38results about How to "High voltage gradient" patented technology

The invention discloses a lightning arrester zinc oxide varistor and a preparation method thereof. The lightning arrester zinc oxide varistor is prepared by sintering the raw materials of 85-90% of zinc oxide, 0.1-0.5% of calcium oxide, 4-7% of bismuth trioxide, 4-7% of antimony trioxide, 0.1-1% of manganese carbonate and 0.1-1% of aluminum nitrate. According to the lightning arrester zinc oxide varistor, the added calcium oxide can be effectively wrapped outside zinc oxide grains during sintering to inhibit grain growth, reduce the size of the grains and further improve the voltage gradient and the flow capacity of the grains. The lightning arrester zinc oxide varistor is a system prepared from the zinc oxide, the calcium oxide, the bismuth trioxide, the antimony trioxide, the manganese carbonate and the aluminum nitrate, thereby being low in raw material cost; the prepared lightning arrester zinc oxide varistor is uniform and stable in internal structure high in large current impactresistance.

A FET driving circuit includes: inputs into which a DC voltage is inputted; outputs connected to gate and source electrodes of a FET; a switch; a capacitance connected across the switch; and an LC resonance circuit connected in series with the switch across the inputs. A voltage generated across the switch during switching is outputted to drive the FET. The LC resonance circuit has a first connector connected to one input and a second connector connected to the switch, and is configured with a path including an inductance and a path including an inductance and a capacitance. An impedance between the first and second connectors has two resonant frequencies. The impedance has a local maximum at the lower resonant frequency, which is higher than a switching frequency, and a local minimum at the higher resonant frequency, which is around double the switching frequency.

The invention discloses a heat preservation device for microwave sintering and a microwave sintering method of zinc oxide pressure-sensitive ceramic. The method comprises the following steps: carryingout ball milling on zinc oxide, bismuth oxide, cobaltosic oxide, manganese carbonate, antimony oxide, nickel sesquioxide, titanium dioxide, an aluminum nitrate nonahydrate solution, a dispersing agent and the like, granulating, carrying out dry pressing molding, discharging glue, putting into a heat preservation device, and carrying out microwave sintering to obtain the zinc oxide pressure-sensitive ceramic. The heat preservation device comprises a box body, a high crucible, a short crucible, powder for pressing a ceramic chip green body, an end cover and a thermocouple; the high crucible isstacked on the short crucible; end covers are arranged on the top surface and the bottom surface in the box body; the thermocouple and the high crucible are in connection. The heat preservation deviceis adopted for microwave sintering, the temperature difference between materials and the surrounding environment is reduced, and the phenomena of cracks, deformation and uneven colors are eliminated.Compared with a traditional method, the method of the invention has the advantages that the sintering time is shortened by 50%, volatilization of low-melting-point substances and abnormal growth of crystal grains are reduced, and the performance of the obtained product is better than that of the traditional method.

The invention provides a preparation method of large-discharge-current-capacity and low-residual-voltage voltage-sensitive ceramic used for an ultrahigh voltage power transmission system. The ceramic is prepared from zinc oxide ZnO, bismuth oxide Bi2O3, antimonous oxide Sb2O3, manganese dioxide MnO2, chromic oxide Cr2O3, cobalt oxide Co2O3, silicon dioxide SiO2, silver oxide Ag2O, Ga(NO3)3 and aluminium nitrate Al(NO3)3. The method has the advantages that the leakage current is restrained, the ageing performance of a ZnO voltage-sensitive resistor manufactured according to the formula is more stable by adding elements Al and Ga together, and the defect that when only Ag ions are added, the ageing performance of the voltage-sensitive resistor is not stable is overcome.

A medium voltage varistor comprises the following components by mass: 93-98 parts of ZnO, 0.4-5 parts of Co2O3, 0.5-4 parts of Bi2O3, 18-30 parts of SbO, 0.05-1 part of Ni2O3 and 0.3-0.8 part of MnCO3. The components of the medium voltage varistor are subjected to mixing operation, wet ball milling operation, mixing granulation operation, dry pressing operation, pre-sintering operation, post-sintering operation, silver layer coating operation, heat treatment operation and curing operation to obtain the medium voltage varistor. According to experimental test results, the voltage gradient of themedium voltage varistor is 220-280 (V / mm), so that the varistor has the advantages of good stability and high voltage gradient.

