Abstract: Asymmetric power converter includes an upper bridge switch, a lower bridge switch, a primary winding, a first secondary winding, a second secondary winding, a control circuit. The first secondary winding and the second secondary winding output a first output voltage and a second output voltage of a secondary side of the asymmetric power converter respectively, and voltage polarity of the first secondary winding is different from voltage polarity of the second secondary winding. The control circuit controls the lower bridge switch and the upper bridge switch according to the first output voltage and the second output voltage, respectively.

Abstract: A wireless radio-frequency identification (RFID) strain sensor including: a substrate; an antenna on the substrate; and an integrated circuit on the substrate and electrically connected to the antenna. At least one of the substrate and the antenna includes a magnetoelastic material.

Abstract: Various embodiments include a method for monitoring the tank content of a storage tank comprising: metering a fluid from the tank into the exhaust gas tract, wherein the fluid has a concentration with respect to a reducing agent; acquiring a current concentration value for the reducing agent; calculating a change in concentration of the reducing agent on the basis of the current concentration value in comparison with a stored concentration value; determining a current operating state of the vehicle to identify an operating state in which refueling cannot be carried out; and carrying out a plausibility check of the calculated change in concentration if the calculated change in concentration exceeds a predetermined threshold value and the operating state is identified. The plausibility check includes acquiring the current tank filling level of the fluid.

Abstract: Systems and methods for controlling display of content using objects are disclosed. Objects may be placed on a surface and one or more computing devices may be configured to identify the objects, determine the shape of the objects, and/or determine the locations of the objects with respect to the surface. Content displayed on the surface may be updated based at least in part on interaction of the object with the surface, such as changing locations of the objects, object proximities, object flipping, and/or object stacking, for example.

Abstract: A sense unit for inductive sensing or capacitive sensing is described. The sense unit may include a first terminal coupled to a first node, a first electrode coupled to the first node, and a second terminal. The sense unit may include a second electrode coupled to the second terminal. In a first mode, a first signal is received at the first terminal and a second signal is output on the second terminal, where the second signal may be representative of a capacitance of the sense unit. The sense unit may include an inductive coil. The sense unit may include a first capacitor. The inductive coil and the first capacitor are coupled in parallel between the first node and ground. In a second mode, a third signal is received at the first terminal and a fourth signal is output on the second terminal.

Abstract: A system for detecting microwave power. In some embodiments, the system includes: a first resonator including a graphene-insulating-superconducting junction; a probe signal source, coupled to the first resonator; and a probe signal analyzer. The probe signal analyzer is configured: to measure a change in amplitude or phase of a probe signal received by the probe signal analyzer from the probe signal source, and to infer, from the change in amplitude or phase, a change in microwave power received by the graphene-insulating-superconducting junction.

Abstract: The present disclosure relates to a sensor for a capacitive determination of a filling level of a cartridge filled with a liquid substance. The sensor comprises a planar flexible foil arrangeable to an outer circumference of a tubular shaped barrel of the cartridge. The foil has at least a sensing zone, a communication zone and at least a first electrode. The foil further comprises least a second electrode located in the sensing zone, a processor electrically connected with the at least first and second electrodes, and an antenna located in the communication zone. The antenna is electrically connected with the processor.

Abstract: A package comprises a body, and an electrically conductive pattern supported by said body. An interface portion is configured to receive a module to a removable attachment with the package. The electrically conductive pattern comprises, at least partly within said interface portion, a wireless coupling pattern that constitutes one half of a wireless coupling arrangement.

Abstract: In some examples, a sensor comprises a circuit including an inductor. The inductor comprises an inductor layer, a reference layer comprising at least one of an electrically conductive material or a magnetic material, and a variable layer formed between the reference layer and inductor layer. A thickness of the variable layer may be configured to change upon application of a force external to the variable layer thereby causing a change in position of the reference layer relative the inductor layer, and the change in position of the reference layer relative the inductor layer changes an inductance of the inductor. The sensor may be configured to detect the force based on the change in inductance of the inductor.

