42results about How to "The resistance value is accurate" patented technology

The invention relates to a wafer resistance element and a preparation method thereof; wherein, the wafer resistance element comprises a substrate, two positive electrodes which are arranged on the frontal surface of the substrate, two back electrodes which are arranged on the back surface of the substrate, a resistance layer which is arranged between the two back electrodes and provided with prearranged resistance, a protection film which coats the resistance layer and is isolated from the environment, two side electrodes which are respectively arranged on two side surfaces of the substrate and are electrically connected with the positive electrodes and the back electrodes at the same side respectively, and two layers of coatings which form three layers of coats from above the surfaces of the positive electrodes, the side electrodes and the back electrodes at the same side and comprise the main compositions of copper, nickel and tin. The invention also provides the method used for preparing the wafer resistance element. The wafer resistance element and the preparation method thereof take the copper, the nickel and the tin as main materials to form the coatings with simple preparation process, lead the element to be easily and correctly positioned on a soldering pad by liquid solder tin and to be bonded with the solder tin into a whole excellently, reduce the electron circulation path from the element to the soldering pad, and lead the element to have large power application and to provide precise micro-resistance values.

The invention relates to a performance detection and analysis method for a gas turbine air intake filter. The method comprises the steps of S1 data collection and S2 intake air filter resistance correcting. According to the step S1, the air pressure of each air intake filter at an air intake filter air inlet in a number of periods of time are simultaneously measured to acquire a first air pressure value; the air pressure of a filter air outlet is simultaneously measured to acquire a second air pressure value; and the air flow of the filter air outlet is simultaneously measured to acquire the air flow value at each time point in different periods of time. According to the step S2, the resistance of the air intake filter is corrected based on the measured first air pressure value, the second air pressure value and the air flow value to acquire the corrected resistance of the filter. The method can be used to effectively select a required gas turbine air intake filter.

The invention provides an antenna and an adjusting device for the electrical downtilt of the antenna. The adjusting device comprises an electric tuning unit, a first transmission mechanism, a pull rod, a second transmission mechanism, a potentiometer and a phase shifter, wherein the first transmission mechanism is respectively and mechanically connected with the electric tuning unit and the pull rod for converting rotary movement output by the electric tuning unit into linear movement of the pull rod, the second transmission mechanism is respectively and mechanically connected with the pull rod and the phase shifter for transmitting the linear movement of the pull rod to the phase shifter, the potentiometer is directly and mechanically connected with the pull rod, and is also electrically connected with the electric tuning unit for enabling the electric tuning unit to receive a resistance value measured by the potentiometer and to adjust the rotating angle of the electric tuning unit according to the relationship between the resistance value and the electrical downtilt of the antenna. Through the above manner, adjustment for the electrical downtilt of the antenna can be realized by the adjusting device with a simpler structure, the cost is relatively low, the transmission error during adjustment can be reduced, and the adjusting precision of the electrical downtilt of the antenna is improved.

The invention discloses a semiconductor testing circuit and a method for detecting conductive properties of a tested piece. The semiconductor testing circuit comprises the tested piece, a resistor, a first signal-applying welding pad, a first test welding pad, a second signal-applying welding pad and a second test welding pad, wherein the tested piece is connected with a switch in series; the resistor is parallelly connected with a series circuit of the tested piece and the switch; the first signal-applying welding pad and the first test welding pad are connected to one end of the parallel circuit; the second signal-applying welding pad and the second test welding pad are connected to the other end of the parallel circuit; and the first signal-applying welding pad, the first test welding pad, the second signal-applying welding pad and the second test welding pad form four ends of a Kelvin Contact. When in test, the switch is switched off firstly, the Kelvin Contact is adopted to obtain a resistance value of the additionally arranged resistor, then the switch is switched on, the Kelvin Contact is further adopted to obtain a total resistance value of the tested piece and the additionally arranged resistor after parallel connection, and the resistance value of the tested piece can be obtained accurately by separating the resistance value of the additionally arranged resistor from the total resistance value.