The invention provides a preparation method of large-discharge-current-capacity and low-residual-voltage voltage-sensitive ceramic used for an ultrahigh voltage power transmission system. The ceramic is prepared from zinc oxide ZnO, bismuth oxide Bi2O3, antimonous oxide Sb2O3, manganese dioxide MnO2, chromic oxide Cr2O3, cobalt oxide Co2O3, silicon dioxide SiO2, silver oxide Ag2O, Ga(NO3)3 and aluminium nitrate Al(NO3)3. The method has the advantages that the leakage current is restrained, the ageing performance of a ZnO voltage-sensitive resistor manufactured according to the formula is more stable by adding elements Al and Ga together, and the defect that when only Ag ions are added, the ageing performance of the voltage-sensitive resistor is not stable is overcome.

A FET driving circuit includes: inputs into which a DC voltage is inputted; outputs connected to gate and source electrodes of a FET; a switch; a capacitance connected across the switch; and an LC resonance circuit connected in series with the switch across the inputs. A voltage generated across the switch during switching is outputted to drive the FET. The LC resonance circuit has a first connector connected to one input and a second connector connected to the switch, and is configured with a path including an inductance and a path including an inductance and a capacitance. An impedance between the first and second connectors has two resonant frequencies. The impedance has a local maximum at the lower resonant frequency, which is higher than a switching frequency, and a local minimum at the higher resonant frequency, which is around double the switching frequency.

The invention relates to a large-discharge-current-capacity low-residual-voltage high-gradient zinc oxide piezoresistor ceramic. The invention is characterized in that the ceramic comprises the following formula components: zinc oxide ZnO, bismuth oxide Bi2O3, antimony trioxide Sb2O3, manganese peroxide MnO2, chromic oxide Cr2O3, cobaltic oxide Co2O3, silicon dioxide SiO2, silver oxide Ag2O, gallium nitrate Ga(NO3)3 and yttrium nitrate Y(NO3)3. By using the ceramic, the leakage current is inhibited; and by adding the Y and Ga elements, the ZnO piezoresistor prepared according to the formula has more stable aging resistance, thereby overcoming the defect that the leakage current can not be inhibited when the single Ag ions are added.

The invention relates to a zinc-oxide piezoresistor raw material, a preparation method thereof and a piezoresistor. The zinc-oxide piezoresistor raw material comprises the following components by mole percent: 91.48-98.03% of zinc oxide, 0.5-2.0% of bismuth trioxide, 0.5-2.5% of silicon dioxide, 0.35-1.5% of cobaltosic oxide, 0.5-1.0% of manganese carbonate, 0.1-0.5% of chromium oxide, 0.01-2.0% of yttria and 0.0001-0.001% of aluminium nitrate. The zinc-oxide piezoresistor raw material does not antimony, and due to the silicon dioxide, the characteristic of the piezoresistor is improved, the surface state density is increased, the voltage gradient, the barrier height and the nonlinear coefficient are improved, the leakage current is reduced and the current impact resistance is enhanced; due to the yttria, the conductivity, the current impact resistance, the nonlinear coefficient and the voltage gradient are improved, the limiting voltage rate and the leakage current are reduced, the grain growth is inhibited and the zinc-oxide piezoresistor has higher voltage gradient and excellent electrical property.

The invention relates to a preparation method of a zinc oxide varistor sheet. The method includes the steps of: preparing a green body by using zinc oxide as the main material and auxiliary materials including bismuth oxide as raw materials, sealing the green body and then performing microwave sintering, and the microwave sintering process is as follows: heating to 1000-1100° C., Heat preservation for 1-10min; then cool down to 850-900°C, heat-retain for 1-3h, and finally cool to room temperature to obtain a zinc oxide varistor sheet. The method proposed by the invention greatly shortens the sintering time, reduces the energy consumption in the sintering process, and improves the electrical properties such as the voltage gradient and energy tolerance of the zinc oxide varistor sheet.

The invention discloses a piezoresistor material. The piezoresistor material is prepared from the following raw materials in parts by weight: 98-100 parts of zinc oxide, 50-52 parts of yttria, 3-5 parts of titanium dioxide, 50-52 parts of ytterbia, 2-4 parts of stannic oxide, 1-3 parts of selenium oxide, 5-7 parts of strontium titanate, 2-4 parts of rhenium oxide, 2-4 parts of manganese carbonate, 6-8 parts of silicon dioxide, 4-6 parts of aluminum nitrate and 10-12 parts of rare earth sinter. Yttrium ions and ytterbium ions, with radii close to those of zinc ions, are introduced, so that a traditional formula with zinc oxide as the main component is replaced with a new formula with zinc oxide, yttria and ytterbia as main components. In combination with various additives in the new formula, the prepared piezoresistor material has higher nonlinear coefficients, lower leakage currents, higher heavy current resistance capacity and higher voltage gradient.

