1271 results about "Electromagnetic compatibility" patented technology

Improved electromagnetic compatibility for integrated motherboard or device board designs is provided by magnetic shielding, electric shielding, or both integrated into the chip packaging materials. Motherboard emissions may be reduced by use of the shielding. A nonconductive primary and tertiary layer sandwich a high-conductivity metal secondary layer forming a Faraday cage for electric field shielding. A nonconductive primary layer is covered by a tertiary layer formed of a composite having permeable material for magnetic shielding. The tertiary layer formed of a composite could include a high permeability particulate ferrous material. Both the secondary layer and the tertiary layer formed of a composite could be used for both electric and magnetic shielding of chips.

The invention provides a method for testing electro-magnetic compatibility of an automotive CAN (controller area network) bus based on semi-physical simulation, belonging to the technical field of design and development of electro-magnetic compatibility of an automobile. The method comprises the following steps: step 1. building an automotive empty shell table frame of which the full size is 1:1 according to the actual situation of the electro-magnetic compatibility of the automobile; step 2. simulating and injecting the interference signals; step 3. monitoring the response of the automotive CAN bus on the interference signals; step 4. estimating the EMC (electro-magnetic compatibility) property of the CAN bus by using an estimating system; and step 5. observing the electro-magnetic compatibility of the automotive CAN bus in real time. With the adoption of the method, the shortcoming of the traditional method for testing the electro-magnetic compatibility of the automotive CAN bus is made up. Based on a forecasting platform of the semi-physical simulation of the electro-magnetic compatibility, research staff can implement the electro-magnetic compatibility design at various development stages such as the scheme formulating, sample manufacturing, sample testing, and testing of the system, so that the problems that the traditional electro-magnetic compatibility design is not complete and the electro-magnetic compatibility rectification has no effect can be solved.

The invention provides a primary side-controlled constant current switch power supply controller and a primary side-controlled constant current switch power supply control method. The controller comprises a current sampling end, a grounded end, a power supply end, a driving end, a voltage feedback end, a frequency setting end, a first sampling hold module, an average current ring module, a saw-tooth wave generation module, a comparison module, a second sampling hold module, a voltage/frequency conversion module, a driving pulse generation module and a driving module. The controller has a simple structure and can be used for realizing a high-power factor within a full-input voltage range while constant current is output; in addition, when output voltage is unchanged, work frequency of the circuit is basically constant, so that the work frequency meets the electromagnetic compatible standard more easily. The primary side-controlled constant current switch power supply controller and theprimary side-controlled constant current switch power supply control method can also be used for a direct-current input low-power power supply without requirement on a power factor so as to realize constant current output.

The invention discloses a wave energy and solar energy driven unmanned monitoring ship for a marine environment, which comprises a ship body and an unmanned control system, wherein the ship body has a shape of rigid inflatable boat; the unmanned control system comprises a ground remote control system and a ship-loaded system which are coupled with each other through a wireless data link; the ground remote control system comprises a remote control computer, a wireless network bridge and corresponding top-layer application software; the ground remote control system is used for receiving, analyzing and displaying a ground remote control command and data; a serial port of the remote control computer is connected to the wireless network bridge; and the ship-loaded system comprises a navigationcontrol subsystem, a communication subsystem, a navigation information sensing and collecting subsystem, a wave energy and solar energy power generating and supplying subsystem and a data collecting subsystem. No diesel motor is required in the wave energy and solar energy driven unmanned monitoring ship, a wave energy generating system and a solar energy generating device of the ship are directly used for supplying power, the quality of output electric energy is stable and the electromagnetic compatibility is excellent, thereby ensuring the normal work of ship-loaded equipment under a complex marine environment.

A power supply for a Light Emitting Diode (LED) traffic signal that controls the light intensity. The light intensity conforms to a predetermined pattern based on the input voltage root mean square value (V_rms). The input voltage is changed by acting on the amplitude of the sine wave or by using a triac and controlling the angle of fire. The power supply comprises a fuse module, an electromagnetic compatibility filter module, a power supply module, a LED load module, a current monitor module, a RMS-DC conversion module and a fuse blow out module.

