1362 results about "Electro magnetic compatibility" patented technology

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 discloses a fast electromagnetic compatibility test and diagnosis system with quantization electromagnetic interference. A receiving antenna of the system is arranged on a frequency spectrum tester, a chuck end of a current probe is clamped on a cable through which tested objects are connected, the other end of the current probe is connected on the frequency spectrum tester which is connected with a computer; and the computer is internally provided with a fast electromagnetic compatibility test and diagnosis unit. The fast electromagnetic compatibility test and diagnosis unit is used for fast testing the electromagnetic-transmitted frequency spectrum of the tested objected on site, conducting analysis and diagnosis to the electromagnetic-transmitted frequency spectrum, and judging whether the electromagnetic transmission characteristic exceeds a standard limit value or has abnormality. The fast electromagnetic compatibility test and diagnosis system has important meaning on solving the electromagnetic compatibility problem and monitoring and evaluating the electromagnetic environment.

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.

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 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 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.

The invention discloses a reactive power control circuit of a single-phase photovoltaic inverter. The reactive power control circuit comprises a bus voltage supporting capacitor, a single-phase full-bridge inversion circuit, a filtering inductor, an EMC (Electro Magnetic Compatibility) filtering circuit, a sampling circuit, a power switch pipe driving circuit and a DSP (Digital Signal Processor), wherein the DSP consists of a PLL (Phase Locked Loop) control module, a voltage outer ring PI control module, a current inner ring PI feedforward control module and a sinusoidal PWM (Pulse-Width Modulation) wave sending control module, and an input signal of the sinusoidal PWM wave sending control module of the DSP further includes a current inner ring current given amount Ig. The invention further provides a reactive power control method of the single-phase photovoltaic inverter. The method not only can be used for judging whether the voltage Uac of a power grid is larger than zero, and comparing the absolute value of a PWM wave sending control input modulation wave Upwm with a given triangular carrier wave Uc, but also can be used for judging whether the given current inner ring current amount Ig is larger than zero. Not only can the conduction loss of a power switching tube be reduced, and the conversion efficiency of the inverter is improved, but also the current waveform can be continuous, an output harmonic wave is reduced, and the pollution on a harmonic wave of a power grid is reduced.

An electromagnetic compliant (EMC) shield for shielding electronic components on a circuit board from electromagnetic energy generated by electronics modules inside the EMC shield. The shield also contains electromagnetic energy generated by the electronic components on the circuit board from escaping to outside the EMC shield. The EMC shield includes a first side and a second side. The first side has a plurality of openings. Each of the openings is configured to receive a respective electronics module. The second side has a bottom edge with a groove to receive a conductive gasket. The first and second sides extend normal to the circuit board when the EMC shield is mounted to the circuit board.

The invention relates to a controlling technology for an electric light source, which is a digital and intelligent power source of an electromagnetic induction light which specially provides power source for the electromagnetic induction light. The controlling technology comprises an electromagnetic compatible circuit, a waves filtering rectifier circuit, a correction circuit with source power parameters and an output circuit with a half-bridge drive power which are electrically connected in sequence. Particularly, a digital controlling singlechip is respectively connected with the correction circuit with source power parameters and the output circuit with a half-bridge drive power, a man-machine interface is also connected with the singlechip through an interface circuit, and a sensor group is connected with the singlechip; the power source of the invention simplifies the hardware circuit and has the advantages of flexible control, perfect protection system, lower fault rate, high efficiency of electrical power transformation and more remarkable energy saving effect.

The invention relates to an inverter synchronous grid connection system and an inverter synchronous grid connection method. The inverter synchronous grid connection system comprises a DC (Direct Current) side switch, a DC EMC (Electro Magnetic Compatibility) filter, a bus capacitor assembly, a power module, an inductor, an output filter assembly, an AC (Alternating Current) EMC filter, a grid connection contactor, a soft start circuit and an AC side circuit breaker which are sequentially connected; the soft start circuit is formed by a prechargd contactor, a rectification bridge and a series resistor; one end of the soft start circuit is connected to the bus capacitor assembly at the DC side and the other end of the soft start circuit is connected with the AC side circuit breaker. Voltage and phase values of the bus capacitor assembly are continuously detected and when the voltage and phase values are the same with those of a power grid, grid connected power generation is carried out, and thus, current impact in the grid connection process is reduced and the service lives of devices, particularly an expensive large-current grid connection switch, inside an inverter are obviously prolonged.