The invention discloses an electric osmosis filter pressing based sewage sludge co-dehydration device, comprising an electric osmosis squeezing container (3), an anode plate (4) and a cathode plate (5), wherein the anode plate (4) and the cathode plate (5) are arranged in the electric osmosis squeezing container (3), sludge particulates move towards the anode plate and water molecules move towards the cathode plate under the influence of an electric field force, and a pressure is exerted between the anode plate and the cathode plate such that electrically osmosed water flows out of an electric osmosis squeezing dehydration device. After the above electric osmosis dehydration is completed, a low water content of sludge of the anode plate (4) is realized, when the sludge becomes dry, the electric osmosis dehydration is stopped, and the pressure between the anode plate (4) and the cathode plate (5) is increased to realize an ultra-high pressure mechanical filter pressing dehydration, so that the water content between the anode plate and the cathode plate is uniform. According to the electric osmosis filter pressing based sewage sludge co-dehydration device disclosed by the invention, as a co-dehydration means in the combination of an electric osmosis coupling dehydration and an ultra-high pressure mechanical dehydration is employed, energy consumption for the dehydration is reduced greatly, and a lower water content of the sludge treated according to the invention is realized.

The invention relates to a zinc oxide resistance sheet and a preparation method thereof. The zinc oxide resistance sheet is sintered from the following molar percentages of raw materials: 94.5% to 99% of zinc oxide base material, 0.2% to 1.6% of tungsten oxide, 0.7% to 3.6% of calcium oxide; 94.5% to 99% of the The zinc oxide base material includes raw materials with the following molar percentages: 91%-94% of zinc oxide, 1%-1.5% of cobalt oxide, 1.5%-2.5% of bismuth oxide and 0.6%-1% of manganese oxide. The zinc oxide resistance sheet proposed by the present invention can improve its electrical properties such as voltage gradient on the basis of reducing sintering energy consumption, wherein the voltage gradient can be as high as 547V / mm, and the flow capacity can reach 350J / cm 3 . The invention also proposes a preparation method of the zinc oxide resistor, including granulation, tablet pressing, pre-sintering and sintering. The method improves the performance of the zinc oxide resistor and is also beneficial to reduce energy consumption.

The invention discloses a nonlinear cylindrical pressure sensitive resistor and application thereof. The nonlinear cylindrical pressure sensitive resistor is composed of a pressure sensitive resistor ceramic wafer and a non-continuous electrode. Due to doping of a zinc oxide material in the pressure sensitive resistor ceramic wafer, grains of the zinc oxide are refined, the surface density of the pressure sensitive resistor ceramic wafer is increased, the characteristics of the pressure sensitive resistor are improved, and the current-force impact resistance and nonlinear coefficient of the resistor are improved, so that the pressure sensitive resistor has high voltage gradient and beneficial electrical properties, reaches a nanosecond over-voltage response speed and is fast in over-voltage recovery and zero in follow current. The pressure sensitive resistor disclosed by the invention is safe and non-toxic in material and harmless to the human body and environment and can be widely applied to over-voltage protection of power diodes, silicon stacks, medium / low-power silicon controlled rectifiers and the like.

The invention discloses a safe environment-friendly nonlinear piezoresistor and application thereof. The safe environment-friendly nonlinear piezoresistor is composed of a piezoresistor ceramic wafer and a conductive electrode. The piezoresistor ceramic wafer is composed of zinc oxide, manganese dioxide, silicon dioxide, titanium dioxide, nonacobalt octasulfate, dinickel trisulfate, silicon carbide, zirconium nitride, zirconium titanate and copper calcium titanate. The surface density of the piezoresistor ceramic wafer is increased, the characteristics of the piezoresistor are improved, and the current impact resistance and nonlinear coefficient of the resistor are enhanced, so that the piezoresistor has higher voltage gradient and favorable electric properties. The overvoltage response speed reaches the nanosecond level; and the piezoresistor can quickly restore without after flow after overvoltage. The piezoresistive material is safe and nontoxic, and is harmless to the human body and environment.

The invention discloses a piezoresistor with a low residual voltage ratio and application of the piezoresistor. The piezoresistor with the low residual voltage ratio consists of a piezoresistor chip, a silicone rubber sealing layer, an insulated sealing layer, an electrode and an electrode lead wire. A zinc oxide material is doped, so that grain sizes of zinc oxide are refined, and surface density of a piezoresistor is increased, and therefore, the purpose of reducing the residual voltage ratio of the piezoresistor is achieved, current power impact resistance and a nonlinear coefficient of the piezoresistor are improved, so that the piezoresistor has relatively high voltage gradient.