346 results about "Ohmic Resistance" patented technology

An electrochemical microfluidic device has one or a plurality of microstructures, such as a microchannel, in which an electrically conductive means is integrated to reduce the ohmic resistance within the microstructure and hence to improve electrochemical measurements particularly when large current densities are involved. The electrically conductive means can be connected as a counter-electrode and can be used to re-generate the product of the reaction occurring at the working electrode. A method of fabricating electrochemical microfluidic devices comprising such an electrically conductive means is also disclosed. The invention may particularly be used in all electrochemical sensor applications where detection is performed in small volumes.

A system and method for estimating internal parameters of a lithium-ion battery to provide a reliable battery state-of-charge estimate. The method uses a two RC-pair equivalent battery circuit model to estimate the battery parameters, including a battery open circuit voltage, an ohmic resistance, a double layer capacitance, a charge transfer resistance, a diffusion resistance and a diffusion capacitance. The method further uses the equivalent circuit model to provide a difference equation from which the battery parameters are adapted, and calculates the battery parameters from the difference equation.

A microapparatus (11) implantable in the eye (13) comprises a cuasi-bistable microvalve (21) commanded by an intraocular pressure sensor (23) in situ. The microvalve mechanism includes a diaphragm (27) made of a conjugated polymer (29) that shows high deformation and biocompatibility capabilities and which volume depends from the electric potential applied by its pair of electrodes (31). The sensor and actuator-valve are coupled to a drainage conduit (15), the first to deform by the pressure in the ocular globe and the second in a position of buckling to normally close the drainage conduit. The sensor us a membrane of conductive polymeric material with the same properties and whose ohmic resistance varies with the mechanical deformation produced by the ocular pressure.

A multiple phase buck converter or boost converter, or buck-boost converter has an inductor in each phase. The inductors are inversely coupled. In a first embodiment, the converter includes a toroidal magnetic core with inductors extending under and over opposite sides of the toroidal magnetic core. The coupled inductors are thereby inversely coupled and have a relatively low ohmic resistance. In a second embodiment, the converter comprises a ladder-shaped magnetic core (i.e. having parallel sides, and connecting rungs). In this case, the inductors extend under the sides, and over the rungs. Each inductor is disposed over a separate rung. The ladder-shaped magnetic core is preferably disposed flat on a circuit board. Inverse coupling and low ohmic resistance are also provided in the second embodiment having the ladder structure.

A multiple phase buck converter or boost converter, or buck-boost converter has an inductor in each phase. The inductors are inversely coupled. In a first embodiment, the converter includes a toroidal magnetic core with inductors extending under and over opposite sides of the toroidal magnetic core. The coupled inductors are thereby inversely coupled and have a relatively low ohmic resistance. In a second embodiment, the converter comprises a ladder-shaped magnetic core (i.e. having parallel sides, and connecting rungs). In this case, the inductors extend under the sides, and over the rungs. Each inductor is disposed over a separate rung. The ladder-shaped magnetic core is preferably disposed flat on a circuit board. Inverse coupling and low ohmic resistance are also provided in the second embodiment having the ladder structure.

The present invention concerns a fingerprint sensor which is small; demonstrates high sensitivity, low power consumption, high data acquisition rate and is insensitive to vibration and pressure. The sensor produces a high contrast fingerprint representation and is not subject to repeated deformation which could potentially reduces its lifetime. The fingerprint sensor has a microthermistor array for converting temperature variation into an electrical signal, the array being composed of a plurality of microthermistors, each of the thermistors being adapted to output an electrical signal proportional to a temperature variation; a read-out integrated circuit operatively connected to the microthermistor array for receiving the electrical signal and converting it into an electronic output signal representative of the ridge and valley structure of a finger; and a substrate for supporting the read-out integrated circuit and the microthermistor array. The invention is based on microthermistor array. The ohmic resistance of these sensors varies strongly with temperature. The parameter directly measured in this case is the temperature-induced resistance variation of each individual microthermistor. Signals from each of the microthermistor part of the array represent the fingerprint pattern.</PTEXT>