A mass pruduction method for manufacturing chip resistors includes a solid pressing and bonding step, a resistor body defining step, a resistor forming step, an electrode forming step and a finished product obtaining step. In the solid pressing and bonding step, a first sheet and a second sheet are connected by an isolation material with high thermal conductivity. In the resistor body defining step, vertical penetrating slots and transverse penetrating slots are formed to define resistor blocks arranged by order arrays. In the resistor forming step, slits and at least one dividing penetrating groove are formed in each resistor block to enable the resistor blocks to be molded into resistor semi-finished products. In the electrode forming step, a conductor material is utilized to make each resistor semi-finished product form two electrodes that connects with resistor bodies. In the finished product obtaining step, the resistor bodies with electrodes are punched and trimmed to form multiple chip resistors.

The invention discloses a read-out circuit and a working method thereof, relating to a read-out circuit and a working method thereof. The read-out circuit comprises M columns*N rows of pixel circuits,N rows of row level test resistance circuits, M columns of column level test resistance circuits and M columns of column level read-out circuits, wherein both M and N are natural numbers, M is greater than or equal to 2, and N is greater than or equal to 2, the row level test resistance circuits, the column level test resistance circuits and the columns level read-out circuits are all connected with the pixel circuits, the column level test resistance circuits are connected with the column level read-out circuits, the column level read-out circuits comprise test column secondary circuits, andthe column level read-out circuits are further connected with a current source. Functions of all columns and rows of the whole read-out circuit can be tested without an MEMS sensor, further, more accurate MEMS resistance can be acquired when the MEMS sensor is available, the test result is more accurate, and the test efficiency is improved.

The invention discloses a method for checking the welding quality of a stator winding joint of a large power generator, comprising the following steps: 1) outputting constant 50A direct current by virtue of a 50A transformer direct-current resistance tester so as to be connected with the two ends of the stator winding joint; 2) utilizing a 0.2A-level current divider for measuring current and a direct-current voltmeter to monitor a direct-current value; and 3) measuring the voltages at the two ends of a joint resistor by using a high-accuracy digital multimeter, and converting the voltages into a resistance value. By utilizing the method, the measuring accuracy of the resistance value of the stator winding joint can reach 0.2mu Omega. According to the method disclosed by the invention, the voltages of the two ends of the joint resistor are measured by the high-accuracy digital multimeter so as to improve the accuracy, so that not only can large current be guaranteed, but also the high accuracy is met. The invention provides a method for measuring a resistance value of the welding joint simply, conveniently and accurately, so that the accuracy of the welding joint of a measured winding can be guaranteed, and an accurate resistance value is provided for the welding quality of a bar joint so as to handle the unqualified welding joint in time.

A voltage monitor having a bandgap reference circuit driven by a voltage to be monitored. The bandgap reference circuit produces a voltage and a second voltage that each vary with the voltage to be monitored. The magnitudes of these voltages are compared by an open loop comparator to provide a high speed output state. The output of the voltage monitor can be used to monitor a supply voltage and produce a reset signal to a processor if the supply voltage falls to a magnitude below a specified threshold.

The invention discloses a lithium battery electrode plate welding resistance testing device and method, and the front end of a testing clamp is provided with a cambered surface, thereby guaranteeing that a battery electrode plate is inserted into the middle of the testing clamp without any obstacle when the battery electrode plate is contacted, and avoiding the damage to the battery electrode plate. A lithium battery positioning hole is formed in the working table, so that errors in measurement due to the fact that the lithium battery is not placed in place can be prevented; according to the test method, the problems of power cables, contact resistance, non-repetitive measurement points and the like are eliminated, and the resistance value of the weld joint of the battery electrode plate can be reflected more accurately; instruments capable of directly measuring resistance on the market are all handheld, the measurement precision can only reach the milliohm level, double electrodes areused for measurement at the same time, each lithium battery is provided with a cathode and an anode, each electrode is formed by welding two electrode plates, the device can measure the cathode and the anode at the same time, and the measurement efficiency is doubled.