Abstract: For initiating a control function based on a real time available fault current measurement, a measurement module measures an operating voltage, a short voltage, and a ring parameter of alternating current power lines. A processor calculates an impedance of the power lines as a function of the operating voltage, the short voltage, and the ring parameter. The processor further calculates a dynamic available fault current as a function of the impedance. In addition, the processor initiates a control function based on the available fault current.

Abstract: A resistance is measured without physical contact/connection to the resistance. A resistive element to be measured is provided, physically connected as part of a passive electrical circuit. Without physically contacting the resistive element, an electromagnetic field is used to produce an excitation in the passive electrical circuit. The resistance of the resistive element is determined based on an effect of the excitation on the electromagnetic field.

Abstract: A method for contactlessly checking the functionality of an antenna coil for a portable data carrier comprises the steps of exciting the antenna coil, detecting the free, damped oscillation of the antenna coil in response to the excitation, and evaluating the detected free, damped oscillation. The excitation of the antenna coil is effected inductively through a pulsed magnetic field, which may be generated by a single direct-current pulse, such as a Dirac pulse, by means of an exciting coil attached to a pulse generator. The detection of the oscillation of the antenna coil is effected through a measuring antenna, and the evaluation is effected by means of an evaluation device connected to the measuring antenna.

Abstract: Wireless sensors configured to record and transmit data as well as sense and, optionally, actuate to monitor physical properties of an environment and, optionally, effect changes within that environment. In one aspect, the wireless sensor can have a power harvesting unit; a voltage regulation unit, a transducing oscillator unit, and a transmitting coil. The voltage regulation unit is electrically coupled to the power harvesting unit and is configured to actuate at a minimum voltage level. The transducing oscillator unit is electrically coupled to the voltage regulation unit and is configured to convert a sensed physical property into an electrical signal. Also, the transmitting coil is configured to receive the electrical signal and to transmit the electrical signal to an external antenna.

Abstract: Methods and sensors for selective fluid sensing are provided. Each sensor includes a resonant inductor-capacitor-resistor (LCR) sensor that is coated with a sensing material. In order to collect data, an impedance spectrum is acquired over a relatively narrow frequency range, such as the resonant frequency range of the LCR circuit. A multivariate signature may be calculated from the acquired spectrum to discern the presence of certain fluids and/or fluid mixtures. The presence of fluids is detected by measuring the changes in dielectric, dimensional, resistance, charge transfer, and other changes in the properties of the materials employed by observing the changes in the resonant electronic properties of the circuit. By using a mathematical procedure, such as principal components analysis (PCA) and others, multiple fluids and mixtures can be detected in the presence of one another, even in a high humidity environment or an environment wherein one or more fluids has a substantially higher concentration (e.g.

Abstract: A wireless remote sensor (110) that is powered by an inductive transmitter (112) and is configured to produce an oscillating wave that varies based on one or more sensed parameters. The oscillating wave is communicated to the inductive transmitter (112) by reflected impedance, where it can be detected to determine the sensed value(s). In another aspect, the present invention provides a wireless remote sensor with a Wheatstone bridge arrangement having an internal resonant circuit to produce an electromagnetic field indicative of the sensed value. In a third aspect, the present invention provides a wireless remote sensor with optical feedback from a reference circuit and a sensor circuit. In a fourth aspect, the present invention provides a wireless remote temperature sensor having coils printed on a material with a high coefficient of thermal expansion so that the size and/or shape of the coils varies as the temperature increases or decreases.

Abstract: A method for measuring a capacitance using a capacitance meter. The capacitance meter includes an AC power source with a controllable frequency which is fed to a capacitor to measure its capacitance. A first measurement of the capacitance is performed by the capacitance meter using a first frequency. When the first measurement of the capacitance indicates the capacitance is below a threshold capacitance a lower capacitance measurement is performed in the capacitance meter, using a second measurement of the capacitance using a second frequency. When the first measurement of the capacitance indicates the capacitance is above a threshold capacitance, a higher capacitance measurement is performed in the capacitance meter, using a second measurement of the capacitance using a third frequency, the third frequency being lower than the second frequency.