The invention provides an EMC (Electro Magnetic Compatibility) test method of a deep space aircraft coupling. The method comprises the following steps of: turning off power of each detector consisting of the aircraft coupling, calibrating EMC test equipment, and testing the background noise of an anechoic chamber; carrying out the electromagnetic radiation and sensitivity test on each detector; analyzing test data of each detector; determining the suppression condition of mutual interference between detectors of the aircraft coupling; and carrying out the EMC test on the aircraft coupling. For the source of electromagnetic interference, by adopting a test method from the point to the surface, the EMC characteristics of the deep space aircraft couplings can be quickly, reliably and safely detected, the source of electromagnetic interference is determined, the electromagnetic interference and the failure are safely and reliably detected, and the EMC test efficiency of the deep space aircraft coupling is improved.

The invention discloses a sealing system. The sealing system comprises a first baseplate, a second baseplate, a first shielding layer, a second shielding layer, a first component and shielded welding balls. The first baseplate and the second baseplate are oppositely arranged. The first shielding layer is arranged on one surface of the first baseplate and faces the second baseplate. The second shielding layer is arranged on one surface of the second baseplate and faces the first baseplate. The first shielding layer and the second shielding layer are both connected with ground or a power supply. The first component is located on the first shielding layer. The shielded welding balls are located on the periphery of the first shielding layer. The sealing system can effectively solve the problem of electro magnetic compatibility (EMC) and improves sensitivity of the system on the premise of not increasing the size of the system.

The invention provides an equalization method and a circuit, and particularly relates to a method for realizing active equalization among battery pack modules and a circuit. The method for realizing active equalization among the battery pack modules includes detecting voltage of the various battery pack modules; sorting the voltage of the battery pack modules; finding the battery pack module with the maximum voltage and the battery pack module with the minimum voltage; and charging the battery pack module with the minimum voltage by the battery pack module with the maximum voltage when voltage difference between the two battery pack modules reaches a set equalization standard voltage difference value. The battery pack module with the maximum voltage charges the battery pack module with the minimum voltage in a constant-voltage current limiting mode, the maximum output voltage is voltage of the battery pack module, and output current is equalizing effective current. By the aid of the method and the circuit, power equalizing devices, inductance devices and the like are omitted, conduction and radiation are effectively controlled, active equalizing current is increased, active equalization efficiency is improved, cost of an equalization module is lowered, and EMC (electro-magnetic compatibility) and EMI (electro-magnetic interference) of the integral circuit are controllable.

The invention discloses an electromagnetic compatibility optimizing method for a receiver in targeted frequency ranges. A plurality of interference devices and a width-band receiver are associated by using simulation software and the simulation computing power of a computer, and comprehensive consideration is given to the interference characteristic of each interference device, the interfered characteristic of the receiver and the spatial isolation degree so as to extract an interference leading source; and the interference leading source is used to systematically perform targeted electromagnetic compatibility optimization on the out-of-band emission of the interference devices, the spatial isolation degree of antennae and the interfered threshold of the wide-band receiver according to the priority. The method defines the optimization target and improves the optimization speed on the premise of ensuring the optimization effect.

The invention provides an electromagnetic compatibility immunity test system used for a key-free system. The system comprises a key signal transmitting device whose key signal transmitting antenna is arranged inside an anechoic chamber, so as to transmit a key signal to a key-free system to be tested which is arranged inside the anechoic chamber, and operation is carried out according to the key signal when the key signal received by the key-free system to be tested is a required working signal. In addition, the test system in the invention also comprises an anti-interference test system whose test signal transmitting antenna is arranged inside an anechoic chamber, so as to transmit test signals that interfere with work of the key-free system to be tested inside the anechoic chamber, and a test signal band elimination filter is arranged in the anti-interference test system and used for filtering from the test signals those within a band elimination frequency band corresponding to the frequency of a working signal, so as to eliminate influence of the test signals on the key signal, thereby enabling a test result to be relatively accurate.

