64results about How to "Meet electromagnetic compatibility requirements" patented technology

The invention discloses a low-smoke halogen-free light intrinsically-safe instrument flexible cable for ocean engineering, which belongs to the field of cables. The low-smoke halogen-free light intrinsically-safe instrument flexible cable comprises a cable core, wherein the cable core is formed by four rectangularly distributed unit cables and a filling material on the periphery of the unit cables which are twisted together; each unit cable comprises a core conductor with an insulating layer, a unit shielding layer, a unit wrapping layer and an internal current introducing wire; the unit shielding layer is wrapped outside the pair-twist core conductor with an insulating layer, an internal current introducing wire is arranged on the inner side of the unit shielding layer, and the unit wrapping layer is wrapped outside the unit shielding layer; and an internal wrapping layer is arranged outside the cable core, an integral shielding layer wrapped by an aluminum-foil polyester compound band is arranged outside the internal wrapping layer, the inner side of the integral shielding layer is provided with an external current introducing wire, an external wrapping layer is arranged outside the integral shielding layer, an internal protective sheath is arranged outside the external wrapping layer, an armored layer knitted by tinned wires is arranged outside the internal protective sheath, and an external protective sheath is arranged outside the armored layer. The cable has the advantages of compact structure, convenient laying, small occupation space and superior overall performance, and can be safely used in ocean engineering.

An electric automobile energy storage mobile charging pile and system comprise a charging pile body, and further comprises a battery module located on the charging pile body, a BMS circuit set, an inverter circuit, a charging metering module, a wireless data module, a positioning module and a main control management module; the battery module is provided with a plurality of battery packs which areconnected in parallel; the BMS circuit set comprises a plurality of BMS circuits which are connected in parallel and are connected with the plurality of battery packs in a one-to-one correspondence mode; the inverter circuit is connected with the battery module to be converted to generate a slow charging voltage current or a fast charging voltage current; the charging metering module is connectedwith the inverter circuit; the wireless data module is connected with the main control management module to send related information or receive control information; the positioning module is connected with the main control management module to provide position information; and the main control management module is connected with the battery module and the charging metering module. According to the invention, a special charging parking space is not needed, and energy storage and charging can be carried out by utilizing the valley-hour electricity price, the problem of power grid capacity is solved, the charging economical efficiency, the power grid balance are facilitated, and the charging cost is low.

The invention relates to a modularized mixed filter connector which comprises a plug and a socket. The mixed filter connector is characterized in that: the plug and socket of the connector are both provided with modules with radio frequency and wave filtering functions. The plug and a socket casing of the connector are both provided with chambers the number of which corresponds to the number of the modules with the functions. Every functional module is fixedly arranged in the corresponding chamber. The connector can transmit different signals simultaneously through different modules, has strong anti-interference performance, and meets the development trend of the requirements of equipment to electromagnetic compatibility. Besides, the connector is detachable, has the advantages of convenient assembly and maintenance and can meet the requirement of site replacement.

The invention discloses an installing structure and an installing method for a touch screen and a liquid crystal screen of a train vehicle-mounted display. The installing structure comprises the touch screen, the liquid crystal screen, a display screen front case, a screen installing assembly, a liquid crystal screen rubber pad and a touch screen rubber pad, wherein the screen installing assembly is fixedly arranged at two sides of the liquid crystal screen, the liquid crystal screen rubber pad is pasted at the periphery of the front side of the liquid crystal screen, the touch screen is pasted on the crystal screen rubber pad, and the screen installing assembly is fixedly connected with the display screen front case. The installing method comprises the steps that the screen installing assembly is sheathed at two sides of the liquid crystal screen, the liquid crystal screen rubber pad is pasted at the periphery of the front side of the liquid crystal screen, and the touch screen is pasted on the liquid crystal screen rubber pad; the liquid crystal screen rubber pad is pasted at the inner side of the display screen front case, the edge of the touch screen is in full contact with the liquid crystal screen rubber pad, and finally, the screen installing assembly is fixedly connected with the display screen front case. The installing structure and the installing method have the advantages that the operation is simple, the positioning is accurate, stable and firm, the response accuracy of the touch screen is improved, the casing insulation performance is improved, and the electromagnetic compatibility requirement is met.