Abstract: A detection coil is incorporated in a self-oscillation circuit. The oscillation frequency of the self-oscillation circuit, which comprises the coil and a capacitor, is set to a high frequency band (e.g., around 1 MHz or higher). A target section whose relative position to the coil section varies in response to displacement of a detection object, and includes a magnetism-responsive member constructed to cause inductance of the coil to vary with the relative position. A rectifier circuit extracts an amplitude level of an oscillation output signal of the self-oscillation circuit and outputs the extracted level as detected position data. For example, a plurality of self-oscillation circuits are provided. Alternatively, a single self-oscillation circuit forms a plurality of series circuits by, for each coil pair, connecting in series the two coils of the coil pair, and includes the result of connecting the series circuits in parallel as an inductor element for self-oscillation.

Abstract: A conductivity sensor is disclosed. The conductivity sensor includes an oscillator for providing an input signal and a reactive circuit having an induction coil, a capacitive element, and a resistive element connected in parallel. The induction coil is adapted to be placed adjacent to a specimen. The conductivity sensor further includes a control circuit for driving the reactive circuit to resonance when the induction coil is placed adjacent to the specimen. The reactive coil is configured to provide an output signal having a parameter representative of the conductivity of the specimen when the reactive circuit is at resonance. The induction coil may include a first conductive element that spirals outward to an external perimeter and a second conductive element operably connected to the first conductive element. The second conductive element spirals inward from the external perimeter staggered relative to the first conductive element.

Abstract: The present invention relates to a method and a system for on-site and full-scale testing of wind turbine plants. In particular, the present invention relates to a method and a system applying resonance circuits tuned with the fundamental frequency, or harmonics thereof, of a power supply grid connected to a wind turbine plant to be tested. The wind turbine plant to be tested may remain connected to the power supply grid during on-site and full-scale testing.

Abstract: A substrate including a sensor unit, wherein the sensor unit includes a coil wound at least once arranged on the surface of the sensor or embedded within and near the surface thereof. With such an arrangement, an electric current that corresponds to information with respect to the substrate (e.g., the temperature of the substrate or the amount of charge stored in the substrate) flows through the coil.

Abstract: It is an object to provide a test method of a process, an electric characteristic, and a mechanical characteristic of a structure body in a micromachine without contact. A structure body including a first conductive layer, a second conductive layer provided in parallel to the first conductive layer, and a sacrifice layer or a space provided between the first conductive layer and the second conductive layer is provided; an antenna connected to the structure body is provided; electric power is supplied to the structure body wirelessly through the antenna; and an electromagnetic wave generated from the antenna is detected as a characteristic of the structure body.

Abstract: Devices and methods of the invention can be used in many industries, including, but not limited to, utilities, agriculture, food, textile, pharmaceutical, photovoltaic and semiconductor, medical devices, chemical and petro-chemical, material science, and defense, where monitoring and/or analysis of various properties of materials are desired. Sensors and methods of using same are provided for measuring at least one impedance of an object under test (or a tested object) at a predetermined frequency and/or a predetermined frequency range, particularly where resonance conditions are provided for such measurement.

Abstract: Methods and sensors for selective fluid sensing are provided. A sensor includes a resonant inductor-capacitor-resistor (LCR) circuit and a sensing material disposed over a sensing region. The sensing region comprises at least a portion of the LCR circuit. Temperature-dependent response coefficients of inductance L, capacitance C, and resistance R properties of the LCR circuit and the sensing material are at least approximately 5 percent different from one another. The difference in the temperature-dependent response coefficients of the properties of the LCR circuit and the sensing material enables the sensor to selectively detect analyte fluids from an analyzed fluid mixture substantially independent of temperature.

