Patents
Literature
Hiro is an intelligent assistant for R&D personnel, combined with Patent DNA, to facilitate innovative research.
Hiro

115results about How to "High power factor" patented technology

LED luminaire driving circuit with high power factor

The present invention relates to an LED luminaire driving circuit with high power factor, comprising: a filter unit, a rectifier unit, a transformer unit, a power switch unit, a zero current detecting unit, a feedback unit, an error amplifier unit, and a power switch driving unit. Particularly, the LED luminaire driving circuit proposed by the present invention does not include any optocoupler feedback circuits, so it is able to effectively reduce the entire circuit manufacturing cost of this LED luminaire driving circuit. Moreover, this LED luminaire driving circuit can selectively work under CCM operation or DCM operation with high power factor (PF˜1), and provide stable output voltage signal and output current signal to load end. In addition, this LED luminaire driving circuit performs excellent stability and current modulation error rate (<±3%).
Owner:NAT CHUNG SHAN INST SCI & TECH

Method for preparing pyroelectric material Ag complex (Ca***La*)*Co*O

The invention discloses a preparation method of thermoelectric material Ag compound (Ca(1-X)LaX)3Co4O9, and relates to the preparation method of Ag compound oxide thermoelectric material. The invention resolves the problems that the distribution of Ag phases in an Ag compound Ca-Co-O-based oxide is not even, the size of Ag phase particles is large, thereby leading that current carrier transporting loop is formed between Ca-Co-O-based oxide crystal grains, and leading Seebeck coefficient of the Ag compound Ca-Co-O-based oxide to be reduced evidently, and the existence of lanthanon results in decreasing the electrical conductivity of the Ca-Co-O-based oxide. The preparation methods comprises that firstly, calcium nitrate, cobalt nitrate and lanthanum nitrate are dissolved in distilled water; secondly, citric acid is add; thirdly, silver nitrate is added; fourthly, organic monomers and network agent are added; fifthly, initiating agent is added; sixthly, microwave dry is performed; seventhly, calcination is operated; eighthly, the spark plasma sintering is performed. The distribution of Ag phases in Ag compound (Ca(1-X)LaX)3Co 4O9 prepared by the methods of the invention is even, the size of the Ag phase particles is smaller than 500 nm, and the current carrier transporting loop is not formed. The Seebeck coefficient of the Ag compound (Ca(1-X)LaX)3Co4O9improves 1.7 percent to 4.9 percent than that of the Ca3Co4O9, the electrical conductivity improves 13.3 percent to 38.9 percent, and the power factor improves 21.6 percent to 35.1 percent.
Owner:HARBIN INST OF TECH

K hole doped polycrystalline SnSe and preparation method therefor

The invention relates to a K hole doped polycrystalline SnSe and a preparation method therefor, and belongs to the technical field of energy materials. The method comprises the steps: firstly taking high-purity Sn, K and Sn elementary substances as raw materials, and enabling the raw materials to be prepared into compound powder through an improved mechanical alloying method; secondly employing a spark plasma sintering method, and adjusting the mechanical alloying method and the technological parameters of the spark plasma sintering, thereby achieving the effective doping of K elements, and obtaining K hole doped polycrystalline SnSe through preparation, wherein the atomic ratio of Sn: K: Se is equal to (1-x): x: 1, and x is greater than zero but not greater than 0.1. The K hole doped polycrystalline SnSe is low in heat conductivity, and is high in carrier concentration, power factor and ZT value, wherein the heat conductivity can decrease to 0.20W / mK at the temperature of 773K, and the maximum power factor and the maximum thermoelectricity optimum value ZT respectively reach 350 [mu]W / mK2 and 1.08. The method optimizes the thermoelectric performances, is simple and convenient in technology, is low in cost, and is high in practicality.
Owner:深圳热电新能源科技有限公司