A method and apparatus for judging deterioration of a battery are provided, thereby a correct judgement for the deterioration of the battery can be timely carried out so as to replace the battery with another if it is necessary. The apparatus for judging deterioration of a battery that supplies electric power to a load includes: storing means 23c for storing a minimum guaranteed voltage predetermined as a minimum value of a terminal voltage of the battery 13 when a given current flows into the load; voltage drop computing means 23a for computing a voltage drop due to an ohmic resistance and polarization resistance of the battery occurred in response to a discharge of the battery when a given current flows from the battery into the load; first comparing means 23a for comparing the minimum guaranteed voltage stored in the storing means 23c with a first difference value, which is obtained by subtracting the voltage drop computed by the voltage drop computing means 23a from an open circuit voltage that corresponds to a state of charge upon a start of the discharge of the battery; and first deterioration judging means 23a for judging that the battery is deteriorated if the first difference value becomes equal to or smaller than the minimum guaranteed voltage and the state of charge upon the start of the discharge exceeds a first specific value as a result of the comparison by the first comparing means 23a.

The invention discloses a method for assessing an SOH (state of health) of a lithium ion battery. The method comprises the following steps: a, establishing an internal resistance model of the lithium ion battery; b, acquiring current and terminal voltage data of the lithium ion battery under different SOCs (states of charge), and storing the data if the change rate of two adjacent current values is not greater than a set value; c, performing fitting on the stored data by utilizing the internal resistance model of the lithium ion battery to obtain an R2-SOC curve and a tau-SOC curve of the lithium ion battery during a discharge process, and further, working out the ohmic resistance and the diffusion resistance of the lithium ion battery at the T moment; d, calculating the SOH value of the lithium ion battery; e, performing assessment on the SOH of the battery according to the SOH value of the lithium ion battery. According to the method for assessing the SOH of the lithium ion battery disclosed by the invention, different SOH assessment methods are adopted by the lithium ion battery under different SOCs, and therefore, the accuracy of an assessment result is greatly improved. By adopting the method, maintenance personnel can discover and eliminate hidden troubles of the battery in time to ensure the normal operation of an electric vehicle.

A battery model and equivalent circuit that includes an ohmic resistance, a first RC-pair that models a battery cell charge transfer reaction and double layer processes and a second RC-pair that models battery cell diffusion. Each of the ohmic resistance, the charge transfer reaction resistance and the diffusion resistance in the model are variable resistances, where each resistance changes in response to a change in voltage potential across the resistance.

In a method, computer program and system for determining an operational limit of a power transmission line, time-stamped current phasor information and voltage phasor information for a first end and a second end of the line are determined, an ohmic resistance of the line is computed from the phasor information, and an average line temperature is computed from the ohmic resistance. This allows to determine the average line temperature without dedicated temperature sensors. The average line temperature represents the actual average temperature and is largely independent of assumptions regarding line parameters.

The invention provides a total temperature-range lithium ion battery. The total temperature-range lithium ion battery comprises a multi-tab anode piece having a compound multi-layer coating structure, a multi-tab cathode piece having a compound multi-layer coating structure, a high temperature-resistant diaphragm and a high/low temperature composite electrolyte. Each one of two sides of a part 4 on positive and negative current collectors is orderly coated with a rapid charging/discharging layer 1 (1a, 1b), a transition layer 2 (2a, 2b) and a slow charging/discharging layer 3 (3a, 3b). Through the structure, the total temperature-range lithium ion battery has rapid charging/discharging performances without battery energy density reduction. Through the multi-tab structure, the high temperature-resistant diaphragm and the high/low temperature composite electrolyte, battery ohmic resistance and electrochemical interface impedance are reduced and battery safety is improved. The total temperature-range lithium ion battery can realize normal charging and discharging at a temperature of -40 to 75 DEG C and has excellent low-temperature high-magnification characteristics and high-temperature and long-life performances.

The invention discloses a metal support half-cell of a solid oxide fuel cell and a preparation method thereof. The half-cell comprises a porous metal supporting layer thick membrane, a porous cermet gradient transition layer film, a porous anode layer and a compact electrolyte layer film from down to up. The porous gradient transition layer composed of a mixed oxide and a oxide with a fluorite structuring can avoid the direct contact of the porous metal supporting layer and the porous anode layer, and the mutual diffusion of Fe/Cr elements in the metal supporting layer and Ni element in the porous anode layer can be reduced under high temperature sintering condition. The mixed oxide is reduced to an alloy under the work condition of the cell; a high anode active material is formed at a side interface of the anode, a high conductivity composite material which takes the alloy as a main phase is formed on the side interface of a metal support body, so that higher conductivity is presented, ohmic resistance is reduced, electrocatalytic activity is not reduced, long-term stability for operation of the cell can be ensured, and good combination of the porous metal supporting layer and the porous anode layer can be simultaneously realized.

