93results about How to "Optimize thermal design" patented technology

The invention relates to a power module of wide input voltage scope which comprises a first and a second power input terminals, a rectifying filtrating circuit, a converting circuit which is connected between the first and the second power input ends and the rectifying filtrating circuit, the converting circuit is connected with the first and the second power input ends by the rectifying circuit, and the converting circuit comprises a first converter and a second converter; under the working mode of low voltage, the first converter and the second converter output in parallel connection; under the working mode of high voltage, and the first converter and the second converter output in series. Applying the power module of wide input voltage scope of the invention can realize high voltage input, the input voltage of the single converter is half of the input voltage, and the problem of voltage limitation of power devices is solved. When voltage is low, parallel connection is in favor of selecting other power tubes with smaller current. The wastage of power devices is distributed, thus being in favor of heat design. In the wide voltage scope, the utilization rate of the input DC filtrating capacitor is improved greatly. To alter the voltage scope, simple allocation is only carried out before use.

A light emitting diode (LED) light engine includes a solid transparent dome mounted on one or more LED dies to form a base module, a flexible sheath having embedded therein a phosphor that converts light of a first wavelength range to light of a second wavelength range, the sheath being attached to the base module so that the sheath conforms to a light emitting surface of the dome. The sheath emits light of the second wavelength range when the LED is emitting light of the first wavelength range. Further sheaths may be formed each with different phosphors or phosphor blends, and one of the sheaths may be selected to cover the base module depending on the color of light to be produced by the light engine.

The invention discloses a method for balancing capacitor voltage of a modularization multilevel converter. The method comprises the following steps: (1) the present value of submodule capacitor voltage is sampled to obtain increment of capacitor voltage in a power frequency period; (2) the increment of the capacitor voltage and the present value of submodule capacitor voltage are ranked; (3) a new corresponding relation between a drive signal and a submodule is obtained; (4) the drive signal is allocated to the submodule again according to the new corresponding relation. According to the method, the requirement for real-time performance is lower, and the computing resource of controllers is saved, so that the controllers can be used for processing a large-scale MMC system; no bridge arm current needs to be detected, so that the communication complexity among the controllers is simplified, part of the cost of a current sensor is saved, an additional hardware circuit is not needed to be added, and additional system cost is avoided; under the control of the method, all switch frequencies of the submodule are the same, the switch frequency is lower, the switch stresses are consistent and the system thermal design is facilitated and the system reliability is realized.

The invention discloses a 36-pulse high-power frequency conversion rectifier transformer, comprising triphase input primary winding which is mounted on a bracket and adopts Y-shaped connection and a phase shifting secondary winding adopting epitaxy triangle connection, wherein, the secondary winding comprises three groups, each of group comprises 6 phase shifting groups, the phase shifting angles are respectively +25 degrees, +15 degrees, +5 degrees, -5 degrees, -15 degrees and -25 degrees, each phase shifting group angle difference is 10 degrees; each phase is formed by series connection of a plurality of power units, adjacent groups of the triphase secondary output differ 10 degrees, the 6 phase shifting groups obtain 18 positive pulses and 18 negative pulses by controlling and triggering silicon controlled IGBT by different timing sequent of triphase pulses; the each phase shifting group has 3 taps, and each group has 18 taps in all which are connected correspondingly and arranged on the output wire ranging of one side of the bracket, and three groups of output wire ranging are used for connecting the transducer; the invention can reach less than 5% of network side current harmonics relief and has compact structure, small volume, simple installation, small field wiring and convenient debugging.

The invention relates to an LED (Light-emitting Diode) screen display unit which comprises an LED circuit board, and a power supply and a control panel, wherein the front face of the LED circuit board is equipped with an LED lamp while the back face of the LED circuit board is equipped with an electronic element, and power supply and signal combination hubs; the power supply and control panel is connected with the combination hubs; the LED screen display unit further comprises an insulated heat-conducting layer which is orderly adhered to back face of the LED circuit board and has a peripheral outline adapted to the LED circuit board, and an aluminum base; the aluminum base is internally provided with through holes for containing the combination hubs; one face of the aluminum base, which is close to the LED circuit board, is provided with a groove position for containing the electronic device; the insulated heat-conducting layer is provided with openings for the combination hubs to penetrate through; and the power supply and control panel is arranged at the back face of the aluminum base. The invention further relates to an LED display screen assembled by the LED screen display units. The LED screen display unit has the advantages of improving the radiation design, prolonging the service life and reducing the transportation and maintenance cost and is applied to the field of the LED display screen.