Abstract: Methods and sensors for selective fluid sensing are provided. Each sensor includes a resonant inductor-capacitor-resistor (LCR) sensor that is coated with a sensing material. In order to collect data, an impedance spectrum is acquired over a relatively narrow frequency range, such as the resonant frequency range of the LCR circuit. A multivariate signature may be calculated from the acquired spectrum to discern the presence of certain fluids and/or fluid mixtures. The presence of fluids is detected by measuring the changes in dielectric, dimensional, resistance, charge transfer, and other changes in the properties of the materials employed by observing the changes in the resonant electronic properties of the circuit. By using a mathematical procedure, such as principal components analysis (PCA) and others, multiple fluids and mixtures can be detected in the presence of one another, even in a high humidity environment or an environment wherein one or more fluids has a substantially higher concentration (e.g.

Abstract: A method is disclosed for compensation of system tolerances in an inductive coupler which includes a power generator that feeds an alternating current into a series resonance circuit formed by a resonance capacitor and an inductive rotating transmission device. First, a brief sequence of at least one period of an alternating current is fed by the power generator into the series resonance circuit. Then the series resonance circuit is short-circuited. A first resonance frequency is measured. Then a longer sequence having a plurality of periods of an alternating-current voltage is generated by the power generator, so that a given small voltage is built up at the load. Now a second resonance frequency is measured while the resonance circuit is short-circuited. Then at least one correcting variable for the power generator is determined from the two resonance frequencies.

Abstract: A device for detecting and quantifying a force applied on a surface comprising a test specimen, an electrically insulating substrate, a first electrode bound to the substrate, a second electrode, an assembly of conductive or semi-conductive nanoparticles in contact with the two electrodes, and a measurement device. The measurement device provides proportional information with respect to an electrical property of the nanoparticles assembly. The electrical property is measured between the first and second electrode. The test specimen is the nanoparticles assembly itself and the electrical property is sensitive to the distance between the nanoparticles of the assembly. The invention uses the nanoparticles assembly itself as a test specimen and allows a force to be quantified even if the nanoparticles assembly is deposited on a rigid substrate.

Abstract: An automotive urea solution monitoring device is deployed in conjunction with the urea tank of a selective catalytic reduction vehicle. An RF signal of a constant frequency may be generated across a resonant circuit, which may be comprised of an inductor and a PCB trace capacitor, or the like. Electromagnetic radiation is propagated into the automotive urea solution in the urea tank. The conductivity and dielectric properties of the liquid change the impedance of the discrete/trace capacitor and or the discrete/trace inductor. These changes are proportional to ammonia content, temperature, and/or level of the automotive urea solution in the urea tank and are preferably detected by a microcontroller, or the like, and then transmitted to a selective catalytic reduction vehicle engine management system, or the like.

Abstract: A proximity sensor has an oscillation circuit, an amplitude measurement circuit, a control circuit and a signal processing circuit. The oscillation circuit has an LC resonant circuit and an oscillation control circuit that is configured to supply an electric current to the LC resonant circuit to generate oscillating voltage across the LC resonant circuit. The amplitude measurement circuit is configured to produce an amplitude signal corresponding to the amplitude of the oscillating voltage. The control circuit is configured to set the negative conductance of the oscillation control circuit to a critical value by which the LC resonant circuit can oscillate based on the amplitude signal. The signal processing circuit is configured to produce a distance signal corresponding to the distance between an object and the sensing coil based on a parameter associated with the negative conductance.

Abstract: A resonator arrangement has a conductive, semi-open outer housing, at an interior of which a conductive bar is provided disposed coaxially to the housing. At one end of the bar in a direction of a housing bottom, the bar has a die and, together with a dielectric and the housing bottom, forms a capacitor. The bar is short-circuited to the housing at another end, so that the bar and housing together form an LC oscillator circuit. Also disclosed is a method for analyzing a sample using a resonator arrangement.

