368 results about "Impedance testing" patented technology

In one embodiment, the present invention includes a test signal generator capable of producing an impedance test signal comprising of a sine wave having a known frequency. The test signal generator may include a crystal oscillator, a counter, and a lookup table. The lookup table output is applied to a digital to analog converter and is then low pass filtered using a conventional analog filter to produce a sine wave of a known frequency and voltage amplitude. The test signal flows through the electrode and combines with an electrophysiological signal to form a combined signal. A signal processor is used to isolate the combined signal into the test signal component and the electrophysiological component. The signal processor digitally low pass filters the combined signal and the output of the low pass filter is the electrophysiological signal. The signal processor then digitally bandpass filters the combined signal using a filter with a center frequency which is the same as the test frequency. The output of this filter is then used to calculate the electrode impedance.

A battery charge control system including an algorithm for determining whether the battery chemistry of a battery pack for use in a portable electronic device is primary, in which case charging is prevented, or secondary, in which case charging is enabled. The routine operates by measuring the terminal voltage and temperature of the battery under certain predetermined tests, which generally include a combination of voltage and internal impedance tests performed during charge or discharge. Additionally, a method is described to detect and to correct for lack of cell balance within the rechargeable battery pack of a portable electronic device. A cell or cells of the battery pack which are close to depletion, or are completely depleted, are detected, and a discharge/charge routine is executed to provide for optimum recharging of all of the cells of the battery, thus ensuring proper cell balance, and most efficient power usage.

The invention discloses a three-electrode measurement based online monitoring method for electrochemical properties of a positive electrode and a negative electrode of a lithium battery. The method is characterized by comprising steps of 1, selecting appropriate material for assembling a three-electrode measurement device; 2, adopting a charge/discharge testing instrument to connect with the positive electrode and the negative electrode of a three-electrode lithium ion battery separately and performing charge/discharge testing; 3, performing online synchronous monitoring on positive voltage and negative voltage of the lithium ion battery; 4, performing online synchronous electrochemical impedance testing on the lithium ion battery and utilizing an impedance spectroscopy testing instrument to measure the positive electrode and the negative electrode and the electrochemical impedance spectroscopy of the whole battery after the battery is charged or discharged until a stable state is reached. The invention has beneficial effects that the novel testing method capable of collecting electrochemical information of the whole battery, the positive electrode and the negative electrode at the same time is provided and a defect that electrochemical information in the battery cannot be measured accurately by using a current traditional two-electrode testing method for commercial batteries is made up.

The invention relates to a life prediction method based on a lithium-ion battery aging model. The method comprises the steps that (1) the capacity retention ratio of a lithium battery in a 50% SOC state after storage suspension under different temperature and the value, which changes along with storage time, of direct-current internal resistance of the battery are tested; (2) the battery in different voltage states is stored for the same time under the same temperature, and alternating-current impedance testing and direct-current internal resistance testing are performed; (3) the correlation between calendar life capacity attenuation, alternating-current internal resistance changing and direct-current internal resistance changing and temperature and voltage is analyzed, and the changing process of experimental aging data over time is described through a fitting function; and (4) the model is analyzed according to fitted data, measured effective data is fitted, and battery calendar lifeand battery internal resistance parameters in the future are effectively predicted. Through the method, a truthful life state can be inferred from an accelerated aging test, the test method is simple, advanced equipment and complicated operation are not needed, and the test cycle is greatly shortened.

The invention discloses a lithium-ion power battery health state evaluating system and method. The system comprises an MCU central control module, a voltage and current detecting module, a GPES and FRA detecting module, a display module and a battery module with a lithium-ion power battery. According to the method, voltage changes after the lithium-ion power battery discharges and is cut off are recorded so as to obtain voltage recovery rate and further obtain a main factor judgment value through the voltage recovery rate; alternating-current impedance testing is conducted on the lithium-ion power battery so as to obtain alternating-current impedance spectra, fitting is conducted on the alternating-current impedance spectra to obtain an equivalent circuit diagram, the interior impedance of the lithium-ion power battery is worked out according to impedances of all parts inside the lithium-ion power battery, a secondary factor judgment value is obtained through the interior impedance, the state of health (SOH) value of the lithium-ion power battery is the total of the main factor judgment value and the secondary factor judgment value, and therefore calculation result is more accurate.

An internal impedance measurement system of switch power-supply EMI noise source based on Hibert transform and current probe comprises line-impedance stable network, common mode/difference mode impedance test module, signal generator and frequency spectrum analyzer. It is featured as inputting power supply wire directly to impedance stable network then inputting to switch power supply and load for forming a complete power supply loop through common mode/different mode impedance test module. The method for measuring said internal impedance is also disclosed.