A portable work apparatus has a combustion engine for driving a work tool. An air/fuel mixture is supplied to the engine via a carburetor which is provided with an electrical heating element for heating to a given temperature. The heating element is connected to a switch via which electrical energy, which is provided by a generator driven by the engine, is supplied. When a given temperature is exceeded, the switch interrupts the energy supply. To achieve an exact temperature control, the ohmic resistance value of the heating element is stored in a memory in dependence on the temperature. The current flowing through the heating element and the voltage drop at the heating element are measured and the instantaneous resistance of the heating element is calculated therefrom. This calculated value is compared to the value stored in the memory to open or close the switch in dependence on the comparison.

A method and device are disclosed for temperature manipulation of a melt even with conductivity below 10<-1> O <-1>cm<-1>, thus permitting refining of the melt at temperatures above 1700 DEG C. According to the method for temperature manipulation of a melt (16), in particular, in a refiner unit, the melt (16) is heated at least by ohmic resistance heating, at least two electrodes (4) are arranged in the melt (16) and at least a part of the melt (16) is cooled. The device (1) for temperature manipulation and/or refining and/or purification and/or homogenisation of a melt (16) comprises at least one arrangement for accommodating melt material (36, 16), defining an inner chamber and at least two electrodes (4) for ohmic resistance heating of the melt (16), wherein the electrodes (4) project into the inner chamber of the arrangement in particular of the vessel (2).

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.

A device for switching a semiconductor-based switch includes a terminal that is configured to be connected to a control terminal of the semiconductor-based switch. A controllable activation voltage source is configured to provide a time-varying activation voltage potential. A controllable resistive circuit includes at least two ohmic resistances connected in parallel that are controllable such that at least three resistance values of the parallel connection result. A control device is configured to control the controllable activation voltage source and the controllable resistive circuit independently of one another. The controllable activation voltage source and the controllable resistive circuit are connected to a series connection connected to the terminal. The control device is configured to control the controllable activation voltage source and the controllable resistive circuit in a time-varying manner to obtain time-varying resistance values of the controllable resistive circuit and the time-varying activation voltage potential of the controllable activation voltage source.

The invention discloses an aging early warning method of a power lithium battery. A power type MOSFET and a current limit resistor are connected with two ends of a battery pack, the MOSFET tube is conducted by 2ms under the control action of a controller, a single pulse current with width of 2ms is generated in the battery and the current limit resistor, and internal ohmic resistance of the lithium battery can be acquired according to voltage difference and a resistance value of the current limit resistor. Abnormal value elimination and data smooth processing for the power lithium battery ohminternal resistance data acquired in real time can be carried out, integral data is selected to carry out linear trend fitting of acquired gradient contrast to determine an aging inflection point, andearly warning of the battery health state is carried out. The method is advantaged in that internal ohmic resistance measurement of the power lithium battery can be simply and rapidly carried out, aging early warning of the power lithium battery is realized through utilizing the measured internal ohmic resistance data, and the method is of great importance to facilitating healthy development of the electric automobile industry.

In a capacitive voltage divider for measuring high voltage pulses with millisecond pulse duration comprising a high voltage divider including a first cascade of at least two serially arranged condensers of which one (C1) is disposed at the high potential end and another (C2) is disposed at the low potential end of the cascade, and a measuring voltage divider connected to the other condenser (C2) and including a second cascade of at least first and second serially arranged condensers (C3, C4) arranged, respectively, at the high and low potential ends of the second cascade with the second condenser being connected with its low voltage side to a signal supply line leading to a measuring device, and an ohmic resistor (R1) arranged in parallel with the first condenser and a resistance (R2) connected to the one and first condensers in parallel with the second condenser (C4), the ohmic resistor (R1) is so dimensioned that 1.1<C4*R2/C3*R1<1.15.