The invention relates to a chained active power filter differentiation control method. A cascade chain link unit is divided into a low-frequency module and a high-frequency module, the low-frequency module is used for generating a fundamental wave voltage required to be output by a chained multi-level inverter, and the high-frequency module is used for generating a voltage, without the fundamental wave voltage output by the low-frequency module, required to be output by the chained multi-level inverter. According to a period recycle mode, a plurality of chain link unit bodies selected from the cascade chain link unit serve as the high-frequency module. In the control period, the chain link unit body with the highest direct current capacitor voltage, the chain link unit body with the lowest direct current capacitor voltage, the chain link unit body with largest discharging to a direct current capacitor from a current pulse combination and the chain link unit body with largest charging to the direct current capacitor from the current pulse combination are found, pulses of the chain link unit body with the highest direct current capacitor voltage and pulses of the chain link unit body with the largest direct current capacitor discharging are exchanged, and pulses of the chain link unit body with the lowest direct current capacitor voltage and pulses of the chain link unit body with largest direct current capacitor charging are exchanged. According to the chained active power filter differentiation control method, the system switch losses can be remarkably reduced, and the balance effect and the compensation effect on the direct current capacitor voltages of the chain link unit bodies are guaranteed.

The invention discloses a millimeter-wave multi-channel space waveguide power distribution synthesizer and a method. The power distributor comprises a four-channel waveguide power distributors and four two-channel waveguide power distributors, a first port, four second ports and a first power allocation part are arranged in the four-channel waveguide power distributor, the first power allocation part is used for dividing one path of signal of electromagnetic wave into four paths of signals in equal proportion, a third port, two fourth ports and a second power allocation part are arranged in the each two-channel waveguide power distributor, the third port is connected with each second port, the second power allocation part is used for further dividing the four paths of signals into eight paths of signals in equal proportion, each path of signal is separately subjected to power amplification, the single path of signal subjected to amplification pass through the power synthesizer having the same structure with the power distributor, and multi-path power synthesis of electromagnetic signals are completed. The millimeter-wave multi-channel space waveguide power distribution synthesizer has the advantages of wide band, high capacity, high isolation, high efficiency, low loss and the like.

The invention relates to a fuel cell air supply system test device and a control method thereof. The system test device comprises an air main circuit, an air compressor cooling circuit, a heat transfer device cooling circuit and a humidification regulating circuit; wherein the air inflow pipeline of the air main circuit is in communication with the air inlet of an air compressor; the air outflow pipeline of the air main circuit is in communication with the air outlet of the air compressor; the coolant supply port of the air compressor cooling circuit is in communication with the coolant inlet of the air compressor; and the coolant recovery port of the air compressor cooling circuit is in communication with the coolant outlet of the air compressor; the air outflow pipeline of the air main circuit includes a heat transfer device and a humidification device; the coolant supply port of the heat transfer device cooling circuit is in communication with the coolant inlet of the heat transfer device; and the coolant recovery port of the heat transfer device cooling circuit is in communication with the coolant outlet of the heat transfer device. The technical solution of the invention can optimize the overall design of the fuel cell air supply system and ensure the performance and the service life of the fuel cell.