Method for preparing elemental tellurium based composite pyroelectric material

The invention relates to a method for preparing an elemental tellurium based composite pyroelectric material and belongs to the field of pyroelectric materials. The pyroelectric material is characterized by having a chemical formula of Te1-x(Sb2Se3)x, wherein x is not smaller than 0 and not greater than 0.2. The preparation method disclosed by the invention comprises the following steps: weighingvarious raw material ingredients according to a mole fraction proportioning ratio of the chemical formula, and encapsulating Te cakes, Sb powder and Se powder into a carbon-plated quartz tube throughvacuum encapsulation; then, smelting the quartz tube in a vertical tube type furnace; then, carrying out annealing treatment; and finally, grinding an obtained cast ingot into fine powder, then, carrying out spark plasma sintering, so as to obtain dense mass which has very low thermal conductivity and relatively high pyroelectric properties, wherein the pyroelectric Q-value reaches 0.95. Accordingto the method, the pyroelectric properties of the elemental tellurium based composite pyroelectric material are improved through a smelting process, an annealing process and a spark plasma sinteringprocess. Compared with the prior art, the method has the advantages that through introducing an antimony selenide component, the cooperated optimization of carrier concentration and lattice thermal conductivity is achieved, and the process flow is simple and controllable and is low in cost.
Owner:TAIYUAN UNIV OF TECH

Method for preparing high thermoelectrical antimony telluride micro-nano crystal and block material thereof

The invention discloses a method for preparing a high thermoelectrical antimony telluride micro-nano crystal and a block material thereof. The method comprises the following steps: dissolving an antimony precursor into polyol, then mixing the obtained solution with a tellurium precursor and a complexing agent, heating the mixed solution at a temperature of 140 to 180 under stirring, cooling to a temperature of 100 to 120 DEG C, adding a reducing agent, carrying out reactions at a temperature of 120 to 180 DEG C for 6 to 48 hours so as to obtain precipitate, washing the obtained precipitate by waterless ethanol until the washing liquid is neutral, drying the washed precipitate in vacuum so as to obtain antimony telluride micro-nano crystal, cold-pressing the obtained antimony telluride crystal into a sheet, and then carrying out annealing for 2 to 24 hours at a temperature of 300 to 400 DEG C in an atmosphere of mixed gas composed of Ar and H2 with a volume ratio of 92%:8% so as to obtain an antimony telluride block material. The obtained antimony telluride micro-nano crystal and block material thereof have the characteristics of high purity and good thermoelectrical property. Moreover the preparation method has the advantages of simpleness, low cost, easiness in repeating, and suitability for massive production, and thus has a good commercialization prospect.
Owner:GUANGZHOU INST OF ENERGY CONVERSION - CHINESE ACAD OF SCI

LED constant current PWM drive circuit and three-primary-color LED light mixing driving circuit

The invention provides an LED constant current PWM drive circuit and a three-primary-color LED light mixing driving circuit. The LED constant current PWM drive circuit comprises a three-end bilateral switch circuit, a PWM waveform signal generating circuit and an LED constant current drive circuit, wherein the three-end bilateral switch circuit is connected with an alternating current power source and used for converting a sine alternating current signal provided by the alternating current power source into a sine chopped wave waveform signal; the PWM waveform signal generating circuit is connected with the three-end bilateral switch circuit and used for generating a PWM waveform signal by utilizing the sine chopped wave-shaped signal; the LED constant current drive circuit is connected with the PWM waveform signal generating circuit and used for controlling the on-off state of an LED light source by utilizing the PWM waveform signal, and the constant current PWM driving of an LED is achieved. According to the LED constant current PWM drive circuit, the direct driving load of the three-end bilateral switch circuit is a resistive load rather than a capacitive load, and therefore the technical scheme can guarantee high-power factors, and the quality of the whole power grid cannot be affected.
Owner:INST OF SEMICONDUCTORS - CHINESE ACAD OF SCI

Pb/Ba double doped BiCuSeO thermoelectric material and preparation method thereof