The invention discloses a portable lightning current generating device and method for grounding device impact impedance testing. The device comprises a power generator and a lightning current generator main loop test box. A rectifying silicon stack D, a charging resistor R1 and a direct-current voltage divider are connected in series to the output end of a boosting transformer T2. An energy-storage capacitor C is connected in parallel to the direct-current voltage divider. One end of a discharging switch S is connected with a positive electrode of the energy-storage capacitor C. The other end of the discharging switch S is connected with an adjustable wave modulated resistor R2. The other end of the adjustable wave modulated resistor R2 is connected with one end of an adjustable wave modulated inductor L. The other end of the adjustable wave modulated inductor L is connected with a grounding grid to be tested through a grounding testing current injection point. A grounding testing reverse current electrode and a reference voltage electrode are arranged on the periphery of the grounding grid to be tested. The ground testing reverse current electrode is connected to a negative electrode of the energy-storage capacitor C of a lightning current generator main loop. The device can simulate inductive effect and soil spark discharging effect really, and impact grounding resistance can be tested really.

The invention provides a novel realization method for testing thyristor-grade impedance. According to the method, the testing reliability, the testing precision and the testing efficiency can be improved effectively. By adopting the testing system, the direct-current voltage, and the alternating-current voltages of 100Hz and 10kHz are acted on the thyristor-grade sample; subsequently the thyristor-grade voltage and thyristor-grade current can be measured; the impedance is calculated; and the testing result can be transmitted to a controlling and displaying system by a CAN bus, thus facilitating the judgment on the testing results.

The invention provides a lithium ion battery failure analysis method based on an alternating current impedance method. The safety performance of a lithium-ion battery has attracted much attention, anda negative electrode of the lithium ion battery is easily subjected to lithium evolution under the abuse condition, so that a lithium dendritic crystal is formed, and thermal runaway or even explosion of the battery is caused. According to the lithium ion battery failure analysis method based on the alternating current impedance method provided by the invention, an electrochemical alternating current impedance testing method is adopted, a relationship between an alternating current impedance spectrum signal and the internal environment of the battery is analyzed, the SEI film resistance change can be analyzed from an alternating current impedance spectrum, and therefore the state of short circuit in the dendritic crystal of the battery can be quickly and accurately predicted without damaging the battery, thereby evaluating the service life and the safety of the battery.

A flat high definition multimedia interface (HDMI) cable. The flat cable that is less visible in comparison to a round HDMI cable for wall mounted television setup. An HDMI connector is coupled to the flat cable. An active circuit isolates physical characteristics of the HDMI connector. The active circuit causes the flat cable to appear shorter than its actual length during HDMI compliance testing using impedance testing. Moreover, the active circuit causes a consumer electronic control (CEC) line, a display data channel (DDC) line and transition minimized differential signal (TMDS) line to actively terminate for reducing parasitic capacitance from the length of the flat cable during HDMI compliance testing. Thus, the isolation allows the flat cable to satisfy HDMI compliant testing. The flat cable may be selected from a group consisting of ribbon cable, twisted pair cable, flexible printed circuit board, micro coax cable, optical cable and glass fiber cable.

The invention relates to a battery health state detection method which includes the steps: firstly, measuring the alternating-current impedance of an unused new battery by the aid of an alternating-current impedance meter to obtain the internal resistance of the new battery; secondly, obtaining a used old end-of-life battery and measuring the alternating-current impedance of the old battery by the aid of the alternating-current impedance meter to obtain the internal resistance of the old battery; thirdly, measuring the alternating-current impedance of a battery to be measured by the aid of the alternating-current impedance meter to obtain the current internal resistance of the battery to be measured; fourthly, calculating the health degree of the battery to be measured according to the internal resistance of the new battery, the internal resistance of the old battery and the current internal resistance of the battery to be measured, and further judging the health state of the battery according to the health degree. An alternating-current impedance testing method is simple, short time is consumed, and online testing can be realized. Besides, change of ohmic resistance represents attenuation of battery capacity, and the ohmic resistance and the battery capacity have a corresponding relationship, so that accuracy of the health state of the battery estimated by the method is high.

The invention discloses a method for establishing the corresponding relationship between the transformer winding deformation fault and sweep frequency impedance characteristic. The method comprises the following steps: establishing an equivalent circuit model for a transformer winding; performing circuit parameter fault simulation; carrying out the sweep frequency impedance testing and simulating of a winding deformation fault; using the correlation coefficient method to calculate the relevant coefficients before and after the changes of the sweep frequency impedance curve; using the three-dimensional finite element method to calculate the electric parameters at the winding deformation state; and through the comparison and analysis of the above two, obtaining the corresponding relationship between the electric parameter change and the type of the transformer winding deformation fault. Compared with the prior art, the method of the invention can establish the corresponding relationship between the winding deformation and the sweep frequency impedance change characteristic directly and quantitatively so that deep explanation is possible for the sweep frequency impedance characteristic curve, that the transformer winding deformation diagnosing precision is increased, and that the large amount of human labor, material and financial devotion of the oil extraction hanging hood are reduced when the transformer is subject to offline maintenance.

