125 results about "Voltage coefficient" patented technology

By improving profile of impurity concentration in a channel portion of an FET or an IGBT of a trench gate type, variation of threshold value is lessened, and a destruction caused by current concentration is prevented while suppressing deterioration of cut-off characteristics. An island of a base region of p-type is formed in a semiconductor substrate of n-type by carrying out high acceleration ion implantation twice followed by annealing, so that the impurity concentration profile in a channel portion changes gradually in a depth direction. Accordingly, it is possible to lessen variation of the threshold value and to reduce pinch resistance while at the same time improving sub-threshold voltage coefficient and conductance characteristics.

A capacitor has first and second conducting plates and a dielectric region between the plates, wherein the dielectric region comprises two dielectric materials for each of which the variation of capacitance with voltage can be approximated by a polynomial having a linear coefficient and a quadratic coefficient, and wherein the quadratic coefficients of the two dielectric materials are of opposite sign. The capacitor comprises for example a first capacitor (42) and a second capacitor (44) that one connected in an anti-parallel manner. The insulating layer (18) of the first capacitor comprises silicon nitride and the insulating layer (16) of the second capacitor comprises silicon dioxide

The invention provides a maximum power tracking control method of a voltage variable photovoltaic system which adapts to weather conditions, belonging to the photovoltaic power generation technical field; firstly, three data of voltage, current outputted by a photovoltaic battery and temperature of a photovoltaic battery plate at a moment are collected by a collection circuit, and an open circuit voltage value and an illuminating value at the moment are worked out based on the collected data; secondly, an approximate optimum output voltage value is obtained by a real optimized voltage coefficient multiplying the open circuit voltage value, and the temperature and the illumination are compensated, which obtain a real optimum output voltage value, and further a real optimum output current value is obtained; thirdly, an output value of a load end is compared with the real optimum output voltage value and the real optimum output current value, and a maximum power output is realized based on the proportional plus integral control on a fluctuating chopper circuit and a double closed loop of the voltage and the current. The maximum power tracking control method of the voltage variable photovoltaic system improves the output power of a photovoltaic power generation system and simultaneously ensures the operational stability and reliability of the system.

A method for the on-board functional diagnosis of a soot sensor and detection of further constituents in the soot in a motor vehicle having an internal combustion engine. The soot sensor is connected electrically to an evaluation circuit in the motor vehicle. A faulty soot sensor and/or further constituents in the soot can be detected in an inexpensive way. The evaluation circuit measures the voltage coefficient of the soot sensor and detects the defectiveness of the soot sensor and/or the presence of further constituents in the soot using the voltage coefficient of the soot sensor.

Existing magnetoelectric materials relying on the use of metallic or ceramic magnetostrictive materials and ceramic piezoelectric materials as their constituent phases may have three problems. First, the operational frequency may be limited to a few kilohertz due to the presence of eddy-current losses in the metallic magnetostrictive phase. Secondly, it may be difficult to machine and fabricate devices due to the mechanical brittleness of the ceramic and some metallic magnetostrictive phases as well as of the ceramic piezoelectric phase. Thirdly, it may be difficult to tailor and optimize the properties (i.e., magnetoelectric voltage coefficient α_E, etc.) of the devices due to the limitation of the types of the constituent materials. This invention provides a magnetoelectric element including at least one set of alternative piezoelectric layer and magnetostrictive composite layer. The magnetostrictive composite layer includes at least one magnetostrictive material dispersed in first concentrated zones within a first polymer matrix, wherein all of said concentrated zones are orientated along a first direction. It is found that the conversion efficiency (i.e., α_E) varies in accordance with applied magnetic control field H_control in magnetoelectric devices made of such a magnetoelectric element.

The invention belongs to the technical field of clocks and in particular discloses a charge pump circuit structure which is based on a standard complementary metal oxide semiconductor (CMOS) process, has low current mismatching and low current change and is applicable to a charge pump type phase locked loop. The charge pump circuit consists of a current biasing circuit, a reference current circuit, an output current circuit and an amplifier. A negative feedback loop is formed by utilizing the amplifier so as to reduce mismatching of charging current and discharging current due to the voltage change at an output end; and when the voltage at the output end changes, the total change of the charging current and the discharging current is reduced by adding current with a positive output voltage coefficient and current with a negative output voltage coefficient. The charge pump circuit can effectively reduce the mismatching of the charging current and the discharging current and the current change. Meanwhile, the circuit has high speed, low power consumption and low noise.