The present invention discloses an MMC capacitor voltage equalization control method based on driving signal logic processing. The method comprises: (1) collecting the current capacitor voltage values of submodules; (2) ranking the current capacitor voltage values of the submodules; (3) grouping and calculating the capacitor voltage difference values according to the ranking of the submodules.; and (4) performing logic processing of the original driving signals and distributing driving signals again for the submodules according to the grouping and the voltage difference values. The MMC capacitor voltage equalization control method based on a driving signal logic processing is low in real-time requirement, saved in the calculation resource of a controller and easy to be applied to a large-scale MMC system, does not need the detection of the leg current so as to reduce the communication complexity of the system and reduce the cost of partial current sensors, and does not need the addition of the hardware circuit so as to avoid extra system cost. Under the control of the MMC capacitor voltage equalization control method based on the driving signal logic processing, all the submodules share the same switch frequency and the switch stress, and the switch frequency is low so as to facilitate system thermal design, effectively recover from the capacitor voltage unbalance and improve the system reliability.

The invention relates to a light emitting diode surface light source device, which comprises a substrate and a plurality of light emitting diode chips arranged on the substrate in array type arrangement. The thickness of the substrate is more than 1 mm. The area of the light emitting diode chip is between 0.08 and 0.25 mm <2>; and the distance between every two light emitting diode chips is more than twice of the dimension of the chip. The light emitting diode surface light source device uses the chip with small dimension and controls the distance between the chips and the thickness of the substrate, can achieve the promotion of luminous efficiency of the whole surface light source device through utilization of the chip with the small dimension, can maintain the temperature of the chip in a lower state, reduce the amplitude needed for radiation and is further favorable for the following radiation design of the whole light emitting diode surface light source device.

The invention discloses a system for realizing the thermal simulation and control of an advanced telecom computing architecture (ATCA) subframe, which relates to the technical field of communication devices. The system comprises a micro-computer unit (MCU) singlechip, a DC / DC power module and a backboard 3V5 / 5V power supply, wherein the DC / DC power module supplies power to the MCU singlechip; and the MCU singlechip is directly connected with a 232 chip communicating with a personal computer (PC), an I2C communication chip communicating with a management disk, a temperature sensor, a heating module and a panel having a hot-plug switch. In the system for realizing the thermal simulation and control of the ATCA subframe, a thermal simulation test and the verification and evaluation of the actual radiating capacity of the system can be performed before the single disk development of the system so as to greatly reduce the risk of the design and development of a radiation part (for example, a fan single disk and the like) of the system, and simultaneously guide research and development engineers to select the type and shape of the radiation part and guide structural engineers to design the whole structure.

The invention provides a refrigerator, which comprises a box body defining a refrigerating chamber inside and a refrigerating chamber door body composed of a door body, a door liner and a foaming layer. A containing box with an ice making and cooling chamber is arranged at the top of the box body, an ice making evaporator and a fan are arranged in the ice making and cooling chamber, and a heatingpart is arranged on the ice making evaporator to heat and defrost the ice making evaporator; an ice making chamber with an ice maker is formed in the door liner; a top air supply chamber is formed inthe containing box, a top air inlet chamber and a top air return chamber are formed in the top air supply chamber, the bottom of the top air inlet chamber is respectively provided with a top air outlet and a top air return inlet penetrating through the top of the box body, and the upper part of the door liner is provided with an ice making chamber air inlet and an ice making chamber air return inlet penetrating through the ice making chamber. When the refrigerating chamber door body is closed, the ice making chamber air inlet communicates with the top air outlet, the ice making chamber air return inlet communicates with the top air return inlet, so that the amount of cooling supplied to the ice maker is increased and the ice making efficiency of the ice maker is improved.

The invention discloses a power supply module satisfying requirements for a power supply unit of an anti-interference antenna of an airborne satellite. The module comprises a casing, a circuit board and input and output connectors, the circuit board is sealed in the casing, and the input and output connectors are fixed in the two ends of the circuit board respectively; and the circuit board is provided with an input overcurrent protection circuit, a reversal connection preventive protection circuit, a DC filtering circuit, a peak voltage inhibition circuit, an overvoltage surge inhibition and self-recovery type overvoltage protection circuit, a filtering power storage circuit, an undervoltage protection setting circuit and a DC voltage conversion circuit. The sealed metal shielding casing and the metal connectors wrap the circuit board, a high electromagnetic shielding performance of the power supply module is ensured, the power supply module can satisfy index requirements, in the aspect of electrical performance, for the power supply unit of the anti-interference antenna of the airborne satellite of different models protection functions are complete, input and output misinsertion is prevented, the power supply index is kept accurate and consistent, the production efficiency can be improved, the research and development period is shortened, and the product and development cost is reduced.