The invention relates to a three-body frame type controller which belongs to the electronic control technique field. The controller is composed of a middle frame, an upper cover and a down cover. A concave-convex inlay structure is used between the middle frame and the upper/down covers, a convex edge is set around upper and down periphery of the middle frame, a concave groove matched with the convex edge is set on the upper cover and the down cover, an electric conducting rubber sealing ring is set in an end face of the upper/down cover and the middle frame, four convex ears are set on the middle frame outside for installing an vibration isolator; a convex ring belt is set on three faces of the middle frame middle, two socle beams are set on the fourth face, a circuit board is supported on upper side and down side of the ring belt and the socle beam, an European style insert is used in middle of two circuit boards for processing electric connecting, a Chinese character 'ri' pattern frame is pressed connected firmly on the circuit board. The controller has advantages of better resistance to shock, assemble manufacturability, heat transfer property, seal performance and reliability, and has beautiful appearance.

The invention relates to a method for realizing the insulation coordination of basic functional units of a voltage source converter (VSC) based on a half bridge circuit, which comprises the following steps of: 1) determining the insulation strength and properties of each component according to the steady-state over-voltage level, transient-state over-voltage level and transient over-voltage level of a sub-module under various operation conditions; 2) making equal the ground potential of a metal shell and a secondary control protection board of primary equipment and the potential of the cathode of the sub-module according to the potential distribution characteristics of the sub-module, and connecting the secondary control protection board and a primary circuit by using an isolation transformer to isolate the influence of the high voltage of the primary circuit on a secondary circuit; 3) shielding the electromagnetic interference of an insulated gate bipolar translator (IGBT) high speed switch in the secondary control protection board by using a metal shielding box according to the electromagnetic field distribution of the sub-module; 4) making equipotential an operating mechanism of a bypass switch and the cathode of the sub-module; and 5) selecting a high voltage wire as a wire crossing a high potential and a low potential to reduce the local discharge capacity of the sub-module. By the insulation coordination method, the insulation requirements of a system can be met, and high security and high economy are achieved.

The embodiment of the invention provides a wireless network power control method and system based on the Internet of Things. An STA receives power control information broadcasted by the AP in the IoT channel, and the power control information is broadcasted and sent by the AP in the IoT channel according to the configuration of the network management module; and the STA adjusts the wireless signal transmitting power according to the power control information and a preset power control decision. When the STA moves between different power level areas, the STA can be switched to different power level areas. The STA receives power control information broadcasted by APs located in different power level areas in the IoT channel, therefore, the STA can judge whether the STA is located at the center position or the edge position of the power level area according to the received power control information; the wireless signal transmitting power is adjusted before the wireless signal transmitting power is accessed to the AP of a certain power level area, electromagnetic interference to equipment in the power level area is avoided, the requirement for electromagnetic compatibility of the equipment is met, and the operation stability of the equipment is guaranteed.

The invention discloses a fluid circuit circulating pump driver, which relates to the field of aerospace engineering. The actuator is adapted to drive the fluid loop circulating pump motor, comprisesa digital-to-analog conversion module, an analog control module and a drive module connected in turn, the drive module is connected with the circulating pump motor, wherein the digital-to-analog conversion module is used for acquiring a digital control signal for controlling the rotational speed of the circulating pump motor, The digital control signal is converted into the analog control signal.The analog control module is used for pulse width modulation of the analog control signal to generate a driving signal. The driving module is used for power amplification of the driving signal and sent to the circulating pump motor. The driver provided by the invention does not contain a high-cost microprocessor immune to the space environment, adopts a pure analog circuit control mode inside thedriver, has wide speed regulating range and high rotational speed stability, has strong simple anti-interference ability of an external digital control interface circuit, and meets the electromagneticcompatibility requirements.