A ceramic dielectric composition suitable for preparing capacitors for use in high-temperature service conditions is disclosed. The ceramic material and capacitors made from it exhibit unique and heretofore unrealizable properties including low variation in capacitance with voltage up to high fields, low variation in capacitance with temperature over a broad temperature range, retained high permittivity at temperatures up to 200° C. and beyond, low loss, low field-induced strain and adequate capacitance to retain performance at very low service temperatures. The material is based on sodium bismuth titanate (NBT) with selected additions of substituents and dopants to broaden and flatten its dielectric response, lower loss, lower strain, lower voltage coefficient and increase resistivity.

The invention discloses surface electrode silver paste for a chip type resistor. The surface electrode silver paste is prepared from the following raw materials based on weight percentages: 65-74% of silver powder with grain diameter of smaller than 5[mu]m, 0.5-5% of palladium powder, 0.5-5% of metal powder, 1-6% of glass powder, and 10-33% of organic carrier. The invention also discloses a preparation method for the surface electrode silver paste for the chip type resistor. The surface electrode silver paste for the chip type resistor can effectively solve the problems on the aspects of adhesive force, electroplating property, acid resistance, printing property and the like; the main technological goals of the products comprise resistance value precision, working voltage, temperature coefficient, voltage coefficient, stability and the like, and technologic indexes of the like products in Europe and America can be reached; and all the adopted materials can satisfy environment protection demands of foreign countries.

The invention relates to a method for eliminating damage of hot marks by controlling an operating point with a constant voltage range of a photovoltaic module. The method comprises the following steps that an output end of the module is connected in series with an MPPT (Maximum Power Point Tracking) functional module and a DC-DC module sequentially; and the MPPT functional module searches the maximum power point of the module to track in a set operating voltage range. A method for setting the operating voltage range comprises the step of calculating an actual optimum operating voltage Vm when the module is not shielded by environment temperature Ta, irradiation strength R, a module temperature rise coefficient K caused by irradiation, a module temperature voltage coefficient Ct and a nominal rated optimal operating point voltage of the module at a temperature of 25 DEG C, which are obtained by measurement, according to a formula that Vm=Vmr-Ct(Ta+R*K-25), wherein the range of Vm+Vr to Vm-Vr is the set operating voltage range and Vr represents the maximum reverse bias voltage of the shielded module. In the method, the damage of the hot marks to the module can be eliminated in a mode of controlling the voltage of the operating point of the photovoltaic module. Meanwhile, in the mode, the design of the photovoltaic module without a bypass diode can be realized and the power loss caused by mismatching of electrical properties between the modules can also be reduced.

A method and apparatus for sensing the resistance state of data in a resistance memory cell by using the voltage coefficient of the cell instead of only its resistance. A voltage potential is applied across the resistance memory cell allowing the voltage coefficient of the cell to be determined and subsequently used to determine the logic state of the cell.

The present invention is an ultra-high voltage standard capacitor, which is an upright structure in which both the high-voltage electrode and the low-voltage electrode are fixed in the pressure vessel tank at the bottom with an insulating support, and overcomes the influence of the increase of the voltage level of the standard capacitor on the increase of its voltage coefficient. problem; for the field test structure, the present invention divides the standard capacitor into three independently sealed air chambers, which solves the inconvenient transportation problem of large-scale test equipment, so as to be used for field test and detection. When the present invention is used for UHV standard capacitors The insulation level is extremely high, the short-term power frequency voltage withstand capacity can exceed 1600kV, the long-term rated working voltage exceeds 1200kV, and the voltage coefficient is better than 2×10-6. The invention can also be used in the production of standard capacitors with a rated working voltage of less than 1600kV voltage level.

