43results about How to "Solve the problem of excessive loss" patented technology

The invention relates to a bidirectional PFC soft switch and a control method thereof, and belongs to the field of a circuit topology. The bidirectional PFC soft switch and the control method thereof,which are used for improving the integral efficiency of a converter, are provided. The bidirectional PFC soft switch comprises a main loop and an auxiliary branch, wherein the main loop comprises a first switch tube S1, a second switch tube S2, a first resonant capacitor C1, a second resonant capacitor C2, an inductor L, a first filtering capacitor Co1 and a second filtering capacitor Co2, the auxiliary branch comprises a third switch tube S3, a fourth switch tube S4, a resonant inductor Lr, a transformer T and a full-bridge rectification bridge, the main loop is a bidirectional half-bridge PFC converter, soft switching of the main loop under a boost mode or a buck mode is assisted to be completed by the auxiliary branch, and soft switching of a switch tube of the auxiliary branch is alsoachieved.

The invention discloses a high-frequency high-saturation-flux-density ferrite, a preparation method, an inductor and a transformer. The ferrite contains main components and auxiliary components in parts by mole: the main components contain 55-57 mol% of Fe2O3, 0-3.5 mol% of ZnO, and the balance MnO; the auxiliary components contain 0.01-0.03 wt% of Nb2O5, 0.02-0.10 wt% of CaCO3, 0.01-0.04 wt% of V2O5, 0-0.01 wt% of SiO2, 0-0.05 wt% of Ta2O5, 0-0.05 wt% of TiO2 and 0.10-0.25 wt% of Co2O3. The ferrite provided by the invention has high saturation magnetic flux density and can be suitable for inductors and transformers. Moreover, the inductor prepared from the high-frequency ultrahigh-saturation magnetic flux density manganese-zinc ferrite material has the advantages of small size and is capable of meeting the requirement for miniaturization of devices.

The invention discloses a power supply circuit, which comprises a first-stage circuit for converting input voltage into direct voltage, and a second stage circuit, wherein the second stage circuit comprises a main power switching circuit for converting the direct voltage into first output voltage, a first standby power switching circuit for converting the direct voltage into second output voltage, a feedback circuit for connecting the main power switching circuit and the first standby power switching circuit to generate a feedback signal according to the first and second output voltage so as to make the first standby power switching circuit adjust the second output voltage according to the feedback signal, a second standby power switching circuit for converting the first output voltage or the second output voltage into a standby power, and a power distribution circuit for outputting the first output voltage or the second output voltage to the second standby power switching circuit.

The invention relates to a method for splitting DL-p-hydroxymandelic acid racemate to prepare high purity D-p-hydroxymandelic acid. The method for splitting DL-p-hydroxymandelic acid is characterized in that (S)-(+)-2-amino-4-phenylethyl butyrate hydrochloride is used as resolving agent to perform chemical splitting to DL-p-hydroxymandelic acid. The method of the invention solves the problems of too many operation steps, long reaction time, low product purity, low yield and the like in the existing method for preparing high purity D-p-hydroxymandelic acid by splitting DL-p-hydroxymandelic acid racemate.

The invention discloses a color image-grey-scale image-color image conversion method, which comprises the following steps of: a coding process of converting a color image into a grey-scale image: carrying out RGB (Red, Green, Blue)-Ycbcr color space conversion on an original color image to obtain a brightness plane and two chrominance planes, and compressing the two chrominance planes to obtain compressed chrominance planes, the binary code stream is used as watermark information to be embedded into a brightness plane to obtain a watermark grayscale image; and a grayscale image reconstruction color image decoding process: extracting a binary code stream of a compressed chrominance plane from the grayscale image embedded with the watermark information, recovering the two chrominance planes according to the binary code stream, performing color space conversion from Ycbcr to RGB on the brightness plane and the two chrominance planes, and reconstructing a color image. According to the method, more color information is stored, a brightness plane with small distortion or without distortion can be obtained during reconstruction, and not only can a high-quality gray level image be obtained, but also a high-quality reconstructed color image can be obtained.