The invention discloses a measurement device for detecting the porosity of saturated soil and an application method of the device. The measurement device comprises a cutting ring, a stainless steel electrode, a cutting ring, an organic glass box and an impedance tester. When the impedance of a soil sample is measured, the cutting ring is selected according to the property of the soil sample; the stainless steel electrode is connected with the impedance tester through a connecting wire; when the impedance of pore water is measured, the organic glass box is selected and the stainless steel electrode is connected with the impedance tester through the connecting wire; and a frequency selector and an electric level adjuster are connected with a computer through the impedance tester. The device disclosed by the invention can be used for collecting the soil sample, preparing the saturated soil sample, setting electric signal frequency and impedance testing voltage and determining the resistivity of the saturated soil and pore water; and soil properties and cementation factors are selected according to the property of the soil sample and the porosity is obtained by the computer. The measurement device disclosed by the invention has the characteristics of simplicity and feasibility, low cost, short measurement period, accurate result and the like; expensive equipment is not needed and an operation method is simple; and the measurement device can be operated in a laboratory or a filed and the practical applicability is very high.

The invention provides an impedance test device of a low-voltage electric power carrier channel, belonging to the power grid carrier communication field, which solves the problems of the existing method for measuring carrier channel impedance that the frequency characteristics of a high-frequency transformer and a resonant circuit affect the accuracy of the measuring value of a carrier, only the impedance modulus can be measured but the impedance phase can not be measured owing to limited carrier measuring frequency points. In the invention, a starting carrier control terminal of an embedded signal acquisition and processing system is connected with a signal control terminal of a DDS (direct digital synthesis) carrier signal source, testing input-output terminals of the embedded signal acquisition and processing system are connected with testing input-output terminals of a free coordinate axis vector test unit; the DDS carrier signal source, a high-frequency power amplifier and a primary side of a high-frequency transformer are sequentially connected; a load resistor R is connected in series between the high-frequency power amplifier and the primary side of the high-frequency transformer; a secondary side output terminal of the high-frequency transformer is connected with an input terminal of a coupling unit of a detuned circuit; and an output terminal of the coupling unit of the detuned circuit is connected with two tested low-voltage power lines.

The invention discloses a wearable noninvasive dynamic blood glucose monitor based on photo-acoustic spectrometry features and relates to the field of blood glucose level detection in order to solve the technical problems that an existing noninvasive glucometer is single in detection structure, necessary measurement compensation and correction lack, work precision of the existing noninvasive glucometer is greatly affected by the environment when there is individual difference, and the deviation between a real blood glucose value and a measured value is large. Besides, the existing glucometer has the technical problems of being inconvenient to carry, low in stability, poor in universality and the like. The wearable noninvasive dynamic blood glucose monitor mainly structurally comprises a multi-wavelength tunable fiber laser, a microprocessor, a display module, an impedance testing unit, a temperature sensor, a photoacoustic cavity, an optical substrate and transparent colloid. The blood glucose monitor is used for improving detection precision, can also be used for detecting impedance, temperature and other signals, corrects data, and avoids influences of the surrounding environment.

The invention discloses a system and a method which can rapidly test the characteristic impedance of a printed circuit board. The system comprises a test host, a probe, a PC machine, a printer and analysis software which is operated on the PC machine. The test host comprises a pulse generating circuit, a pulse receiving circuit, a coaxial switch, a signal acquisition module, a logic control module and a CPU processing module. The system adopts the intelligent and automatic design, a user can automatically test, display the result, and the like, by only carrying out the simple initialization settings through the combination with the test method, thereby simplifying the manual operation steps and reducing the operation difficulty. An output end in the system adopts the coaxial switch to carry out the switch, the differential impedance test can be realized by using the single step pulse transmission and a single receiving channel, thereby avoiding the error problem caused by adopting two step pulse generating circuits or two receiving channels which are not fully consistent, effectively improve the test precision and simultaneously reducing the probability of damaging the test host by the external static electricity.

The invention relates to a device for searching fault points of a cable or a pipeline. The device for searching fault points of the cable or the pipeline comprises a transmitter and a receiver, wherein the transmitter is composed of a control system, a signal producing circuit, a signal amplification circuit, a gear shifting circuit or a voltage limiting circuit for alternating current or direct current output, a power detection circuit, a power regulating circuit, a impedance measurement circuit, an analogue/ digital (A/D) sampling circuit, a keyboard and a display device. The device for searching fault points of the cable or the pipeline comprises four detection circuiting methods: low-frequency alternating current detection method, high-frequency alternating current detection method, pulse detection method and impedance detection method. The four detection methods are used and provide evidence for each other, and thus fault points are determined reliably. When the cable or the pipeline is detected, cable or pipeline condition changes, cable line-breaking fault condition, cable insulation condition relative to the ground and the like are considered, and then fault points are found out.