Abstract: An assembly (1) for detecting an electric discontinuity that includes an exciter (6) connected, via at least one capacitor, to two contacts (2, 3) normally connected between them by an electrically conducting member (4). The circuit outside the exciter defines a resonating circuit having an impedance that changes upon the opening of one of the contacts. The frequency of the detection circuit, which varies between two values corresponding to the two open or closed states of the contacts, is used by an electronic processing module (8) that generates a dysfunctional signal upon opening of one of the contacts. The invention can be used in numerous fields, such as transport, handling, storage, etc.

Abstract: A conductivity sensor is disclosed. The conductivity sensor includes an oscillator for providing an input signal and a reactive circuit having an induction coil, a capacitive element, and a resistive element connected in parallel. The induction coil is adapted to be placed adjacent to a specimen. The conductivity sensor further includes a control circuit for driving the reactive circuit to resonance when the induction coil is placed adjacent to the specimen. The reactive coil is configured to provide an output signal having a parameter representative of the conductivity of the specimen when the reactive circuit is at resonance. The induction coil may include a first conductive element that spirals outward to an external perimeter and a second conductive element operably connected to the first conductive element. The second conductive element spirals inward from the external perimeter staggered relative to the first conductive element.

Abstract: Wireless sensors configured to record and transmit data as well as sense and, optionally, actuate to monitor physical properties of an environment and, optionally, effect changes within that environment. In one aspect, the wireless sensor can have a power harvesting unit; a voltage regulation unit, a transducing oscillator unit, and a transmitting coil. The voltage regulation unit is electrically coupled to the power harvesting unit and is configured to actuate at a minimum voltage level. The transducing oscillator unit is electrically coupled to the voltage regulation unit and is configured to convert a sensed physical property into an electrical signal. Also, the transmitting coil is configured to receive the electrical signal and to transmit the electrical signal to an external antenna.

Abstract: A method is provided for selectively detecting the presence and concentration of at least four analytes in a mixture. In certain embodiments, the method comprises contacting a single sensor with the mixture of analytes, wherein the sensor comprises at least one resonant sensor circuit comprising a sensing material that comprises at least two material properties that change in the presence of four or more analytes in their mixtures, and generating a multivariate sensor response pattern. The methods disclosed herein further optionally comprise performing analyte classification and analyte quantitation. Methods for selectively detecting the concentration of at least one analyte in a mixture further comprising at least one interference are also described in the instant application.

Abstract: Wireless sensors configured to record and transmit data as well as sense and, optionally, actuate to monitor physical properties of an environment and, optionally, effect changes within that environment. In one aspect, the wireless sensor can have a power harvesting unit; a voltage regulation unit, a transducing oscillator unit, and a transmitting coil. The voltage regulation unit is electrically coupled to the power harvesting unit and is configured to actuate at a minimum voltage level. The transducing oscillator unit is electrically coupled to the voltage regulation unit and is configured to convert a sensed physical property into an electrical signal. Also, the transmitting coil is configured to receive the electrical signal and to transmit the electrical signal to an external antenna.

Abstract: A test system for a radio frequency IC device includes a radio frequency IC chip and a radiation strip. The characteristics of the radio frequency IC device are measured by bringing the tip of a probe of a test apparatus in direct contact with a portion of the radiation strip and thereby providing a radio frequency signal. The tip of the probe is made to be a flat plate so as to obtain closer and more stable contact with the radiation strip.

Abstract: Methods and sensors for selective fluid sensing are provided. A sensor includes a resonant inductor-capacitor-resistor (LCR) circuit and a sensing material disposed over a sensing region. The sensing region comprises at least a portion of the LCR circuit. Temperature-dependent response coefficients of inductance L, capacitance C, and resistance R properties of the LCR circuit and the sensing material are at least approximately 5 percent different from one another. The difference in the temperature-dependent response coefficients of the properties of the LCR circuit and the sensing material enables the sensor to selectively detect analyte fluids from an analyzed fluid mixture substantially independent of temperature.