The invention discloses a fuel cell vehicle multi-source controller and a control method thereof. The fuel cell vehicle multi-source controller functionally comprises communication among a fuel cell engine controller, a vehicle controller and a vehicle intelligent control system; the fuel cell vehicle multi-source controller achieves interaction and control of input information between a fuel cellstack, a cell stack operation monitoring device, a cell stack operation environment control device, a controller body, an upper computer, a fuel cell system and the whole vehicle and the outside. Thefuel cell vehicle multi-source controller and the control method thereof solve the problems that the fuel cell engine controller and the vehicle controller of an existing fuel cell vehicle are independently designed and operated in software and hardware to impede resource integration, to result in resource waste as well as difficulty in cost reduction, to go against comprehensive demand design offunctional safety, electromagnetic compatibility, safety redundancy and intelligent control on chips and systems and to increase the system risk.

The invention discloses a symmetrical half-bridge LLC resonant bidirectional DC-DC converter, which belongs to the technical field of power electronic application. Topological structures on the two sides of the converter are symmetrical, and adopted components adopt a complex function design. When a switching network and a resonant network on one side of a high frequency transformer function, the switching network and the resonant network on the other side are automatically evolved into a rectifier-load network, and the networks on the two sides commonly form the whole LLC resonant converter to realize power conversion in a corresponding direction. Because the structures are completely symmetrical, reverse conversion can be possible; and in the reverse conversion, the topological structures can be automatically reconstructed to form a reverse LLC resonant converter to realize reverse power conversion. The symmetrical half-bridge LLC resonant bidirectional DC-DC converter achieves effective improvements in conversion efficiency, power density, dynamic performance and electromagnetic compatibility, reduces the electrical stress of components at work, has a reduced volume and a reduced weight, and realizes highly-efficient, isolated and bidirectional DC/DC power conversion.

he invention discloses a mixed excitation biconvex pole motor, including rotors, stators, three-phase armature windings and a case, wherein, the case is in magnetic conduction material, the rotor is composed of alveolar type core lamination, the stator fixed in the case includes 'U'-shaped cores arranged with interval between each other and permanent magnets provided between the 'U'-shaped cores and the case, the first permanent magnet charges magnetism tangentially along the circumference, N pole and S pole are arranged alternately, a second permanent magnet is provided between the 'U'-shaped core base and the case, the second permanent magnet charges magnetism along the radius direction, N pole and S pole are arranged alternately, the three phase armature winding is a concentrated winding, winding on the armature teeth, the armature teeth are composed of adjacent two edges of two 'U'-shaped cores, the single-phase excitation is a concentrated winding, winding on the 'U'-shaped core and the permanent magnet. In the inventive mixed excitation biconvex pole motor, the permanent magnet excitation and exciter winding electric excitation jointly combine an air-gap field to realize the adjustability of air-gap field, and simultaneously adopts magnetic conduction material as the case so that it can avoid the leakage of case outer edge, improves the motor anti-electromagnetic interference and electromagnetic compatibility, and improves utilization of permanent magnets.

A radio frequency module with a SAW package mounted on the substrate is provided in a low profile structure also having excellent resistance to noise or in other words, electromagnetic compatibility even when a resin-sealed SAW package is utilized. Organic laminate of at least a single layer is used as the substrate of the radio frequency module, and a throughhole is formed on that organic laminate. The resin-sealed SAW package that encloses a flip-chip mounted SAW filter is mounted so that the ceramic substrate is positioned mainly outside the throughhole, and the SAW filter is positioned mainly inside the throughhole. A grounding conductor is formed on the rear side or the inner layer in the vicinity of the throughhole.

A wireless local area network adapted for use by users traveling on a mobile platform such as an aircraft. The network includes a network server located on the mobile platform, and at least one network access point connected to the server and accessible wirelessly by at least one user portable electronic device over one of a plurality of non-overlapping network frequency channels. The RF characteristics of this wireless network are specifically tailored to meet applicable standards for electromagnetic compatibility with aircraft systems and RF exposure levels for passengers and flight crews.