The invention relates to a radio frequency identification electronic label antenna complex impedance test device and a method. A cable is respectively and electrically connected with a vector network analyzer and a second metal plate, the second metal plate is embedded inside a first metal plate, a core of a switching port is electrically connected with a feed port of a semi-arm electronic label antenna, and a sheath of the switching port is connected with the second metal plate in a short-circuit way. By utilizing the principle of an image method and testing the impedance of the semi-arm antenna port, the test difficulty for the balance feed-form antenna can be solved. Compared with the steps of a balance/imbalance converter and a matching network required for testing the balance feed-form antenna impedance, the test procedure of the device is simple and convenient, and the device has economic benefit while ensuring the test precision.

The invention discloses a system and a method for power line carrier communication environmental testing. The system comprises an impedance noise measuring module, a master control module and a power supply module. The power supply module is connected with the impedance noise measuring module and the master control module to supply required work power supply to the impedance noise measuring module and the master control module. The master control module is used for sending control instruction to the impedance noise measuring module when testing instruction is impedance testing instruction or noise testing instruction so as to control the impedance noise measuring module to measure impedance sampling data or noise sampling data on a tested power line and obtain impedance sampling value or noise sampling value of the tested power line by calculating the sampling data, and therefore cause of power line carrier communication faults can be checked fast and conveniently.

The invention discloses a method for testing the optimal compaction density of lithium ion battery lithium iron phosphate positive plates. The method includes the following steps that positive plates are put into an oven to be baked for 12 h at 80 DEG C, then stamped, subjected to weighing, thickness measuring and rolling one by one and then put into the oven to be baked for 3 h at 80 DEG C; button batteries are made; forming is carried out, wherein two cycles of charging and discharging are carried out with 0.1 C current and 0.5 C current; charging is carried out, wherein charging is carried out to a semi-charged state with 0.1 C current; testing is carried out, wherein alternating-current impedance testing and linear scanning testing are carried out in sequence; data processing is carried out, wherein the gram volume is calculated, the exchange current density and the solid-phase diffusion coefficient of Li+ are calculated, and impedance fitting is carried out to obtain the internal resistance value; the result is analyzed, and when the gram volume, the exchange current density and the solid-phase diffusion coefficient of Li+ are the maximum and the internal resistance is the minimum, the battery performance is the optimal. By synthesizing the parameters, the compaction density of the positive plates corresponding to the batteries with the optimal performance is selected as the optimal compaction density of the positive plates.

The invention discloses a measuring device of switch power supply EMI noise source internal impedance that comprises line impedance stabilization network, common mode/differential mode impedance test module, signal generator and spectrum analyzer; power cord is directly input to the line impedance stabilization network, passes the common mode/differential mode impedance test module, and then input to the switch power supply and load to construct a whole power circuit; the signal generator provides a input signal for the common mode/differential mode impedance test module, response signal in the module is detected by the spectrum analyzer. The measuring method of switch power supply EMI noise source internal impedance IA also disclosed. The measuring device and method can measure the all-purpose internal impedance for all kinds of noise source, but also measure the unknown impedance, the accuracy is high and the operation is simple. The measuring method can judge the nature of internal impedance and provide a precondition for designing of EMI filter that is the designing of filter fulfills the impedance matching property of filter.

The invention discloses a detector for a lead-acid storage battery pole plate. The detector comprises a pressure testing machine, an impedance testing instrument, probes and a data collecting and processing device, wherein the pressure testing machine comprises upright posts and a supporting device arranged on an operating platform; each upright post is provided with a pressure sensor and probes,and each pressure sensor is used for collecting the interval of the corresponding probes and the pressure value; the impedance testing instrument is connected with the probes through wires, and is used for collecting direct current resistance value or alternating current resistance value; and the data collecting and processing device is connected with the pressure testing machine and the impedancetesting instrument, and is used for collecting and processing data of the pressure testing machine and the impedance testing instrument. Under the condition that the pole plate is not damaged, the resistance values or impedance values of spots at different parts on the pole plate and the thickness of the pole plate are measured, and the compatible dispersibility, uniformity and plate thickness uniformity of the components such as active substances and various additives inside the pole plate and the uniformity among different pole plates produced through same technology are judged through results capable of quantitatively judging data discretization in standard deviation, variance, average deviation and variable coefficient manners through the data collecting and processing device.