The invention discloses an LED free-form curved face lens used for an optical microscope illumination system. The lens comprises three free-form curved faces. A cavity is formed in the center of the bottom face of the lens, wherein an LED is arranged in the cavity. One part of the cavity wall of the cavity is a cylindrical face which forms an inner side cylindrical face, and the other part of the cavity wall is a free-form curved face which forms an inner side free-form curved face. The inner side free-form curved face is located on the top of the inner side cylindrical face. The inner side free-form curved face and the inner side cylindrical face form an incidence face of the lens. The outer side face of the lens is a free-form curved face which forms an outer side free-form curved face. The middle of the top face of the lens is a free-form curved face which forms a top free-form curved face. The outer side of the top free-form curved face is a partial cylindrical face. The top of the partial cylindrical face is a plane which forms a top plane. A transmitting face of the lens is composed of the top free-form curved face and the top plane of the lens. The LED free-form curved face lens is compact in structure and small in size; the LED free-form curved face lens used for the optical microscope illumination system can form circular light spots which are uniform in illumination distribution on a target illumination face, and meanwhile the high optical efficiency is kept.

The invention provides a unipolar SPWM (Sine Pulse Width Modulation) dead-time-free modulation method of an H-bridge cascade multilevel converter. The method realizes the dead-time-free control of a chopper arm of the H-bridge converter through a digital logical circuit and certain dead time is set for a direction arm of the H-bridge converter only at every half working frequency cycle, so that the problem that the voltage on the direct-current side of the H-bridge cascade multilevel converter and the harmonic content of output current is influenced due to the dead time can be ignored. By introducing a control signal, the direction arm and the chopper arm realize interchange by taking two-divided frequency of working frequency as a cycle, the problem that the action of the switching device of the H-bridge converter is unbalanced under the situation of unipolar SPWM dead-time-free control is effectively solved, the thermal stability is good and the heat dissipation design and the long-term operation of the device are facilitated.

A high efficiency satellite transmitter comprises an RF amplifier chip in thermal contact with a radiant cooling element via a heat conducting element. The RF amplifier chip comprises an active layer disposed on a high thermal conductivity substrate having a thermal conductivity greater than about 1000 W / mK, maximizing heat conduction out of the RF amplifier chip and ultimately into outer space when the chip is operating within a satellite under normal transmission conditions. In one embodiment, the active layer comprises materials selected from the group consisting of GaN, InGaN, AlGaN, and InGaAlN alloys. In one embodiment, the high thermal conductivity substrate comprises synthetic diamond.

A light-emitting diode and a manufacturing method thereof relate to a light source structure, which solves the problem that the light-emitting angle of the existing LED cannot exceed 180° at most, and the lighting angle is limited. The light-emitting diode of the present invention uses high thermal conductivity glue on the carrier. One or more light-emitting chips are fixedly connected; the carrier and the light-emitting chip are electrically connected with wires, so that the carrier and the light-emitting chip become a semi-finished light-emitting diode; The invention utilizes the lens to condense the light of the light-emitting chip first, then refracts and scatters the light, so that the light shape is fuller and has a 3D light-emitting effect. The good heat dissipation structure and the popularization of the production process make the yield rate (99%) higher, which greatly reduces the manufacturing cost of the product.

