222results about How to "Solve electromagnetic interference" patented technology

The invention discloses an isolation type integrated AC-DC converter on the basis of bridgeless PFC (power factor correction) and LLC (logic link control) resonance. The isolation type integrated AC-DC converter is characterized by comprising a preceding-stage bridgeless totem-pole PFC circuit and a backward-stage half-bridge LLC resonance circuit; the preceding-stage bridgeless totem-pole PFC circuit is used for converting alternating-current input voltages into direct-current voltages; the backward-stage half-bridge LLC resonance circuit is connected with the preceding-stage bridgeless totem-pole PFC circuit in parallel; a primary side of the backward-stage half-bridge LLC resonance circuit is of a half-bridge circuit structure and is used for implementing zero-voltage flexible switching, and a secondary side of the backward-stage half-bridge LLC resonance circuit is of a full-bridge rectification structure and is used for rectifying alternating-current voltages into direct-current output voltages. The isolation type integrated AC-DC converter has the advantages that input currents can effectively change along with the input voltages, and accordingly the isolation type integratedAC-DC converter has a power factor correction function; the output voltages can be controlled by the isolation type integrated AC-DC converter, and accordingly the stable direct-current output voltages can be outputted.

The invention discloses a differential dual-band dual-polarized filtering antenna applied to a 5G Sub 6GHz base station system. The antenna comprises upper-layer and lower-layer dielectric substratesand four metal columns connecting the upper-layer and lower-layer dielectric substrates; the upper-layer dielectric substrate 1 is provided with a metal radiation patch, and a metal floor 2 is arranged on the upper surface of the lower-layer dielectric substrate and a metal feeder is printed on the lower surface of the same; the dual-band filtering property of the gain is acquired through slottingthe metal radiation patch and introducing a stepped impedance type open circuit branch knot into the metal feeder. The differential dual-band dual-polarized filtering antenna has the advantages of being simple in structure, easy to machine, relatively wide in resonant bandwidth within radiation band, relatively good in dual-band filter response, stable in gain and directional diagram, relativelylow in cross polarization, relatively high in port isolation, and easy to be integrated with the differential circuit. The differential dual-band dual-polarized filtering antenna can be applied to the5G Sub 6GHz base station communication system, and is particularly suitable for +/-45 degree dual-polarized base station antenna system of two bands: 3.3GHz-3.6GHz and 4.8GHz-5.0GHz.

The invention discloses a transmission line dynamic loss measurement system and a transmission line dynamic loss measurement method, which belong to the technical field of high-voltage transmission line detection. The transmission line dynamic loss measurement system is based on global positioning system (GPS) clock pulse synchronous triggering, and comprises voltage and current acquisition systems and industrial personal computer units which are arranged at substations at the two ends of a transmission line respectively. Voltage and current signals are extracted by utilizing a zero-flux current transformer, and are transmitted to a data acquisition card in an industrial personal computer by an optically powered data link (OPDL) photoelectric link system, the data acquisition card is triggered by using GPS clock pulses to realize the synchronism of voltage and current acquisition at the front and tail ends of the line, and the power of the two ends of the line is calculated by using an instantaneous power method to obtain the dynamic loss of the whole transmission line. The simultaneous acquisition of voltage and current at the two ends of the line is realized, a numerical value of the synchronization accuracy is less than 0.1 microsecond, high measurement accuracy and convenience of operation are ensured, the problem of insulation is solved, and potential safety hazards are avoided.

The power feeding equipment (PFE) includes a laser energy delivering power supply (LEDPS), a CT energy taking power supply (ETPS) connected to LEDPS in parallel, and a unit for monitoring and controlling working conditions of parallel circuit between LEDPS and ETPS. The function for monitoring and controlling the parallel circuit realizes automatic switching between LEDPS and ETPS based on actual working conditions. Being independent on working conditions of circuitry of high voltage / super voltage transmission, PFE can supply power for high voltage / super voltage transmission continuously. PFE also includes an energy storage unit in use for making smoothly and seamlessly switching between LEDPS and ETPS for load. Features of PFE are: long continuous service life, and lower cost.