The invention discloses a lithium battery heating device and a heating method. The device comprises a battery management system, a self-heating power converter and a lithium battery, wherein the lithium battery and the self-heating power converter are connected with the battery management system, and the self-heating power converter is in closed-loop connection with the lithium battery; the battery management system is used for detecting the temperature of the lithium battery, generating a first signal according to the detected temperature and sending the first signal to the self-heating powerconverter; and the self-heating power converter is used for forming alternating current charging and discharging current on the lithium battery according to the first signal so as to heat the lithiumbattery. Therefore, according to the method provided by the invention, the lithium battery is directly heated by using the heat effect when the alternating current charging and discharging current passes through the internal resistor of the lithium battery, and the problem of overlarge energy loss in the heat transfer process is solved, so that the heating efficiency of the lithium battery is improved.

The invention discloses a switching power supplier provided with a frequency conversion device, comprising a rectifying device, a voltage transformation device, an output circuit, a switch device, a pulse width modulation control device, a feedback circuit, a pulse width modulation control device, and a frequency conversion modulation device used for modulating switch frequency of the pulse width modulation control device. The frequency conversion modulation device comprises a first frequency modulation resistance connected with the pulse width modulation control device, a first reference voltage circuit and a second reference voltage circuit respectively connected with the pulse width modulation control device, a second frequency modulation resistance in a bridge joint between the pulse width modulation control device and a first by-pass switch, and a third frequency modulation resistance in a bridge joint between the pulse width modulation control device and a second by-pass switch, wherein the first by-pass switch is connected with the first reference voltage circuit, and the second by-pass switch is connected with the second reference voltage circuit.

The invention discloses an alloy material for manufacturing a motor rotor and a preparation method thereof. The novel alloy material for manufacturing the motor rotor is composed of following raw materials according to weight percent: 95% of copper and 5% of iron. The preparation method comprises the steps of smelting, pouring, quenching and pouring the raw materials including copper and iron in sequence so as to obtain the novel alloy material for manufacturing the motor rotor ultimately, wherein the conductivity of the novel alloy material is 14245501.3 s/m, and the density is 8663.8 Kg/M<3>.The alloy material for manufacturing the motor rotor has good mechanical properties, and the technical problems of hard and brittle silicon steel sheets, bad mechanical properties, difficulty in processing and assembling into iron cores and the like when the silicon content is high are solved. The alloy material has good magnetic permeability and conductivity, the problem of high loss of a motor during operation can be preferably solved, the efficiency of the motor is effectively improved, normal operation of the motor is guaranteed, and the service life of the motor is prolonged.

The invention discloses a battery heating assembly and a manufacturing process thereof, and belongs to the technical field of new energy automobile battery devices. The assembly comprises a bottom support serving as a base, a lining assembly, a metal core used for heat transfer and an electromagnetic heating ring used for heating the metal core are arranged in the bottom support, the bottom of the metal core is arranged on the bottom support, and the electromagnetic heating ring can be arranged on the outer side of the metal core in a sleeving mode or stably assembled through the lining assembly. The electromagnetic heating ring is electrified to heat the metal core, and heat of the metal core is transferred out for heating; and the problems that the cruising ability of a new energy vehicle adopting electricity as energy is greatly reduced under the condition that the environment temperature is too low or low in winter, and the loss of a battery is large in the using process are solved, the heating efficiency can be effectively improved in an electromagnetic induction heating mode, the activity of the battery is effectively improved, the cruising ability of the new energy vehicle is prolonged, and the service life of the battery is effectively prolonged.

The invention discloses a reverse connection prevention circuit, which is connected to an external interface J1 composed of a first pin and a second pin, and comprises an NMOS tube M1, a PMOS tube M5,a first diode D4 and a second diode D5, wherein the negative electrode of the first diode D4, the positive electrode of the second diode D5, the grid electrode of the NMOS tube M1 and the grid electrode of the PMOS tube M5 are all connected to the first pin of the external interface J1, the drain electrode of the NMOS tube M1 and the drain electrode of the PMOS tube M5 are connected to the secondpin of the external interface J1, the source electrode of the NMOS tube M1 is connected with the positive electrode of the first diode D4, the source electrode of the PMOS tube M5 is connected with the negative electrode of the second diode D5, and two ends of a load RL are respectively connected with the positive electrode of the first diode D4 and the negative electrode of the second diode D5.The normal work of the load RL can be ensured when the external interface J1 is positively connected or negatively connected.