The invention provides a driving method and a device for adjusting LBD brightness with high power; the method can obtain the LBD brightness data through receiving the control information input from the outer side; the current flowing through the LBD can be set through a current adjusting unit connected with the driving unit, the LBD is lighted so as to lead the brightness to reach the target value; or the current flowing through the LBD can be set according to the method, the LBD brightness can be primarily adjusted, and then the signal dutyfactor of the PWM adjusting unit connected with the current adjusting unit in parallel is set, the LBD brightness is further adjusted to finally reach the target value; the LBD can be turned off through setting the dutyfactor of PWM adjusting unit signal to 0%. the technical proposal provided by the invention is utilized to dynamically adjust the LBD brightness in real time, and remarkably improve the EMC (electromagnetic compatibility) property of the device at the same time, and prolong the service life of the LED.

The invention belongs to an electromagnetic compatibility fault diagnosis method and particularly relates to an interference source identification method in a system-grade electromagnetic compatibility fault diagnosis. The interference source identification method is characterized by comprising the following steps of: step 101, utilizing positioning sensitive equipment; step 102, carrying out fault tree analysis on the positioning sensitive equipment; step 103, performing the fault tree analysis so as to obtain a priority level of a coupling path; step 104, testing to obtain interference testing data; step 105, storing the testing data into a database; step 106, obtaining a potential interference source through the fault tree analysis of the step 102; step 107, searching and determining the priority level of the interference source; step 108, combining the step 105 and the step 107 to identify the interference source; step 109, judging whether the interference source is a determined interference signal or not; if not, carrying out step 110; otherwise, carrying out step 111; step 110, carrying out environment monitoring; and step 111, obtaining the determined interference signal and finally, finishing the compatibility fault diagnosis. The interference source identification method in an electromagnetic compatibility fault diagnosis system has the advantages of convenience for use, short period, low cost and controllable faults.

An electromagnetic compatibility test method for electric propulsion system comprises the following steps: wave transparent rate of wave transparent subsidiary cabins of electric propulsion system is measured; steady state and transient state electric field radiation of electric propulsion system and steady state power line conducted emission are measured; spike of power line when electric propulsion system is in transient state working condition is measured; conduction of fictitious load and radiation emission characteristic and actual thrustor are compared and measured; influence of plume to communication is measured to obtain electromagnetic compatibility test data of electric propulsion system. The inventive method is not required to be carried out in an electromagnetic compatibility laboratory, and can be tested on out-field or working site of electric propulsion system, the test result has little error and can authentically reflect electromagnetic compatibility of the propulsion system, thus greatly lowering test cost and improving working efficiency.

The invention relates to a flexible heat conduction interface material with a wave absorbing function, which comprises the following components in parts by mass: 100 parts of vinyl silicone oil, 100 to 1,000 parts of a heat conducting filler, 100 to 1,000 parts of a wave absorbing material, 1 to 50 parts of hydrogen-containing silicone oil, 0.01 to 1 part of a platinum catalyst, and 0.01 to 1 part of an inhibitor. The flexible heat conduction interface material has the advantages that a high-thermal-conductivity caulking interface is produced by a mixture prepared by mixing the vinyl silicone oil, the heat conducting filler, the wave absorbing material, the hydrogen-containing silicone oil, the platinum catalyst and the inhibitor; due to addition of the wave absorbing material, the mixture has an excellent electromagnetic parameter, and the electromagnetic parameter of the mixture can be achieved by regulating a particle size of micro particles of the wave absorbing material; and the flexible heat conduction interface material is beneficial to impedance matching and widening of an absorption band and can meet the requirements of the electron and communication industries for high-efficiency energy conduction and electromagnetic compatibility. In addition, the invention further provides a preparation method of the flexible heat conduction interface material with the wave absorbing function.

A gasket retainer is mounted on a connector body to hold a rounded conductive gasket in position around an open end of the connector body. The gasket retainer has an elongated body with an upper surface, a lower surface and a central open portion to form an outer peripheral portion, surrounding the central open portion, having two side edges and two end walls. Gasket retaining portions, which may be a number of fingers extend upwardly away from the upper surface of the two side edges and recesses are formed in the two end walls to allow holding portions on the connector body to secure the retainer adjacent the open end with the rounded conductive gasket held in position, flush against the connector body to improve the shielding effectiveness in fibre channel SFP transceiver electro magnetic compatibility when connected.