A method for accurately solving wind turbine blade echoes is provided, in order to obtain accurate blade echoes. The method mainly comprises three parts: firstly, solving two-dimensional backscattering field data of wind turbine blades within a range of a certain frequency band and a certain corner angle; secondly, according to the obtained two-dimensional backscattering field data of the blades,calculating an autocorrelation covariance matrix, and solving electromagnetic scattering electric field amplitudes and space coordinate parameters of the blades; and thirdly, establishing a blade equivalent model according to the obtained electric field amplitudes and space coordinate parameters, and deriving an equivalent model-based blade echo expression, so as to solve the blade echoes. The method provided by the present invention can be used to accurately solve the blade echoes and to realize the blade echo filtering on the radar side in actual engineering, and has significance to solve the passive interference of the wind turbine to the adjacent radar station.

The invention discloses a low-interference food processing machine, comprising a control circuit. The control circuit comprises a load for food processing, a load circuit for driving the load to work and a control chip. The load circuit comprises a switch which is a thyristor. The control chip controls the thyristor in a wave leaking way. The control chip controls the thyristor with a trigger pulse. A rising edge of the trigger pulse is at a zero-crossing point of power supply voltage. The trigger pulse maintains at the point of a minimum rate of change of the power supply voltage. The control chip can remove the trigger pulse at the minimum rate of change of the power supply voltage by adjusting the maintaining time of the thyristor trigger pulse, the interference brought by the thyristor trigger can thus be reduced, and the problem of magnetic interference of the resistive load is solved.

The invention discloses a hydraulic actuator. The hydraulic actuator comprises a hydraulic cylinder assembly, a hydraulic system and a local closed-loop control system, wherein the hydraulic cylinder assembly comprises a single-action oil cylinder, a displacement sensor, an upper ear ring and a lower ear ring; the upper ear ring is in threaded connection with a piston; the displacement sensor is arranged on a lower end cover; a measuring rod of the displacement sensor passes through the lower end cover, and extends into the piston; a magnetic ring of the displacement sensor is arranged on the end part of the piston; the piston drives the magnetic ring to move in a way of extending and retracting; the specific position of the magnetic ring is sensed through a waveguide tube in the measuring rod, so that the absolute position of the piston is detected; the hydraulic system comprises a motor, a pump, two leakage-free reversing valves and a pressure sensor, and is used for providing hydraulic power for a hydraulic cylinder and controlling the flow; the closed-loop control system comprises a main circuit module, a power supply module, a sensor module group and a microprocessor module. The hydraulic actuator has the advantages of high positioning accuracy and low cost, accurate source changing, scanning, tracking and position keeping of the oil cylinder can be realized, and continuous and stable control of the actuator during low-speed running can be ensured.

The invention discloses a hospital environment monitoring system based on Internet of Things. A signal receiving circuit receives a signal in a data transmission channel of an Internet of Things hospital environment monitoring system; a 45Hz low-frequency signal resonant with the signal frequency in the data transmission channel is generated through a duplex filter circuit and a double-T frequencyselection circuit and transmitted to a signal intensifier circuit; amplitude adjustment is performed by using an impedance inverter circuit and an in-phase proportional amplifying circuit, and finally the signal is output through a holding circuit. By means of the on-off state of a gate circuit composed of a triode Q1, a resistor R11 and a resistor R13 and a diode D1 as well as a subtractor AR1,a feedback amplitude modulation circuit couples a difference signal to the input end of an operational amplifier AR2 through a resistor R6 or connects a resistor R5 and a resistor R6 in series in parallel to the equivalent resistance value, so that the linear stable signal amplitude can be transmitted to a terminal server of the monitoring system more effectively after gain amplification. The system solves the problems of signal distortion and incapability of conducting effective monitoring caused by the interference of an electronic device or electromagnetic interference between the numeroussignals and attenuation.