The invention relates to a Pb / Ba double doped BiCuSeO thermoelectric material and a preparation method thereof. The method is characterized in that the material is prepared from bismuth oxide powder,copper powder, selenium powder, bismuth powder, lead powder and barium oxide powder in mass ratio of (1-x):3:3:(1-4x):3x:3x; the powders are mixed uniformly, ball milling is conducted on the powders in a mill pot under an inert atmosphere for 5-12 hours; the milled PbxBaxBi1-2xCuSeO powder is put into a mould, the mould is placed in a plasma activated sintering furnace, meanwhile the temperature is increased to 500-700 DEC G in a uniform speed and the pressure is increased to 30-100 MPa in a uniform speed, the temperature maintaining and pressure maintaining are conducted, then the temperatureis reduced to the normal temperature in a uniform speed, and the pressure is reduced to the normal pressure in a uniform speed; the sintered mould is taken out, and demoulding is conducted to obtainthe Pb / Ba double doped BiCuSeO thermoelectric material, wherein 0.01<=x<=0.08. The method has the advantages of simple process, short production cycle and high production efficiency, and the preparedproducts have the advantages of high purity, low thermal conductivity, high electrical conductivity, good electrical transmission performance, high power factor and high non-dimensional thermoelectricfigure of merit ZT.
Owner:WUHAN UNIV OF SCI & TECH

Indium sulfide doped cuprous sulfide thermoelectric material and preparation method thereof

The present invention discloses an indium sulfide doped cuprous sulfide thermoelectric material and a preparation method thereof, wherein the general formula is Cu2S-xIn2S3, and x is the mole percentof indium sulfide to cuprous sulfide. The preparation method comprises two steps such as manual grinding and discharge plasma sintering, and specifically comprises: weighing a certain mass of cuproussulfide and the corresponding molar percentage of indium sulfide, completely mixing the two materials, grinding for 30-60 min by using an agate mortar, and completing sintering, doping and material preparation in one step by using a discharge plasma sintering technology (SPS) to obtain the compact bulk thermoelectric material. According to the present invention, the preparation method is simple, rapid and efficient, and the power factor of cuprous sulfide is significantly improved so as to significantly improve the thermoelectric performance of cuprous sulfide; and by introducing indium sulfide, the phase change of cuprous sulfide at the high temperature is suppressed, such that the practical application of the material can be easily achieved.
Owner:DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI

Single-crystal tin selenide pyroelectric thin film and preparing method thereof

The invention relates to a single-crystal tin selenide pyroelectric thin film and a preparing method thereof, and belongs to the field of pyroelectric materials. The preparing method of the single-crystal tin selenide pyroelectric thin film includes the following steps of taking a substrate, putting the substrate in cleaning liquid for ultrasonic cleaning for 20 minutes, drying the substrate for 2hours at 60-150 DEG C after cleaning, taking out the substrate to be naturally cooled, putting the processed substrate onto a spinner, dropwise adding dispersion liquid onto the surface of the substrate, conducting spinning for 10-60 seconds, taking out the substrate after spinning, drying the substrate for 5-10 minutes at 200 DEG C to obtain a buffering layer substrate, putting a tin selenide sputtering target material and the prepared buffering layer substrate into a high-vacuum multifunctional magnetron sputtering film coating instrument for vacuumizing, heating the buffering layer substrate, and introducing inert gas for sputtering for 20-60 minutes to obtain the single-crystal tin selenide pyroelectric thin film. The preparing method has the advantages that the preparing process is simple, and the prepared single-crystal tin selenide pyroelectric thin film is high in single crystallinity and power factor.
Owner:ZHEJIANG NORMAL UNIVERSITY

Electric motor having an approximated ellipsoid shaped rotor

In one embodiment, a motor has a rotor with an approximated ellipsoid shape defined by a plurality of lattice lines and a plurality of lattice points. The motor has a matching stator that is configured to be utilized in conjunction with the approximated ellipsoid shaped rotor and to accommodate the approximated ellipsoid shaped rotor. The motor may also includes a housing unit configured to hold the matching stator that is utilized in conjunction with the approximated ellipsoid shaped rotor, and an enclosure lid configured to be used by the housing unit. The enclosure lid may be configured to hold the rotor having the approximated ellipsoid shape with a bearing.
Owner:FXQ ENG GRP
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products