation fibre-optic inertial navigation system disclosed by the invention comprises a gyroscope shielding layer and an outer shielding layer, wherein the gyroscope shielding layer is used for directly shielding an fibre-optic gyroscope and is installed on an installation surface corresponding to an inertial assembly together with the fibre-optic gyroscope; the whole inertial assembly is surrounded by the outer shielding layer to form a double-layer magnetic shielding structure. The magnetic shielding device disclosed by the invention is capable of effectively isolating the motor magnetic field in the inertial navigation system, and realizing magnetic shielding protection on the rotating inertial assembly, thus reducing the magnetic field intensity around the fibre-optic gyroscope, and improving the navigation accuracy of the inertial navigation system.