A manufacturing method of a high-frequency LTCC circuit module substrate comprises the following steps: (1) manufacturing an insulating medium layer of the high-frequency LTCC module substrate; (2) manufacturing LTCC composite adhesive sheets; (3) manufacturing the high-frequency LTCC circuit module substrate. The manufacturing method has the advantages as follows: the manufacturing method is suitable for circuit design with different signal frequencies; a metal material with high electrical conductivity is used as a conductor material, so that the quality factor of a circuit system can be favorably improved and the flexibility of the circuit design is improved; requirements on large current, high temperature resistance can be met, and thermal design of electronic equipment is optimized; the high-frequency LTCC circuit module substrate is high in reliability and is applicable to a severe environment, and the service life of the substrate is prolonged; adhesion between the copper foil layers and the insulating medium layer is facilitated, and the adhesive property is good; the peeling strength of the high-frequency LTCC circuit module substrate is improved, and the high-frequency LTCC circuit module substrate is especially applicable to a high heat-resistant environment; the ranges of the thicknesses of the copper foils can be widened; the copper foils with different thicknesses are selected according to different load current, load power as well as intercepting capabilities of the copper layers, so that the thicknesses of the copper layers are utilized to the maximum extent as much as possible.

The invention discloses an LED collimating illumination optical lens for visual inspection. The LED collimating illumination optical lens for visual inspection comprises an incident surface and an emergent surface. The LED collimating illumination optical lens for visual inspection is characterized in that the lens comprises three free curved surfaces, a cavity allowing an LED to be installed therein is formed in the center of the bottom surface of the lens, part of the wall of the cavity is a columnar surface and forms the inner side columnar surface, and the other part of the wall of the cavity is a free curved surface and forms the inner side free curved surface; the inner side free curved surface is located at the top of the inner side columnar surface, and the incident surface is formed by the inner side free curved surface and the inner side columnar surface; the outer side face of the lens is a free curved surface and forms the outer side free curved surface, the middle of the top surface of the lens is a free curved surface and forms the top free curved surface, a step-shaped plane is arranged on the outer side of the top free curved surface and forms the top plane, and the emergent surface is formed by the top free curved surface and the top plane of the lens. The LED collimating illumination optical lens for visual inspection has the advantages that the optical efficiency is high, the structure is compact and the size is small; the LED collimating illumination optical lens can be used for visual inspection, and round light spots with high collimation can be formed on a target illumination surface.

Techniques for determining one or more heat transfer characteristic values of a structure, such as an electronic device, are disclosed. A heat flux vector magnitude and a temperature gradient vector magnitude for a portion of the structure are determined, and a product of the heat flux vector magnitude with the temperature gradient vector magnitude is obtained. More particularly, the dot product of the heat flux vector magnitude with the temperature gradient vector magnitude may be obtained to provide a bottleneck heat transfer characteristic value. Alternately or additionally, a cross product (or related operation) of the heat flux vector magnitude with the temperature gradient vector magnitude is obtained to produce a shortcut heat transfer characteristic value.

The invention provides a refrigerator which comprises a refrigerator body and a refrigerating chamber door body. A refrigerating chamber is defined by the refrigerator body, and the refrigerating chamber door body comprises a door main body, a door liner and a foaming layer; a containing box with an ice-making cold-supply chamber is arranged at the top of the refrigerator body, and an ice-making evaporator and a fan are arranged in the ice-making cold-supply chamber; an ice-making cavity with an ice-making machine is formed in the door liner, a top air feeding chamber is further formed in thecontaining box, a top air inlet chamber and a top air return chamber are formed in the top air feeding chamber, a top air outlet and a top air return opening which penetrate the top of the refrigerator body are formed in the bottom of the top air feeding chamber, and an ice-making chamber air inlet and an ice-making air return opening which communicate with the ice-making cavity are formed in theupper portion of the door liner; and when the refrigerating chamber door body is closed, the ice-making chamber air inlet communicates with the top air outlet, and the ice-making air return opening communicates with the top air return opening. According to the refrigerator, the ice-making cold-supply chamber and the top air feeding chamber are arranged at the top of the refrigerator body, the topspace of the refrigerator body is sufficiently used, sufficient cold capacity is provided for the ice-making machine, and the ice-making efficiency of the ice-making machine is improved.