The invention provides a drag calculation method for fluid equipment on the basis of CFD (Computational Fluid Dynamics). The method comprises the following steps that: S1: dividing the fluid equipmentinto a plurality of areas of which the flowing are relatively independent; S2: independently dividing a grid for each area; S3: on the basis of the grid of each area, through the CFD software, carrying out CFD analysis to obtain one group of flow-drag data; S4: utilizing quadratic fitting to obtain the curves of the traffic and the drag of each area; S5: simplifying the plurality of areas of which the flowing are relatively independent into a plurality of models with an constant circulation sectional area; S6: dividing the grid for a simplified geometric model, in the CFD software, adding a drag source item to each model with the constant circulation sectional area on the basis of a fitting coefficient obtained by the quadratic fitting; and S7: on the basis of the grid of the simplified geometric model, through the CFD software, carrying out CFD analysis to obtain the preliminary drag value of the fluid equipment. By use of the drag calculation method, the consumption of manual resources and computer resources can be lowered, and calculation accuracy can be improved.

The invention relates to a well resistor structure, including an insulating layer and an active region on the insulating layer. The active region includes a well region, and also includes a trench isolation structure extending downwards to the insulating layer, and the trench isolation structure surrounds the well region in a transverse direction and separates the well region in a vertical direction; and the well resistor structure also includes a metal contact which is arranged on the well region and is in contact with the well region. The invention also relates to a manufacturing method of the well resistor structure and a silicon device on an insulator. According to the well resistor structure provided by the invention, the trench isolation structure is formed in the active region, so that the well region is blocked by the trench isolation structure in the transverse direction, transverse diffusion of majority carriers is not formed, and thus well resistance with a relatively accurate resistance value can be obtained.

The invention relates to a charge-controlled intelligent ammeter capable of detecting faults of built-in switches. The charge-controlled intelligent ammeter comprises a first current transformer, a second current transformer, a first switch, a second switch, a third switch, a first resistor, a second resistor, a first voltage collection unit, a second voltage collection unit, a third voltage collection unit, a fourth voltage collection unit, a DSP, an A / D converter, a temperature sensor, a control unit and a display. According to the charge-controlled intelligent ammeter, an accurate resistance value is acquired by detecting the fluctuation of voltages at two ends of the built-in switches and flow currents at different moments, and the automatic detection of the faults of the built-in switches is realized; the on-off states of the three built-in switches are controlled through the DSP according to charge balance information of an electric user, and the reliable charge control is realized; and the fluctuation of voltages at two ends of the built-in switches and the flow currents at different moments are detected, a compensation factor of each voltage collection unit is modified in real time, and the accurate resistance value is obtained, so that the automatic detection of the faults of the built-in switches is realized.

The invention discloses a potentiometer which comprises a housing, a rotating shaft, a brush and the like, wherein a brush sliding region is arranged on the housing; the brush sliding region comprises a brush non-conducting region, a brush conduction waiting region and a brush conducting variable-resistance region from a starting point to an end point; the brush is driven by the rotating shaft to be in sliding contact with a brush contact region; a power supply end and a position signal end are respectively connected between the brush and the brush sliding region. The potentiometer does not produce current within a certain angle range behind the starting point position, to avoid that the potentiometer keeps consuming current when the potentiometer does not return to the starting point at gap operation; the brush is conducted and converted from infinite resistance to zero, which is beneficial for the identification of product signal output; the potentiometer has relatively good accuracy, is widely applied, and is beneficial for popularization and use of products. The invention further discloses a combination device of the potentiometer and a cooker ignition switch, wherein the combination device is simple in structure and easy to operate, and is beneficial for accurately outputting a firepower regulating signal of the cooker ignition switch.