The invention discloses a confirming method of same frequency multiple interference for an electromagnetic coupling weak path, and belongs to the technical field of electromagnetic compatibility. Electromagnetic coupling relations of a plurality of interference sources and a plurality of sensitive points in a system are translated into digraphs, and sides of the coupling digraphs are valued through simulation and testing; then coupling paths where interference can be most easily generated between each interference source and each sensitive body are found from an electromagnetic coupling network in the same valued coupling digraph through a shortest-path tracking method for a plurality of times; and finally the same interference coupling path is extracted form a weak path from the each interference source to the each sensitive body, key rectification is conducted aiming at the weak path of repeated coupling, and therefore maintenance and strengthening of system electromagnetic compatibility faults are efficiently and accurately achieved, and electromagnetic compatibility problems can be accurately and effectively solved with low cost.

The invention relates to patulous multiple tyres TPMS system that comprises emitter, antenna, main controller, and code card cage, code module, when said main controller is started or repositioned, reading ID code of all code module, and storing corresponding relationship between the ID code and tyre identity; sensor of said emitter converts the change of tyre pressure and temperature to corresponding changeable electric parameters via electronic element, and emitted by the emitting circuit after process; wireless signal is received by antenna, and decode by modulation and demodulation circuit, then data is transferred to main controller CPU via the SPI bus, the CPU saves data to corresponding area according to corresponding relationship of tyre identification, and displays data in corresponding data area. Comparing with current technique, the invention possesses characters that the performance is stable, and it is easy to be realized, and convenient to be expanded.

The invention discloses a multi-frequency equalization carrier slope random distribution pulse width modulation method to increase the equivalent bandwidth of symmetrically distributed harmonics centered on multiple carrier frequencies to realize the increase of the uniform distribution of the harmonics in a frequency domain. The method comprises steps of (1) selecting a required random carrier sequence and a modulated wave and comparing the two to generate a switching device driving signal for pulse width modulation; (2) determining a multiple n of an equivalent carrier frequency f of the random carrier sequence and selecting a main circuit topology; and (3) inputting the switching device driving signal generated in the step (1) to the main circuit topology in the step (2) and performingmulti-frequency equalization carrier slope random distribution pulse width modulation. The method of the invention can greatly improve the frequency domain distribution bandwidth of the harmonics without changing the mean and variance of the random carrier sequence, and realize the more uniform distribution of a plurality of harmonic peaks near the carrier and the multiplier thereof in a wider frequency domain.

The invention discloses a new energy power station dynamic reactive power compensation equipment application method. The improved content is as follows: (1) the dynamic reactive power compensation equipment is connected onto a low voltage-side bus of a three-winding boost transformer, the middle voltage side of the three-winding boost transformer is connected with gathered new energy electric power, and the two are isolated via the transformer; (2) voltage at the high voltage side of the new energy power station serves as reactive power needed by a calculation system for calculating reference voltage and control target voltage; and (3) a novel electronic current voltage combined transformer is applied to a measurement control system for the dynamic reactive power compensation equipment. In view of problems of poor operation stability of the new energy power station and disqualified electric power quality, a dynamic reactive power compensation configuration technology which can be applied to grid-connected power generation of the new energy power station and meet grid requirements is brought forward, a dynamic reactive power compensation equipment mounting site is changed, the new energy collecting system and the reactive power compensation equipment can be effectively isolated, the problems of operation stability of the new energy power station compensation equipment and electric power quality can be solved, and operation stability of the reactive power compensation equipment is improved.

The invention discloses a self-adaptive type LED driving circuit. The self-adaptive type LED driving circuit comprises a fluctuation direct-current power source, a current control circuit and a current limiting or constant current circuit, wherein the fluctuation direct-current power source is used for generating direct-voltage signals with periodically-changed voltages, the current control circuit is used for changing the series-connection and parallel-connection relationship between LED strings to adapt to the periodical changes in the direct-voltage signals by themselves, and the current limiting or constant current circuit is used for carrying out current limiting on the direct-voltage signals or keeping the constant current of the direct-voltage signals to drive the current control circuit to run. The fluctuation direct-current power source, the current control circuit and the current limiting or constant current circuit are connected in series to form a closed loop. The current control circuit at least comprises two current control sub-units, each current control sub-unit comprises a first normally-closed switch, a second normally-closed switch, a fourth normally-closed switch, a first diode and a second diode. According to the self-adaptive type LED driving circuit, the LED strings can be connected in parallel or in series through the normally-closed switches according to the input voltage and the circuit current, the total voltage of the LED strings can be accordingly changed, and the LED strings can automatically adapt to changes in the input voltage.