The present invention provides a method for adjusting a maximum power of a circuit having a first voltage output and a first power. The method includes the following steps: (a) obtaining a voltage coefficient by measuring the first power of the circuit and calculating an open-circuit voltage of the first voltage output; (b) estimating an estimated power based on the voltage coefficient; and (c) repeating the steps (a) to (b) for a specific number of times, in which the specific number of times is determined based on a variation of the estimated power during a time period.

The invention discloses a formation method of a silicon oxide film, comprising the following steps of: providing a substrate, placing the substrate into a film deposition chamber, vacuumizing the deposition chamber, heating the deposition chamber, introducing silicane and oxygenous gas to the deposition chamber, wherein the flow ratio of silicane to oxygenous gas is between 1:800 and 1:125, introducing energy to the deposition chamber to deposit the film, and taking out the substrate with the deposited film. The invention also discloses a corresponding formation method of a metal-insulator-metal capacitor. The metal-insulator-metal capacitor formed by using the silicon oxide film method reduces and stabilizes a voltage coefficient of capacitance and a temperature coefficient of capacitance of the capacitor, improves the dynamic characteristics of the capacitor and enhances the electrical property stability of the capacitor.

The invention relates to a circuit for measuring a voltage transformer voltage coefficient, and further relates to a method for measuring the voltage transformer voltage coefficient through the circuit. The circuit for measuring the voltage transformer voltage coefficient comprises a first single-stage voltage transformer (T1), a second single-stage voltage transformer (T2) and a passive linear circuit composed of an isolation transformer (T3). Both the rated transformation ratio of the first single-stage voltage transformer (T1) and the rated transformation ratio of the second single-stage voltage transformer (T2) are equal to K; the rated transformation ratio of the isolation transformer (T3) is equal to 1; a primary low-voltage terminal (X1) of the first single-stage voltage transformer (T1) is connected with a primary high-voltage terminal A2 of the second single-stage voltage transformer (T2); a secondary high-voltage terminal a1 of the first single-stage voltage transformer (T1) is connected with a primary high-voltage terminal A3 of the isolation transformer (T3); a secondary low-voltage terminal x1 of the first single-stage voltage transformer (T1) is connected with a primary low-voltage terminal X3 of the isolation transformer (T3); a secondary low-voltage terminal x3 of the isolation transformer (T3) is connected with a secondary high-voltage terminal a2 of the second single-stage voltage transformer (T2). According to the circuit and method for measuring the voltage transformer voltage coefficient, the effect of shielding errors of a voltage transformer on a series addition line can be overcome, and power frequency voltage addition can be effectively used in a 220 kV high-voltage interval and can even be used in a 330kV-1000kV extra-high-voltage interval.

The present invention discloses a least switching loss implementation method of a three-level inverter. According to the data of alternating current side voltage, the alternating current side current and the direct current side total voltage collected by a sensor and the region whether the current relation and the voltage vectors are located, a common-mode voltage coefficient k1 and a common-mode voltage coefficient k2 are selected, the equivalent modulation wave based on the maximum current phase modulation wave clamping is calculated, and the IGBT driving signals are generated through adoption of the double-triangle carrier comparison method. Through combination of the strategy of the maximum current phase modulation wave clamping and the double-triangle carrier comparison method, the least switching loss method is realized.

The invention discloses an on-chip oscillator circuit capable of eliminating control logic delay. The on-chip oscillator circuit mainly comprises a first reference voltage, a second reference voltage, a first charging and discharging current, a first charging and discharging switching group, a first charging and discharging capacitor, a first comparator and a control logic part, wherein the branch of the first charging and discharging capacitor is connected with a first switch tube in series, the first switch tube is in the open state, and the voltage of a starting signal and a power voltage are in positive correlation. According to the on-chip oscillator circuit capable of eliminating control logic delay, influences caused by control logic delay to a clock frequency voltage coefficient and a temperature coefficient can be eliminated, the circuit is especially suitable for the occasion with high clock frequency and big changes of a clock frequency range, the implementation cost is low, and the circuit is simple in structure and easy to implement.