The invention discloses an ultra-broadband power divider based on ridge-gap waveguide technology, relates to the field of microwave/millimeter wave passive devices, and is specifically an ultra-broadband power divider/combiner based on novel ridge-gap waveguide technology. In order to overcome the shortcomings in the prior art, the operating bandwidth of the solid-state power amplifier is improved so that it can work effectively in several frequency bands, thereby saving design cost. The invention proposes an ultra-wideband ridge-gap waveguide power divider/combiner, which has the advantages of large power capacity, ultra-wideband (3 octaves), compact structure, low loss, good amplitude-phase consistency, and easy processing and assembly. .

The invention relates to the technical field of power equipment, and particularly discloses a radial iron core cake-based iron core assembly structure. The radial iron core cake-based iron core assembly structure comprises an upper-part fastening fitting, a lower-part fastening fitting, iron core posts and upper-lower fastening bolts, wherein multiple groups of iron core posts are arranged betweenthe upper-part fastening fitting and the lower-part fastening fitting, each group of iron core post is fixedly connected with the upper-part fastening fitting and the lower-part fastening fitting bythe upper-lower fastening bolts, one end of each upper-lower fastening bolt extends out of the upper-part fastening fitting, the other end of the upper-lower fastening bolt extends out of the lower-part fastening fitting, each group of iron core post comprises a plurality of radial iron core cakes, and the plurality of radial iron core cakes of each group of iron core post are arranged in a lamination way. The invention also discloses a reactor. When the radial iron core cake-based iron core assembly structure provided by the invention is applied to the reactor, the loss can be effectively reduced, and the problem of relatively large loss in the prior art is solved.

The invention discloses a structure capable of reducing heat loss of a high-temperature pipeline. The structure comprises a lining barrel, a metal spun silk net, a thermal insulation block, a metal barrel, a metal wire and a high-temperature pipeline outer shell; the metal spun silk net wraps the outer surface of the lining barrel; the lining barrel is sleeved by the metal barrel; the thermal insulation block is filled between the metal barrel and the metal spun silk net; the metal wire is bundled on the outer surface of the metal barrel; the high-temperature pipeline outer shell is positioned on the outermost layer of the structure for reducing the heat loss of the high-temperature pipeline. The structure disclosed by the invention can be used for realizing thermal protection of the high-temperature pipeline, and the design thickness of the high-temperature pipeline can be reduced, and the heat loss of an air flow in the pipeline can be reduced.

The invention discloses a high frequency power supply with high efficiency and low loss. After passing through a resistor R1, an audion Q1 and an audion Q2, an input signal reaches a field effect tube M1 through a resistor R111 and outputs a signal through a resistor R100; a voltage-regulator tube D1 enables the field effect tube to work at a certain voltage. A high power tube works at an open zone and a close zone after being driven by a power amplifying tube, and then connected to a AT89S2051 singlechip pin P1.0-P1.5 of a control unit; through the action of a singlechip, the output current is effectively controlled, and the purposes of preventing a molybdenum wire from burning and breaking for excessive current and reducing loss of the molybdenum wire are achieved. Through the principle, the effect of debugging the software write on a machine tool is very good, the normal processing efficiency is up to more than 8,000 per hour, and also 12,000 per hour as the fastest. The loss of the molybdenum wire is one time higher than that in the past, so that the problems of low processing efficiency and high molybdenum wire loss of the quick thread cutting high-frequency power are solved effectively, the loss of each company is reduced; the high efficiency and high-benefit operation of every company is guaranteed; therefore, the high frequency power supply has a very good effect.

The invention discloses a kind of collector heat pan bearer it concludes the bearer body setting a open hole corresponding the head of oven in the center and the on the bearer body said above sets up a pan floor fasten flaw used to support the pan floor and the internal of bearer body sets up many fire-resisting reverse hot plate which can assemble the burning flame to the pan floor. By mirroring of the fire-resisting reverse hot plate to the igniting flame the flame which is generated during the igniting can be assembled to the pan floor so it not only resolve the problem that the ordinary pan bearer losses so lots of quantity of heat when it is igniting but also improve the work environment of chicken and save the energy.