The invention discloses a method for allowing a laptop interface to achieve electromagnetic compatibility and to be prevented from getting wet in rain. A silicone rubber door is processed through the wire mesh and conductive coating dual-layer shielding method, the surface of a silicone rubber material is coated with a conductive coating in a spray mode, a wire mesh layer is embedded in the silicone rubber material, a piece of wire mesh extends to the surface layer of the silicone rubber door, and the wire mesh and conductive coating dual-layer shielding is achieved; shielding layers and a machine shell are pressed tightly through the elasticity of silicone rubber; the conductive coating makes contact with the periphery of the machine shell after the silicone rubber door is closed, and the first layer of shielding is formed; the wire mesh makes contact with the machine shell under the preload of the silicone rubber door, and the second layer of shielding is formed. By means of the technology, while the elasticity of the silicone rubber material is fully utilized to achieve interface sealing, the requirement for electromagnetic compatibility of the military laptop interface can be met; due to the elasticity of the silicone rubber material, the requirements for rain prevention and sealing are met.

The invention provides a twelve-phase permanent magnet propulsion converter. The twelve-phase permanent magnet propulsion converter is characterized by comprising twelve same standard inverter modules, twelve same filters and two same standard brake modules, wherein the twelve standard inverter modules and the two standard brake modules are evenly distributed in two channels; three-phase AC is input through a rectifier transformer and an equilibrium reactor and DC voltage is output to common DC busbars in the two channels respectively; the standard inverter modules and the standard brake module in each channel are connected to the corresponding common DC busbar in parallel; an output end of each standard inverter module is correspondingly connected to an input end of one filter; and the output end of each filter is correspondingly connected to one phase of start winding of a motor. The 1.8MW/twelve-phase permanent magnet propulsion converter provided by the invention is high in integrated modularization degree, low in noise, good in reliability and good in maintainability, and is used for directly driving low-noise operation of a permanent magnet propulsion motor of a ship.

An electrical connector has an insulative body, a plurality of conductive terminals and a shielding shell. The shell is formed by first and second shielding pieces. The first piece has an annular structure provided at the front and a first semi-enclosing structure provided at the rear. The annular structure has an insertion port. The port has a front portion of a mating cavity of the connector. Two sides of the first structure each are formed with a first joint portion. The second piece has a second semi-enclosing structure. Two sides of the second piece each are formed with a second joint portion which is correspondingly fixed to and engaged with the first joint portion. The second structure and the first structure face each other in an up-down direction and are engaged with each other to enclose a tongue so as to form a rear portion of the mating cavity.

The invention relates to the technical field of ship devices, and discloses handrail rigging used for ships. The handrail rigging used for the ships comprises a steel wire rope. The two ends of the steel wire rope are connected with end portion connection pieces correspondingly. The handrail rigging used for the ships further comprises a first connection piece and a second connection piece. The first connection piece and the second connection piece are used for being connected with handrail columns correspondingly. The first connection piece is connected with the end portion connection piece at one end of the steel wire rope through an insulating piece. The second connection piece is connected with the end portion connection piece at the other end of the steel wire rope through an insulating piece. The end portion connection pieces are arranged at the two ends of the steel wire rope of the handrail rigging used for the ships correspondingly, the first connection piece and the second connection piece are connected with the end portion connection pieces through the insulating pieces correspondingly. When the ships work in areas with disordered electromagnetic fields, electric currentis blocked by the insulating pieces and cannot be transmitted to the handrail columns or ship bodies, insulation between the handrail rigging and the ship bodies is achieved, and the requirement of the military ships for electromagnetic compatibility is met.

The invention provides a method for achieving electromagnetic compatibility of a tablet computer with a plastic shell. The shell of the reinforced tablet computer comprises a lower cover and an upper cover which are manufactured through injection molding. Six screw through holes are formed in the periphery of the upper cover, and the periphery of the lower cover is correspondingly provided with six screw holes. The upper cover and the lower cover are fastened together through self-tapping screws. In order to allow the plastic shell of the reinforced tablet computer to be conductive, and the surface of the shell, the inner surface of the lower cover, the contact edges of the upper cover and the lower cover, the outer surface of the lower cover, the inner surface of the upper cover, the contact edges and grooves of the upper cover and the lower cover and the outer surface of the upper cover are electroplated. The method has the advantages that the shell of the reinforced tablet computer is made of plastics, overall weight of the tablet computer is reduced effectively, the surface of the plastic shell is plated, the gap between the lower cover and the upper cover after the two are assembled is sealed, touch screen positions with large electromagnetism leakage is shielded, and the reinforced tablet computer with the plastic shell can satisfy the electromagnetic compatibility requirements of national military standard.