The invention relates to a method for establishing a diffused resistor voltage coefficient extraction and simulation model. The method comprises the following steps of: manufacturing a plurality of testing resistors with the same length and different widths; placing all the testing resistors at the same temperature; scanning the testing resistors sequentially by using the same voltage; measuring the corresponding current values; calculating the resistance values of the testing resistors; extracting the voltage coefficients of the testing resistors with different widths one by one; segmentallyestablishing a plurality of resistor models; and corresponding to the plurality of resistor models by using one symbol. The method and a system for establishing the diffused resistor voltage coefficient extraction and simulation model are used for realizing that one symbol can correspond to the plurality of resistor models, and are convenient for designers to use the method and the system.

A series summation-calibrating device based on a semi-insulating voltage transformer includes a symmetrical high voltage test power supply, a three-port serial voltage transformer, a semi-insulating voltage transformer and an error measuring apparatus. The present invention is characterized by: a complete set of equipment for measuring the traceability of power frequency voltage ratio can be manufactured; calibrating the line according to the serial addition based on the semi-insulating voltage transformer; measuring the relative error between the three-port serial voltage transformer and the semi-insulating voltage transformer; and mathematically processing the measuring result to obtain the voltage coefficient curve of the semi-insulating voltage transformer error. The method is easy to operate without being restricted by voltage level, and can establish, from a low voltage of 10V to a high voltage of 1,000V, a standard power frequency voltage ratio measurement system serving as a measurement standard at the national or provincial/ministerial level.

Integrated circuits and manufacturing methods are presented for creating diffusion resistors (101, 103) in which the diffusion resistor well is spaced from oppositely doped wells to mitigate diffusion resistor well depletion under high biasing so as to provide reduced voltage coefficient of resistivity and increased breakdown voltage for high-voltage applications.

The invention provides a stand-off ratio voltage coefficient detection method based on a separable direct current voltage divider. The method comprises the steps of 1, measuring the relative error of the voltage of a low-voltage arm resistor of a direct current voltage divider to be measured with a first auxiliary voltage divider as the reference standard; 2, measuring the relative error of the voltage of the low-voltage arm resistor of the direct current voltage divider to be measured with a second auxiliary voltage divider as the reference standard; 3, measuring the relative error of the voltage of the low-voltage arm resistor of the direct current voltage divider to be measured with a voltage divider subcircuit formed by series connection of the first auxiliary voltage divider and the second auxiliary voltage divider as the reference standard; 4, calculating the stand-off ratio voltage coefficient of the direct current voltage divider to be measured. Compared with the prior art, the method has the advantages that detection is easier and more convenient, a detection result is more accurate, and the influence of the difference in low-voltage arm resistors of auxiliary voltage dividers on calculation of the stand-off ratio voltage coefficient of the direct current voltage divider to be measured existing during a direct voltage addition test is avoided.

The invention provides a standard capacitor installed by a separated type coaxial structure. The standard capacitor is characterized in that the standard capacitor comprises a bottom plate, a casing component, an electrode component, a high voltage bushing, a conducting rod and a grading ring, the electrode component comprises an electrode fixing platform, a supporting insulator, a high voltage electrode, a low voltage electrode and a shield component, the casing component and the electrode fixing platform are installed at the center of the bottom plate, the low voltage electrode and shield component are fixed on a flange of the electrode fixing platform, the supporting insulator is disposed at the center of a base plate of the electrode fixing platform, the high voltage electrode is mounted at the center of the supporting insulator, and the high voltage bushing is installed at the center of the casing component. According to the standard capacitor installed by the separated type coaxial structure, the separated type structure is utilized, the low voltage electrode and the shield component are separated from a barrel wall, the change of capacitance caused by the deformation of the barrel wall is avoided, temperature coefficient and pressure coefficient are reduced, simultaneously, each part on the installing platform is positioned and processed along a central axis, the coaxiality of high and low voltage electrode assembly can be effectively guaranteed, and the voltage coefficient is reduced.

The invention provides a differential amplification circuit and an assembly line ADC with the differential amplification circuit. The differential amplification circuit comprises super-source followers, output voltage of each super-source follower is strictly equivalent to input voltage of the same, low output resistance can be realized, the capability that the output voltage follows the input voltage is improved, the output voltage is converted into current via resistors, the voltage and temperature coefficients of theresistors are both very low, namely, the linearity of theresistors is higher, and thus, the linearity of the differential amplification circuit is improved.