The invention relates to a railway signal cable insulation low-voltage rapid online testing device and a railway signal cable insulation low-voltage rapid online testing method. The railway signal cable insulation low-voltage rapid online testing device is used for quickly and precisely measuring insulation resistance of a railway signal cable at low voltage, is connected with an external to-be-tested cable and an external insulation leakage current testing device, and comprises a signal sampling and filtering circuit, an ADC chip and communication isolation circuit, a main MCU circuit and a communication circuit, wherein the signal sampling and filtering circuit is connected with the external to-be-tested cable and is used for acquiring data of the external to-be-tested cable; the ADC chip and communication isolation circuit is connected with the signal sampling and filtering circuit, and is used for converting an analog signal adopted by the signal sampling and filtering circuit intoa digital signal and outputting the digital signal; the main MCU circuit is respectively connected with the signal sampling and filtering circuit and the ADC chip and communication isolation circuit;and the communication circuit is respectively connected with the main MCU circuit and the external insulation leakage current testing device. Compared with the prior art, the railway signal cable insulation low-voltage rapid online testing device has the advantages of low output voltage, short measurement time, high precision and the like.

The invention discloses an aluminum nitride ceramic substrate 100 W-6 dB attenuation slice. The attenuation slice comprises an 8.9 mm*5.7 mm*1 mm aluminum nitride ceramic substrate. A silver paste conductor layer is printed on the back surface of the aluminum nitride ceramic substrate, silver paste wires are printed on the front surface of the aluminum nitride ceramic substrate, the two ends of each silver paste wire are respectively connected with a bonding pad, resistors are printed among the silver paste wires, high-temperature protection films are printed on the resistors, and acid and alkali-resistant protection films are printed on the silver paste wires and the high-temperature protection films. According to the attenuation slice, in the design thought, the circuit structure of the output end is optimized, standing waves of the output end are improved, and the inductance-capacitance performance of circuits is adjusted. Meanwhile, by accurate modification of the resistance value, the high-accuracy attenuation value is obtained. Various indexes of the aluminum nitride ceramic substrate 100 W-6 dB attenuation slice are good, and therefore the aluminum nitride ceramic substrate 100 W-6 dB attenuation slice meets the use requirements of present 4G networks.

Provided are: a copper alloy material for a resistance member having favorable laser weldability, said copper alloy material being capable of easily obtaining a correct measured value in the measurement of electrical resistivity; and a method for manufacturing the copper alloy material. The copper alloy material for a resistance member is a rolled sheet having a thickness t of 0.04 mm or more whenmeasured using a contact-type film thickness gauge, and the copper alloy material comprises 2-14 mass% of manganese with the remainder comprising copper and unavoidable impurities. Further, when theroughness curve in a direction orthogonal to the rolling direction is acquired using a contact-type surface roughness measurement technique, the sheet surface of the rolled sheet has a maximum heightRz of 0.3-1.5 mu m, an average length of roughness curve elements RSm of 0.03-0.15 mm, and a value of a parameter A of 0.002-0.04.

The invention relates to a conductive contact finger and a wiring board using the conductive contact finger, comprising a contact surface and a side face opposite to a circumferentially adjacent conductive contact finger, at least one of the two opposite side faces is provided with a convex There are supporting convex parts used to cooperate with the side supports of adjacent conductive contact fingers to maintain the rotation gap between the conductive contact fingers. The present invention adopts the support convex part provided on the side of each conductive contact finger, which can ensure the rotation gap of the adjacent conductive contact fingers in the circumferential direction, so that each conductive contact finger has enough rotation gap to rotate and contact with the conductive rod and the wiring board. Uniform and good contact, accurate resistance value, avoiding damage to corresponding contact parts due to excessive local current.

The invention relates to resistor detection methods and devices of a battery, a charge / discharge control method and device of the battery, and electronic equipment. One resistor detection method of the battery comprises the following steps: controlling the battery to stop a charge / discharge operation when detecting the resistor of the battery, or performing the charge / discharge operation in a current value less than a threshold; and acquiring a resistance value of an identity (ID) resistor and a resistance value of a negative temperature coefficient (NTC) resistor. Through the above technicalscheme, the additional voltage produced by loop impedance of a common circuit is reduced, so that the resistance value of the ID resistor and the resistance value of the NTC resistor are more accurate, and the accuracy rate of identifying the battery identity and the temperature are improved.