The invention provides a USB (Universal Serial Bus) interface circuit which comprises a USB connector, a power common mode filter module, a signal common mode filter module, a power differential mode filter module, a signal differential mode filter module and an electrostatic protection module. Common mode interference, differential mode interference, electrostatic interference and the like on a power line and a signal line in the circuit can be eliminated; particularly, the additionally arranged power common mode filter module can eliminate common mode interference between a power VBUS and a working ground GND; and the circuit is small in size, low in cost and high in practicability, has very good protection effects on electrostatic discharge (ESD) and electromagnetic interference (EMI), allows a USB signal to be free from distortion, and ensures that a product smoothly passes USB certification and EMC (Electromagnetic Compatibility) certification. In addition, a high-voltage protection module and a high-frequency filter module can eliminate high-voltage signal interference and high-frequency signal interference in the circuit, so that the interference resistance of the USB interface circuit is further improved, and the signal transmission performance of the USB interface circuit is improved.

The invention discloses a radiation electromagnetic compatibility test method for an electric propulsion system and on-star radio frequency equipment. Firstly, an ion thruster is arranged in a wave transmitting secondary cabin; the wave transmitting secondary cabin is connected with a main vacuum tank; and electromagnetic radiation interference produced by a plume of the ion thruster is emitted out of the main vacuum tank through the wave transmitting secondary cabin. Each equipment and antenna are connected. When the electric propulsion system is started to normally work, both uplink level and downlink level of a responder are weak levels; conditions of uplink instruction reception and downlink remote metering error code are checked; if the instruction reception is correct, the code ratemeets the requirement and the responder is not interfered; remote metering parameters for a GPS (Global Positioning System) receiver are observed, and absolute positioning condition and relative positioning condition are determined; and if the remote metering is correct and the positioning is normal, the GPS receiver is not interfered.

Electromagnetic compatibility of an information handling system and peripheral for achieving defined electromagnetic interference constraints is tested through a test adapter that interfaces with an external cable connecting the information handling system and peripheral. Signals from the external cable are passed through an isolation resistor and parallel capacitance to compensate for input capacitance of a signal tester. A common mode choke isolates a common mode component of the signal at the external cable. A noise generator applies a signal through the test adapter to the external cable to allow measurement of signals emitted from the peripheral due to injected noise.

The invention provides a high-gain ultra-wideband corrugated double-ridge horn antenna with a loaded lens and belongs to the technical field of microwave antennas. The high-gain ultra-wideband corrugated double-ridge horn antenna is used for solving the problem that the double-ridge horn antenna is low in gain, and a high-frequency directional diagram is disintegrated. The high-gain ultra-wideband corrugated double-ridge horn antenna comprises a coaxial feed connector (1), a rectangular waveguide (2), a corrugated horn (3), a double-ridge waveguide (4) and the dielectric lens (5). The dielectric lens (5) of a hyperbolic structure is arranged at the position of a front port of the corrugated horn (3), the focus of the dielectric lens (5) coincides with the center of an antenna feed, a rear port of the corrugated horn (3) is connected with the rectangular waveguide (2), and the double-ridge waveguide (4) is arranged in the corrugated horn (3). The coaxial feed connector (1) is installed at the upper portion of the rectangular waveguide (2), and plane corrugations are arranged on the surface of the rear portion of the inner side of an upper metal plate (7) and the surface of the rear portion of the inner side of a lower metal plate (7). The high-gain ultra-wideband corrugated double-ridge horn antenna has the advantages that the ultra wide band, the high gain and the stable directional diagram are achieved in the 1-18 GHz area, and the high-gain ultra-wideband corrugated double-ridge horn antenna is suitable for the fields of electromagnetic compatibility tests, reflector antenna feed sources, ultra wide band radars and the like.