The invention discloses a split networked intelligent temperature controller of a central air conditioner. The temperature controller comprises a control panel and a power supply board which are connected; the control panel comprises a temperature measurement module, a liquid crystal display module and a parameter setting module; and the power supply board comprises a power supply module, a relaycontrol module and an RS485 interface circuit, wherein the power supply module supplies power to the relay control module and the control panel. A single micro control unit (MCU) structure is adoptedin the temperature controller, and the front panel and the rear panel are split in the design; and by adopting the single MCU, the defect that a wiring tube of the traditional temperature controller is not easily connected to centralized (remote) monitoring of the central air conditioner is overcome, the dependency of civil engineering is reduced, the use safety is promoted, the universal applicability of any standard junction box is enhanced, and the networked expansibility of the system is exploited.

The invention provides a design and manufacturing method of light guide points on a light guide plate. The design and manufacturing method includes 1, designing distributing position and size of a point of the light guide points, and controlling size of the point through laser lighting time or by controlling power of laser; meanwhile, dividing all the light guide points into several light guide point lines; 2, dividing point image into several areas, processing the light guide points among each area and inside the areas randomly during the process; or processing one by one the light guide points in odd number lines among the light guide point lines; after all the light guide points in the odd number lines are processed, processing one by one the light guide points in even number lines among the light guide point lines along the vertical direction until all the light guide points are processed. With the design and manufacturing method, possible influence on results such as electromagnetic interference and equipment temperature flutter and drift during pointing process is overcome, influence on light guide point processing from external factors can be minimized, and uniformity of the processed light guide plate is good.

The invention provides an antenna device and a mobile terminal. The antenna device comprises a first antenna assembly, a second antenna assembly, a first inductor and a second inductor, wherein the first antenna assembly is connected with a motherboard via a first feed point; the second antenna assembly is connected with the motherboard via a second feed point; the first end of the second antenna assembly is adjacent to the first end of the first antenna assembly; the first end of the first inductor is grounded, and the second end of the first inductor is connected with the first end of the first antenna assembly; and the first end of the second inductor is grounded, and the second end of the second inductor is connected with the first end of the second antenna assembly. According to the embodiment of the invention, the isolation degree between antennas can be improved, and mutual interference between systems can be reduced.

The invention discloses a photoacoustic endoscope for high-precision three-dimensional scanning of a front micro motor and an imaging method. The endoscope comprises a probe shell, an optical reflecting prism, a micro motor, an ultrasonic transducer and an optical varifocus lens; the probe shell is provided with a micro motor placement cavity, an oil chamber and a containing cavity; the ultrasonictransducer is arranged in the middle of the probe to separate the oil chamber from the containing cavity; the optical varifocus lens is arranged at the end, close to the ultrasonic transducer, in theprobe containing cavity, the main part of the micro motor is fixed to a micro motor placement cavity in the top end in the probe, and a central metal shaft of the micro motor can move back and forthwhile rotating. The photoacoustic endoscope for the high-precision three-dimensional scanning of the front micro motor and the imaging method have the advantages that the scheme of only rotating and moving the reflecting prism and not rotating or moving other components is provided for photoacoustic endoscope three-dimensional imaging, thereby solving the problems of electromagnetic interference,precision and the like which are caused by a larger rotating motor and stepping motor; the scanning efficiency and precision are high, the range of single scanning is large, and multi-parameter physical information and multi-scale structure imaging of cavity tissue can be obtained.