The invention discloses a permanent magnet direct current motor with a capacitor delta connection structure meeting EMC requirements, and belongs to the technical field of permanent magnet direct current motors. The rotor assembly of the permanent magnet DC motor includes the motor shaft and the oil baffle plate, commutator, varistor, PCB board, iron core, copper sleeve and gasket arranged on it in sequence. The rotor coil of the rotor assembly is wound on the rotor iron Between the core slots; the PCB board is provided with several chip capacitors, and the chip capacitors are connected to the commutator through the PCB board; the several chip capacitors are connected on the PCB board through a "△" type connection circuit , the piezoresistor is placed on the upper layer of the PCB and welded to the commutator pin. The permanent magnet DC motor of the present invention replaces the traditional structural design of placing electrolytic capacitors in the rotor coil gap by introducing a PCB board with patch capacitors, so as to achieve higher EMC effects and reduce processing and manufacturing costs.

The embodiment of the invention discloses an intelligent trailing edge dimming device based on an MOSFET. The intelligent trailing edge dimming device comprises an MOSFET basic chopper circuit, an MOSFET driving and short-circuit protection circuit, an MOSFET driving power-taking circuit, an MOSFET anti-high-voltage pulse protection circuit and an EMI interference elimination circuit. The MOSFET basic chopper circuit is connected with the MOSFET driving and short-circuit protection circuit, the EMI interference elimination circuit and the MOSFET high-voltage pulse resistance protection circuit; the EMI interference elimination circuit is connected with the MOSFET anti-high-voltage pulse protection circuit; the MOSFET anti-high-voltage pulse protection circuit is connected with a driving load; the MOSFET driving and short-circuit protection circuit is connected with the MOSFET driving power-taking circuit; and the MOSFET driving power-taking circuit is connected with a driving load. Through the above technical means, a plurality of semiconductor devices form the intelligent trailing edge dimming device, miniaturization of equipment is achieved, EMC electromagnetic compatibility requirements are met, pure resistive loads and capacitive loads are compatible, and most market requirements can be met. A plurality of protection circuits are configured, so that the stability of the MOSFET basic chopper circuit is improved, and the reliability of the intelligent trailing edge dimming device is improved.

The invention discloses a main power supply and standby power supply switching circuit, which comprises a direct-current input main power supply U1 and a direct-current input standby power supply U2 for supplying power to a ship rectification generator, a first Boost chopper circuit for boosting the direct-current input main power supply U1, a second Boost chopper circuit for boosting the direct-current input standby power supply U2, counter-current protection diodes D1-D4, a filtering module and an inversion unit for converting direct-current input into three-phase alternating-current output,wherein the two Boost chopper circuits adopt closed-loop PID control, and the Boost branch output voltage U1' of the first Boost chopper circuit is controlled to be 2-10 V larger than the Boost branch output voltage U2' of the second Boost chopper circuit. According to the main power supply and standby power supply switching circuit, priority selection of main power supply branches and automaticswitching between main and standby power supplies can be realized; and compared with the traditional power supply switching circuit adopting a circuit breaker and a relay, the main power supply and standby power supply switching of the invention adopts a power electronic device to switch, has the extremely short switching time of only [mu]s, can ensure the uninterrupted output of the inverter sidein the power supply switching process, and achieves seamless switching.

The invention discloses a pre-branched cable which is characterized by comprising a trunk cable, branch cables and a connecting joint. The trunk cable and the branch cables are the same in structure and each comprise a cable conductor, a cable insulating layer, a cable shielding layer and a cable sheath layer. The cross-sectional area of the cable conductor of each branch cable is smaller than that of the cable conductor of the trunk cable. The connecting joint comprises a conductor connecting fitting, a fitting insulating layer, a fitting shielding layer and a fitting sheath layer. The numberof the branch cables is two or three, and each branch cable is fixedly and electrically connected with the trunk cable through the connecting joint. The fitting insulating layer of the connecting joint is connected with the cable insulating layer of each cable into a whole. The fitting shielding layer of the connecting joint is overlapped with the cable shielding layer of each cable in a coveringmanner. The fitting sheath layer of the connecting joint is connected with the cable sheath layer of each cable into a whole.