The invention relates to a circuit for eliminating noise of a switching power supply. The circuit comprises a transformer, a primary winding of the transformer is connected with an alternating current input end, a secondary winding is connected with a direct current output end, and the circuit further comprises at least one group of symmetrical Y capacitors, wherein a first Y capacitor in the group of the symmetrical Y capacitors is respectively connected with the positive input end of the alternating current input end and the negative output end of the direct current output end, and a second Y capacitor is respectively connected with the negative input end of the alternating current input end and the negative output end of the direct current output end. By arranging the symmetrical Y capacitors, not only can the purpose of eliminating the noise be achieved, but also the characteristics of high efficiency and good EMC (electromagnetic compatibility) performance can be realized in comparison with the prior art. In addition, the circuit for eliminating the noise has the advantages that the volume of the switching power supply can reduced and the cost and process are reduced in comparison with a 3Pin input structure in the prior art; and furthermore, the circuit has universal practicability in strong plug-in connection type power supplies.

The invention relates to the field of electromagnetic compatibility, in particular to a system and a method for modeling printed circuit board level conducted electromagnetic interference. Conducted interference of a power wire port of a certain control circuit board is quantitatively analyzed by extraction through a circuit model and modular modeling. Interference noise sources, equivalent resistance R, inductance L, capacitance C, conductance G parameters and internal logic circuits of devices are acquired by respectively calculating and equalizing circuits, main interference chips, power modules and the like on the circuit board, modular package is performed, so that an equivalent circuit model of the whole power system is built, and conducted interference waveforms and quantitative spectra of points on a power wire can be obtained by circuit simulation. Conducted electromagnetic interference frequency and amplitude of key circuits on the printed circuit board can be quantitatively analyzed at a pre-design phase, portions with poor electromagnetic compatibility are found and optimized, the electromagnetic interference degree of the whole circuit board is reduced, and research and development cycle and cost can be reduced.

The invention discloses a three-level temperature control system of an inertia measurement system. A gradient temperature difference control mode is adopted, temperature control of an inertia instrument is added on the basis of original first-level or second-level temperature control, three-level temperature control is achieved, and the three-level temperature control system controls a box body, an installing table body and the inertia instrument respectively, therefore, the influence of the outside environment temperature change on the accuracy of the inertia instrument is reduced to the maximum, the temperature gradient inside the inertia measurement system is effectively reduced through the three-level temperature control, the inertia measurement system can normally work under wide temperature environmental conditions to achieve stable working temperature, accuracy of temperature control is improved, and stabilization time of temperature control is shortened. According to the designed three-level temperature control system, a PWM temperature control mode and a digital PID temperature control mode are adopted, high antijamming capacity, stability and electromagnetic compatibility are possessed, and the temperature control system can be matched with a refrigeration fan and refrigeration modes of semiconductor refrigeration and the like for use, and is wide in application range, high in environmental adaptability, and good in stability.

In a flat panel display (FPD), a conductive heat proof plate is inserted between the back surface of a display panel, on which printed circuit boards (PCBs) and signal lines are formed, and signal lines. A back frame positioned on the back surface of the display panel is provided to cover the printed circuit boards and the signal lines. A shield can is formed in the internal surface region of the back frame corresponding to the printed circuit board on which a timing controller is mounted. The shield can is electrically coupled to the heat proof plate to improve resistance against the electromagnetic compatibility of a large flat panel display and to improve a thermal characteristic.

The invention discloses a 1553B bus network emulation system applied to a spacecraft system, which belongs to the field of aerospace and computer emulation. The 1553B bus network emulation system comprises a 1553B bus, the Ethernet, a bus network tester, a bus terminal tester, a digital phosphor oscilloscope, a bus separation switch, an emulation terminal, a bus system performance estimation computer and a bus interface control file configuration computer, and is used for emulating and analyzing the information transmission and system running of an actual spacecraft bus system. The 1553B bus network emulation system replaces conventional cable connection with a 1553B bus network, realizes the digitalized transmission and comprehensive utilization of network system information and improves the reliability and electromagnetic compatibility of the system by equipment with standard digital interfaces in combination with Ethernet communication, meets 1553B specifications, realizes coexistence in one network emulation system, can be used for a plurality of stages of analysis, development, test and the like of the spacecraft system and is of great importance to researches on the reliability of the actual spacecraft system.