The invention discloses a two-degree-of-freedom motion platform based on piezoelectric ultrasonic vibrator driving, relates to the technical field of multi-degree-of-freedom motion platforms, and aims to solve the problems of complex structure, electromagnetic interference and self-locking complexity of an existing electromagnetic motor driven motion platform. Two rotational degree-of-freedom platforms are directly driven by the aid of a piezoelectric ultrasonic vibrator, the two-degree-of-freedom motion platform has the outstanding advantages that the motion platform is simple in structure, low in cost, light in weight, self-locking in power failure, quite simple and convenient to machine and assemble and high in safety, energy consumption and electromagnetic interference are avoided, and serialization is easily realized. The two-degree-of-freedom motion platform is applicable to the technical field of the multi-degree-of-freedom motion platforms.

The invention provides a router comprising a lower shell, a PCB, an upper shell and a radiating part, wherein a mounting base, a plurality of sleeve columns provided with springs in a sleeved mode, and a plurality of limiting parts located at the edge of the lower shell are arranged on the lower shell; the PCB is installed on the mounting base, and the portions, on the periphery of the PCB, of the sleeve columns are arranged on the lower shell; the upper shell comprises abutting press parts arranged corresponding to the sleeve columns, and buckling connection parts arranged corresponding to the limiting parts; the abutting press parts abut against the free ends of the springs, and the buckling connection parts are movably connected with the limiting parts in a buckling mode; the radiating part is electrically connected to the PCB through a signal transmission wire. A traditional shape of the router is changed through the structural design, the electromagnetic interference problem between the radiating unit, namely, an antenna, and the PCB is solved, the antenna is conveniently built in the router, meanwhile, the router is attractive in appearance, due to the unique design of the antenna, electromagnetic signal receiving and transmitting capacity of the router is improved, and requirements of wireless communication can be well met.

The invention discloses a semiconductor device. The semiconductor device comprises a package substrate including a bonding area used for connecting bonding wires; and at least one die provided on the package substrate. Each die comprises a wafer substrate and a pin disposed on the wafer substrate. Each pin is used for connecting the bonding wire. The thickness of each wafer substrate is between 50um to 400um. By thinning the wafer and reducing the thicknesses of the dies, the semiconductor device can reduce the average height of the bonding wires from a ground plane, thereby improving the electrical isolation between the bonding wires and between the bonding wires and other sensitive components, lowering mutual inductance, solving the problem of electromagnetic interference and improving chip performance.

The present invention discloses a triangular carrier slope random distribution pulse width modulation circuit. The circuit comprises a system clock module, a counter module, a Rom module and a random triangular carrier processing module. The system clock module is configured for system clock signals; the counter module is configured to output the count according to the real-time system clock signals; the Rom module is configured to take the count as an address, take out stored random data [Delta]i and transmit the random data [Delta]I to the random triangular carrier processing module; and the random triangular carrier processing module is configured to generate the random triangular carrier according to the random data [Delta]I and output the random triangular carrier to a modulation main circuit. The triangular carrier slope random distribution pulse width modulation circuit can reduce the electromagnetic interference in an electric system from the source and reduce the mechanical vibration and the noise in the condition that the pulse width modulation main circuit topology is not changed so as to provide a new way for effectively solve the electromagnetic interference problem in the electric system and the vibration noise problem at the external portion of the system; and moreover, the vibration and noise reduction does not rely on an additional device so as to reduce the filtering and vibration cost and save the system resource.

The invention discloses a ZIGBEE based LED street lamp illumination monitoring system which comprises a monitoring center, a ZigBee coordinator, a ZigBee router, a monitoring terminal, an alternating current input module and a direct current voltage-stabilizing power supply module. The monitoring terminal comprises, at least a power control module, an LED driving module and an LED abnormity warning detection module. The problems which also exist in the traditional control of a network formed by combining a ZigBee technology and a sensor technology are solved, the brightness intensity can be acquired in real time, the mistaken switching-on and switching-off possibilities in a special environment in a special period of time are greatly reduced, and manual intervention is omitted.