The invention provides a novel frequency modulation method and device using AC feedforward to improve EMI. AC feedforward is used. The switching frequency completes a frequency jitter from the zero-crossing point to the peak point of AC voltage in a cycle. The frequency is periodically changed. The frequency at the zero-crossing point of AC voltage is the lowest. The frequency at the peak point ofAC voltage is the highest. The frequency distribution is changed, so that the energy of several or dozens of frequencies with relatively high amplitude is dispersed to new components. According to the invention, the frequency is periodically changed according to the set method; the higher the number of harmonics, the greater the frequency dispersion; the noise harmonic frequency is dispersed, sothat the superimposed energy of harmonics at the switching frequency is reduced; the noise energy is dispersed and reduced; the amplitude margin is guaranteed over the entire frequency band; and the electromagnetic compatibility requirement is met.

The invention relates to the technical field of microelectronic heat dissipation, and discloses a double-sided efficient heat dissipation airtight packaging structure and a preparation method thereof. The packaging structure comprises a heat dissipation micro-channel, a packaging substrate, a first chip, a second chip, an enclosure frame, cover plates, a liquid cooling connector and an electric connector; the heat dissipation micro-channel and the enclosure frame are welded on the packaging substrate; the first chip is welded on the heat dissipation micro-channel, the second chip is welded on the packaging substrate, and the first chip and the second chip are interconnected with the packaging substrate; the cover plates are respectively welded on the enclosure frame and the packaging substrate; and the liquid cooling connector and the electric connector are welded at the bottom of the packaging substrate. According to the invention, efficient heat dissipation of the high-power chip and effective heat dissipation of the medium-and-small-power chip can be realized, so that heat in the packaging structure is uniformly distributed.

The invention provides a photomask for a laser radar, a preparation method of the photomask and the laser radar, the laser radar comprises a photomask fixing part, the photomask is installed on the photomask fixing part, and the photomask comprises a body which is provided with an inner surface and an outer surface opposite to the inner surface; and the first light-transmitting conductive film is arranged on the body and covers the inner surface or the outer surface, and the first light-transmitting conductive film is connected and conducted with the photomask fixing part, so that the laser radar can shield electromagnetic interference. According to the photomask designed by the invention, the electromagnetic interference shielding capability of the laser radar can be greatly enhanced, and the electromagnetic radiation of the laser radar to the outside is reduced, so that the laser radar has electromagnetic compatibility, and the requirement of vehicle-gauge-level electromagnetic compatibility is met.

The invention relates to an electronic rectifier, comprising a shell and an electronic circuit arranged in the shell; wherein the electronic circuit comprises a bridge type rectifier circuit and a starting circuit which is in serial connection with a high frequency contravariant circuit and a starter circuit, an abnormal protection automatic restoration circuit is bridge-jointed between the starting circuit and the high frequency contravariant circuit; the invention is characterized in that a power factor main rectifying circuit with power feedback is connected between the bridge type rectifier circuit and the starting circuit, and a power factor assistant rectifying circuit is arranged between the commercial electricity input end and the bridge type rectifier circuit. The invention has the advantages of effectively enhancing the lumen factor, increasing light output, inhibiting surging and avoiding damage caused by thunderstrike and super high power input; effectively reducing the adverse effect of super high temperature of a transistor caused by the situation that a triode can not fast enter saturate state and withdraw saturate state due to the aberration of wave shape during ascending and descending.

The embodiment of the invention provides a method and device for adjusting conducted emission of a switch mode power supply. The switch mode power supply comprises a power factor correction (PFC) circuit, a bus capacitor, a DC-DC conversion circuit and a control circuit. According to the method, a ripple voltage can be superimposed on the voltage of the bus capacitor when the input voltage of the switch mode power supply is DC voltage. According to the embodiment of the invention, the ripper voltage can be superimposed on the voltage of the bus capacitor, and thus, the electromagnetic compatibility requirement of a device in a power grid environment can be met when the switch mode power supply inputs the DC voltage.