Abstract: A proximity and contact sensor (10) is provided with a sensor element (11) and a detection circuit (16). The sensor element is provided with a matrix (13) in which coil-shaped carbon fibers (12) are dispersed. A high-frequency oscillation circuit (19) of the detection circuit (16) supplies the sensor element with a high-frequency signal. A detector (22) in the detection circuit (16) receives an output signal from the sensor element (11) and detects proximity of an object (24). In one example, the coil-shaped carbon fibers (12) are contained in the matrix by 1 to 20% by weight. In another example, a high-frequency oscillation circuit generates a high-frequency signal of 100 to 800 kHz.

Abstract: An apparatus for measuring component performance including a feed line having an input port and an output port, a first resonator connected to the feed line, a first Josephson junction device connected to the first resonator and to ground, and a second resonator connected to the feed line and to ground.

Abstract: A non-contact power transmission device includes an alternating current power supply, a resonant system, a load, an impedance measuring section and an analyzing section. The resonant system has a primary coil connected to the alternating current power supply, a primary-side resonant coil, a secondary-side resonant coil and a secondary coil. The load is connected to the secondary coil. The impedance measuring section can measure the input impedance of the resonant system. The analyzing section analyzes the measurement results obtained from the impedance measuring section.

Abstract: An electronic ballast for driving a gas discharge lamp comprises an inverter circuit, a resonant tank circuit, and a control circuit operable to determine an approximation of a resonant frequency of the resonant tank circuit and to control the inverter circuit in response to the approximation of the resonant frequency. The control circuit determines the approximation of the resonant frequency by adjusting an operating frequency of a high-frequency inverter output voltage provided to the resonant tank circuit from a frequency above the resonant frequency down towards the resonant frequency, measuring the magnitude of a lamp voltage across the lamp, and storing the present value of the operating frequency as the resonant frequency when the magnitude of the lamp voltage reaches a maximum value. The control circuit may control the operating frequency of the inverter output voltage in response to the approximation of the resonant frequency and a target intensity of the lamp.

Abstract: Provided is a material for tactile sensor, which is easy to be formed, and in which the shape, size and orientation of coils dispersed in the medium are sufficiently controlled. The tactile-sensitive material includes a medium and a plurality of micro coils dispersed in the medium and constituting a LCR resonance circuit, and wherein each of the plurality of micro coils includes at least one spiral coil portion, and coil axes of the plurality of micro coils are aligned along at least one direction or directed in at least one plane. When a tactile stress is applied to the tactile-sensitive material, the C component is varied significantly, which contributes to the improvement in sensitivity of the tactile sensor. Further, by providing a core at the coil center, the sensitivity is more improved.

Abstract: The present invention relates to a method and a system for on-site and full-scale testing of wind turbine plants. In particular, the present invention relates to a method and a system applying resonance circuits tuned with the fundamental frequency, or harmonics thereof, of a power supply grid connected to a wind turbine plant to be tested. The wind turbine plant to be tested may remain connected to the power supply grid during on-site and full-scale testing.

Abstract: An apparatus for determining a resonant frequency of a wind turbine tower is provided. The apparatus includes a processing unit configured to receive an acceleration measurement value, the acceleration measurement value representative of the acceleration of the wind turbine tower in the direction parallel to a rotor rotational axis of the wind turbine and/or in the direction perpendicular to both the rotor rotational axis and the tower axis of the wind turbine. The apparatus includes a memory configured to store a series of acceleration measurement values, and the processing unit includes a Fourier transform module configured to calculate a spectral vector based on calculating a convolution-based fast Fourier transform of the series of acceleration measurement values, and includes a resonant frequency calculation module configured to calculate the tower resonant frequency based on the calculated spectral vector.