The invention provides a method for calculating the number of through holes of a cross-layer chain type connecting structure. The method comprises the steps of dividing a connecting line into a plurality of structural blocks connected in sequence; identifying a skip layer structure block in the Mi layer, and identifying an overlapping region of the structure block or pin of the adjacent layer andthe skip layer structure block; and identifying the through holes in the overlapping region, and calculating the total number of the through holes according to the number of the through holes. The invention further provides a corresponding method for calculating the resistance value, and a formula is utilized. And omission and repeated calculation are avoided, errors can be effectively reduced, and then the accurate resistance value of the cross-layer chain type connection structure is obtained through calculation so as to guide selection of a test range. The steps are simple, the result is accurate, and improvement and optimization of the production process are facilitated.

The invention relates to a performance detection and analysis method for a gas turbine air intake filter. The method comprises the steps of S1 data collection and S2 intake air filter resistance correcting. According to the step S1, the air pressure of each air intake filter at an air intake filter air inlet in a number of periods of time are simultaneously measured to acquire a first air pressure value; the air pressure of a filter air outlet is simultaneously measured to acquire a second air pressure value; and the air flow of the filter air outlet is simultaneously measured to acquire the air flow value at each time point in different periods of time. According to the step S2, the resistance of the air intake filter is corrected based on the measured first air pressure value, the second air pressure value and the air flow value to acquire the corrected resistance of the filter. The method can be used to effectively select a required gas turbine air intake filter.

The invention relates to a high-voltage withstanding PNP-type anti-backflow power driver and a manufacturing method thereof. The power driver comprises a PNP transistor and a pull-up resistor, whereinone end of the pull-up resistor is connected with the emitter of the PNP transistor and the other end is connected with the base of the PNP transistor, and thus, potential pull up of the base is realized; and the emitter of the PNP transistor is used as an input end of the power driver. The power driver also comprises an anti-backflow diode, the anode of the anti-backflow diode is connected withthe collector of the PNP transistor, and the cathode of the anti-backflow diode is used as an output end of the power driver. Compared with the prior art, the power driver provided in the invention has the advantages of simple structure, simple and convenient manufacturing process, good performance and low cost.

The invention discloses a resistance device capable of wirelessly controlling resistance for a bicycle training table. The resistance device comprises a magnetic resistance mechanism for generating resistance, an executing mechanism for adjusting the resistance, a transmission mechanism and a plastic part for supporting and protecting. The magnetic resistance mechanism comprises an aluminum magnetic disk resistance piece and a magnet, the resistance adjusting executing mechanism is controlled by a motor, the magnet is dragged through a lead screw to do linear motion relative to the magnetic disk resistance piece, the magnetic flux of the magnet passing through the magnetic disk resistance piece is changed, the magnetic disk resistance piece rotates to cut magnetic lines, and resistance acting on the transmission mechanism is correspondingly changed. A motor of the actuating mechanism is controlled by a built-in circuit board, a built-in battery supplies power to the motor and the circuit board, a remote controller or a mobile phone APP is used for sending an instruction to an actuator through signal wireless transmission, and therefore wireless control over the resistance is achieved. The action of the motor actuating mechanism is more accurate, the resistance value of each gear is more accurate, and meanwhile, a foundation is laid for subsequent intelligent upgrading.

The invention discloses a USB interface load testing device, comprising a USB interface, the USB interface is connected with a detector, the detector is composed of a current detector and a voltage detector, and the current detector is directly connected with a variable resistor , a voltage detector is connected in parallel on the variable resistor, the current detector and the voltage detector are connected with a data converter, and an electric signal amplifier is also installed on the data converter, and the electric signal amplifier is connected with a single-chip microcomputer, The single-chip microcomputer is connected with a display, has strong compatibility, can actively adapt to USB interfaces with different load values, and has a more accurate resistance value, which can better adapt to the measured object, making the measurement more accurate, with small errors, and directly transfers the measured mechanical signal It is converted into an electrical signal, and after being amplified, it is processed by a single-chip microcomputer to directly give the load capacity of the USB interface, which is more convenient, and the added safety capacitor and protective resistor are more safe and efficient.