An embodiment of the invention discloses a method and a system for transparently transmitting full-IP (internet protocol) visible light data. The method and the system aim to realize electromagnetic compatibility among communication equipment and other electronic devices. The system comprises visible light communication terminals and visible light communication illuminating devices (connected into a power line grid), and IP addresses are distributed to the visible light communication terminals and the visible light communication illuminating devices. Each visible light communication illuminating device consists of a power line router modem and a visible light receiving and transmitting device, and each visible light communication terminal consists of a visible light receiving and transmitting device. Conversion between visible light signals and the IP data meeting TCP/IP (transmission control protocol/internet protocol) requirements can be carried out by the visible light receiving and transmitting devices, so that visible light communication among the visible light communication terminals and the visible light communication illuminating devices is realized, and intercommunication between the power line grid and a VLC (visible light communication) network is realized by the power line router modems. In addition, the visible light frequency band ranges from 400THz to 800THz, the common radio frequency band is avoided, and accordingly the problem of electromagnetic interference among the system and other electronic devices is avoided.

The invention discloses an ambient interference resisting method for testing an electromagnetic radiation emission field. The method specifically includes that a receiving antenna array is arranged in the testing field, each antenna unit can receive mixed signals composed of a tested device radiation signal and an interference signal, and by means of a spatial spectrum estimation method based on a multiple signal classification algorithm (MUSIC), the direction of arrival of each signal is obtained. According to a spatial spectrum estimation result, by means of a minimum variance distortionless response (MVDR) beam forming criterion, each antenna array element receiving signal is subjected to optimal weighting, in the premise that the tested device radiation signal is not distorted, array beams form null steering along the coming direction of the interference signal, and spatial filtering of the interference signal is achieved. According to the ambient interference resisting method, the MUSIC spatial spectrum estimation method and the MVDR beam forming technology are introduced into the field of electromagnetic compatibility testing, so that the ambient interference generated during testing of field radiation emission can be effectively inhibited, and radiation emission characteristics of a tested device in actual work environment can be accurately obtained.

This invention provides one high voltage transducer power unit, which comprises shell, function parts, control board, capacitor array and dissipation part, wherein, capacitor array is put on unit bottom; dissipation device is distributed on one side of capacitor array and other side with control board; there is shield board between control board and power parts with power parts on dissipation surface to connect parts through copper band.

The invention relates to a full electric wave darkroom possessing both aerial radio frequency testing and EMC testing abilities, belonging to the technical field of aerial radio frequency testing darkroom and full electric wave darkroom design for radio equipment. And it comprises shielding casing, wave absorption material layer bonded with inner wall of the casing, false wall, darkroom door, turntable and tested equipment supporting device installed in the casing, antenna bracket system, vent illuminating device, filter, safe and electrical device and interface board to be connected with a tester, where the shielding casing is L-shaped, on two sides of the L shape are OTA testing darkroom and full electric wave darkroom, mutually vertical and interconnected, and a set of turntable and tested equipment supporting device is arranged at the junction of the two darkrooms. And it can reduce darkroom construction cost and raise utilization ratio.

The invention discloses a radio frequency current probe characteristic calibrating method based on electromagnetic compatibility analysis and application and belongs to the field of electromagnetic compatibility analysis and application and electromagnetic interference noise measurement. According to a frequency section needing to be measured, in the method, the transfer impedance of a current probe is tested in a time domain by utilizing a dual-trace oscilloscope and then tested in a frequency domain by utilizing a vector network analyzer and adopting a scattering parameter method; and finally, a measurement conversion coefficient of the current probe can be more accurately obtained. The method has simple operation and accurate test, enables a result of electromagnetic interference noisemeasured by the current probe to be more accurate, and provides a theoretical basis for conducting the electromagnetic interference noise.

An electromagnetic detector for diagnostic - testing compatibility of vehicle internal electromagnetism has electric field probe and magnetic field probe as the two are connected to low noise amplifier respectively through adapter. The detector can be used to diagnose leakage of shielding shell and various components on electronic circuits as well as radiating emission of similar electromagnetic disturbance source, and can be connected to computer through EMI detection receiver.