The invention is suitable for the field of projection and provides a double-lamp illumination device and a projector. The device comprises two white light sources arranged in parallel, wherein a color wheel is arranged in the light emergent direction of the two white light sources, and comprises a plurality of pairs of filters; each pair of filters is symmetrical about the center of the color wheel and has the same filtering wave band, so that light output after light emitted by the two white light sources passes through any pair of filters has the same color; and a light equalizing system capable of directly receiving the output light of any pair of filters is arranged in an output light path of the color wheel. The light emitted by the two light sources is coupled in the light equalizing system in different spaces in a non-superposing mode by the color wheel with a symmetrical structure, so that the light energy utilization rate is increased; and the light equalizing system is high in light receiving capability, so that the device is high in light energy utilization rate and projection brightness. In addition, the positions of a first light source and a second light source are not required to be strictly limited, so that the device is conveniently radiated.

The invention provides a refrigerator which comprises a tank body defining a refrigeration chamber, refrigeration chamber door bodies each of which comprises a door body, a door lining and a foaming layer, door body side air inlet ducts and door body side air return ducts; the top of the tank body is provided with an accommodating tank which is provided with an ice making and cold supplying chamber; the ice making and cold supplying chamber is internally provided with an ice making evaporator and a fan; the ice making evaporator is provided with a heating component; each door lining is internally provided with an ice making cavity which is provided with an ice maker; the accommodating tank is internally provided with a top air supply chamber; the top air supply chamber is provided with a top air inlet duct and a top air outlet duct; the door body side air inlet ducts are configured to be connected and communicate with the top air inlet duct when the refrigeration chamber door bodies are closed; and the door body side air return ducts are configured to be connected and communicate with the top air outlet duct when the refrigeration chamber door bodies are closed. For the refrigerator provided by the invention, by arranging the ice making and cold supplying chamber and the top air supply chamber on the top of the tank body, the top space of the tank body is fully utilized, sufficient cold quantity is provided to the ice makers, and the ice making efficiency of the ice makers is improved.

The invention is applicable to the field of projection and provides a double-lamp illumination device and projection equipment. The double-lamp illumination device comprises two white light sources which are arranged in parallel, wherein a color wheel is arranged on an output light path of each of the two white light sources; the two color wheels have the same structure and synchronously rotate; and a light equalization system which can directly receive emergent light from the color wheels is arranged on the output light paths of the two color wheels. By the double-lamp illumination device, the light emitted from the two light sources is coupled to the light equalization system in a non-overlapped mode in different spaces, the interference loss generated by coupling two beams of light in the same narrow space is avoided, the problem that the light rays cannot fully enter an extremely small light entrance is solved, and the utilization rate of light energy is improved, so that the projection brightness is improved; and moreover, the light penetrating through the color wheels is not required to be strictly focused at the light entrance of the light equalization system, the positions of the first light source and the second light source are not strictly limited, and the thermal design of the device is improved.

The invention discloses a high-reliability switch, belongs to the field of electronics, and relates to the high-reliability switch. The high-reliability switch comprises a machine shell, a power supply module and a service module, wherein the power supply module and the service module are an individual closed structure respectively, and are plugged freely in the machine shell which has the design of air convection and heat dissipation through a chucking rail; the power supply module is arranged on the topmost part of the machine shell, and the service module is arranged below the power supply module; a backing plate is arranged on the rear panel of the machine shell; interfaces connected with exterior are formed at one end of the power supply module and one end of the service module, and contact pins are arranged at the other end; and the contact pins are connected with the backing plate. The modular fanless core switch is suitable for environment which needs multi-port switches.

The present disclosure discloses a power system with hot-swap with a buck converter. The power system comprises a front stage, a hot-swap stage and a load stage; wherein the hot-swap stage comprises: a buck converter having a switch operate at ON / OFF state to provide a desired output voltage to the load stage with low power loss and optimized thermal design.

A short trouble current limiter in particular relates to transmission and distribution network failure current limiter. It features on available bridge circuit type short trouble current limiter basic, rectifying bridge arm consisting of controllable solid-state switch tube series connected with current limiting resistance shunt circuit and then series connected with diode. The present invention realizes inductor and resistor combined current limiting, not only limiting failure current peak value but also steady state value.