The invention relates to a radio frequency identification (RFID) dual-mode antenna for a high-frequency (HF) and ultrahigh-frequency (UHF) ticket checking system, which is mainly used for realizing the high-isolation design, perfect compatibility and no mutual impact of two types of different-frequency-band antennas. The radio frequency antenna comprises an HF closed-loop antenna and an UHF ceramic antenna array. The ceramic antenna array is controlled to switch by a micro control unit (MCU) through radio frequency switches, so as to enable antenna branches to be conducted by turns. On the premise that the magnetic induction lines of the HF antenna is not affected, the goal that the two types of different-frequency-band antennas work at the same time is realized. The RFID dual-mode antenna has the advantages that the problem in the electromagnetic compatibility of a UH radio frequency antenna can be solved, the evenness of ticket reading is guaranteed, the situation of misreading is precluded and the safety of ticket check is ensured.

The invention relates to an RS485 automatic transceiving control method and circuit. An inverting circuit transmits an inverted TX (transmit) signal to the reset (RST) end of a counting circuit and to the R end of a trigger; a clock generation circuit generates clock frequency fixed to a serial communication Baud rate, and transmits the clock frequency to the CLK (clock) end of the counting circuit; the output end of the counting circuit is connected with the S end of the trigger; and the output end of the trigger is connected with the enable end (DE) of RS485. When the TX signal changes from a higher level value to a lower level value, the circuit transmits a high-level enable signal to the DE port of the RS485 chip to start data transmission; when the TX signal changes from a lower level value to a higher level value, a timer starts and keeps the high-level enable signal of the DE port of the RS485 chip; and the circuit transmits a low-level transmission stop signal to the DE port of the RS485 chip to stop the data transmission if the high-level retention time of the TX signal exceeds the number of frame beats of serial communication information. According to the invention, the RS485 automatic transceiving method and circuit can save the port resources of CPU (central processing unit), and improve communication real-time performance, the interference resistance and the electromagnetic compatibility of the entire system communication.

The invention discloses a satellite navigation receiver electromagnetic compatibility test device based on orthogonal signal input and a test method and belongs to the electromagnetic compatibility test field. The test device comprises a host PC, various test signal sources, an orthogonal modulation and demodulation module, a posture adjustment module, an emission/reception antenna, a combiner, a power splitter and a frequency spectrum measurement device. The test method comprises steps of generating simulation navigation signals to make a receiver operate normally, generating reference signals and interference signals and adjusting intensity according requirements, measuring strength values of the incident reference signals in different directions, contrasting strength of different antenna reception signals, analyzing zero trapping property, correcting simulation navigation signals according to the zero trapping property, using the corrected signals for tests, and determining electromagnetic compatibility of the receiver. The test device and the method are advantaged in that the reference signals are utilized to test direction property of an adaptive antenna, the orthogonal modulation method is utilized to guarantee that the reception end can separate the reference signals, test authenticity and high precision are guaranteed, and engineering realization difficulty is reduced.

Systems and arrangements to provide electromagnetic compliance (EMC) for a drive carrier are disclosed. Embodiments may include an EMC spring. The EMC spring may include a shield portion to fasten to one side of a frame of the drive carrier and multiple fingers attached to the shield portion. At least one of the fingers may include an upper spring section to contact an adjoining drive carrier as the drive carrier is inserted into a computing device and a lower spring section. The lower spring section may be folded over against the upper spring section and attached to the shield portion of the spring. The lower spring section may deflect in response to the upper spring section contacting the adjoining drive carrier. In some embodiments, a lead in portion of the upper spring section may deflect to a position nearly parallel to the adjoining drive carrier.

The invention provides a nonmetal air cylinder for an electromagnetic compatibility test and an antenna device and system with the adjustable rotation angle. The antenna device with the adjustable rotation angle comprises a nonmetal air cylinder, a first connecting piece and an antenna, wherein the antenna is sleeved with a rotary sleeve and then loaded into a first installation hole of the connecting piece and at least one end of the antenna extends out of the first installation hole; the first connecting piece is further provided with a second installation hole, a first piston rod of the nonmetal air cylinder penetrates to an end cover of the nonmetal air cylinder and the second installation hole of the first connecting piece in sequence and then is contained in a groove of the first connecting piece; and the first piston rod of the nonmetal air cylinder is connected with the rotary sleeve to drive the antenna to rotate from 0 degree to 90 degrees. By the adoption of the technical scheme, the work principle is simple, operation is convenient, reliability is high, and antenna multi-dimensional space localization can be achieved by controlling the rotation angle of the antenna and adjusting the pitch angle of the antenna.