Abstract: A method is disclosed for compensation of system tolerances in an inductive coupler which includes a power generator that feeds an alternating current into a series resonance circuit formed by a resonance capacitor and an inductive rotating transmission device. First, a brief sequence of at least one period of an alternating current is fed by the power generator into the series resonance circuit. Then the series resonance circuit is short-circuited. A first resonance frequency is measured. Then a longer sequence having a plurality of periods of an alternating-current voltage is generated by the power generator, so that a given small voltage is built up at the load. Now a second resonance frequency is measured whilst the resonance circuit is short-circuited. Then at least one correcting variable for the power generator is determined from the two resonance frequencies.

Abstract: An oscillator circuit includes a phase-locked loop, a crystal resonator, first and second capacitors, and first and second impedance elements. The phase-locked loop is coupled between a first node and a second node. The crystal resonator is also coupled between the first node and the second node. The first capacitor is coupled between the first node and ground, and the second capacitor is coupled between the second node and ground. The first impedance element is coupled in a first circuit path from the first node to ground through the first capacitor. The second impedance element is coupled in a second circuit path from the second node to ground through the second capacitor.

Abstract: A plurality of through-hole vias connected to conductor layers is disposed with gaps left between these vias around opening parts disposed in the conductor layers in a printed board in which these conductor layers are disposed parallel to each other so as to sandwich a dielectric layer in between. Furthermore, through-hole vias used for excitation are disposed in the opening parts of the conductor layers and regions of the dielectric layer matching these opening parts in a non-contact manner with the conductor layers. When the complex dielectric constant is measured, a high-frequency power is applied to the through-hole vias, and the power loss between the through-hole vias and the conductor layers is measured by the S parameter method.

Abstract: A method for determining whether a quantum system comprising a superconducting qubit is occupying a first basis state or a second basis state once a measurement is performed is provided. The method, comprising: applying a signal having a frequency through a transmission line coupled to the superconducting qubit characterized by two distinct, separate, and stable states of differing resonance frequencies each corresponding to the occupation of the first or second basis state prior to measurement; and measuring at least one of an output power or phase at an output port of the transmission line, wherein the measured output power or phase is indicative of whether the superconducting qubit is occupying the first basis state or the second basis state.

Abstract: Disclosed is a very low frequency test generator for generating a high voltage having a low frequency in order to test the insulation of capacitive loads, in particular power cables. Said VLF test generator comprises two oscillators, the frequencies of which differ from one another by twice said low frequency, a resonance circuit which is fed in an interfering manner by the oscillators, is adjusted to the oscillator frequencies and causes a voltage rise of the interfering oscillator frequencies, and a demodulator for disconnecting the low-frequency high voltage generated by the interference from the resonance circuit and applying the same to the load.

Abstract: The invention relates to an electrical measuring device for performing an electrical impedance measurement in a contactless manner. The measuring device comprises a measuring unit which is provided with the impedance to be measured and a passive resonance circuit connected thereto for generating a measuring signal to be wirelessly received by a separate active transmitting and receiving unit for determination of the electrical impedance, upon wireless reception of an interrogation signal transmitted by the active transmitting and receiving unit. Further, the measuring unit is provided with an additional reference circuit which is preferably connected to the resonance circuit for, depending upon the interrogation signal, generating a reference signal to be received by the active transmitting and receiving unit.

Abstract: Provided is a material for tactile sensor, which is easy to be formed, and in which the shape, size and orientation of coils dispersed in the medium are sufficiently controlled. The tactile-sensitive material comprises a medium and a plurality of micro coils dispersed in the medium and constituting a LCR resonance circuit, and wherein each of the plurality of micro coils comprises at least one spiral coil portion, and coil axes of the plurality of micro coils are aligned along at least one direction and/or directed in at least one plane. When a tactile stress is applied to the tactile-sensitive material, the C component is varied significantly, which contributes to the improvement in sensitivity of the tactile sensor. Further, by providing a core at the coil center, the sensitivity is more improved.