Abstract: A displacement detecting apparatus includes a first electrode including a base electrode segment and a plurality of detecting electrode segments, a second electrode having a predetermined periodic pattern and movable relative to the first electrode, a detector configured to detect a displacement based on a capacitance between the first electrode and the second electrode, and a wiring configured to connect the plurality of detecting electrode segments and the detector with each other. A portion of the wiring facing the second electrode is located opposite to the second electrode with respect to the base electrode segment.

Abstract: Systems, methods and piezoelectric patches are provided for monitoring the structural health of connectors in overhead transmission lines. A plurality of piezoelectric patches is mounted to different locations on the connector. At least one of the patches is actuated using an AC voltage and certain electrical properties either from the same patch or of a different patch are evaluated over time to determine the structural health of the connectors.

Abstract: An electric field type time-grating linear displacement sensor based on a single row multilayer structure, including a moving ruler and a fixed ruler. The moving ruler having a row of induced electrodes and the fixed ruler having a row of excitation electrodes.

Abstract: An electric field type time-grating angular displacement sensor, including a rotor and a stator. The rotor includes m rotor electrodes. The rotor electrodes cover a circle on a surface of a rotor body with equal space. The stator includes 4m stator electrodes. The stator electrodes cover a circle on a surface of a stator body with equal space.

Abstract: A sensor array includes a first sensor element of a unit cell and a second sensor element of the unit cell. The unit cell includes core traces of the first sensor element, where the core traces are the widest portion of the first sensor element. The unit cell includes main traces of the second sensor element and subtraces of the second sensor element, where each main trace crosses the first sensor element at a corresponding bridge to form an intersection of the unit cell.

Abstract: Disclosed are several examples of a system and method for detecting if an article is being tampered with. Included is a covering made of a substrate that is coated with a layer of an electrically conductive material that forms an electrically conductive surface having an electrical resistance. The covering is configured to at least partially encapsulate the article such that the article cannot be tampered with, without modifying the electrical resistance of the electrically conductive surface of the covering. A sensing device is affixed to the electrically conductive surface of the covering and the sensing device monitors the condition of the covering by producing a signal that is indicative of the electrical resistance of the electrically conductive surface of the covering. A measured electrical resistance that differs from a nominal electrical resistance is indicative of a covering that is being tampered with and an alert is communicated to an observer.

Abstract: A metal-to-metal leakage and breakdown testing structure for semiconductor structures and method of using the testing structure is disclosed. The testing structure includes plurality of resistor bridges connected to respective two terminal devices. The testing structure further includes a plurality of switches each having a voltage node provided between resistors of a respective one of the plurality of resistor bridges. The voltage node is read at a circuit pad when a respective one of the plurality of switches is in an on state. The testing structure further includes a device turning on and off each of the plurality of switches, individually.

Abstract: A pressure detector detecting a pressure of cold or hot water; a temperature detector detecting a temperature of a pressure sensor; correcting equation storage storing, cold water correcting equation information applied when the temperature detected by the temperature detector is included in a cold water temperature range, and hot water correcting equation information applied when the temperature detected by the temperature detector is included in a hot water temperature range; a temperature range determiner determining the temperature range that includes the temperature detected by the temperature detector as either a cold water temperature range or a hot water temperature range; and a correction calculating portion using the correcting equation corresponding to the temperature range determined by the temperature range determiner correcting the detection signal by the pressure detector, and outputting the post-correction signal as a measurement signal.

Abstract: Provided is a system and associated method for detecting a resistance of a cable. An example method may comprise applying power to a first end of a first and a second conductive pair of the cable, measuring a first voltage across the first end of the first and second conductive pairs of the cable, applying a current source across the first end of a third and a fourth conductive pair of the cable, measuring a second voltage across the current source, and determining a resistance of the cable using the measured first and second voltages. This method may be carried out in a physical arrangement where a second end of the first, second, third and fourth conductive pairs of the cable are connected to a first, a second, a third and a fourth input terminal of a powered device, respectively.

Abstract: A circuit for simulating an electrical load at a terminal of a test circuit having at least one first switch and at least one second switch includes a third switch connected to the first switch of the test circuit via a first external connection point. A fourth switch is connected to the second switch of the test circuit via a second external connection point. The first switch and the second switch are connected via a shared, first internal connection point to the terminal of the test circuit and the third switch and the fourth switch are connected via a shared, second internal connection point such that that the first switch, the second switch, the third switch and the fourth switch form an H-bridge circuit. A voltage source is configured to provide the first and second external connection points with a supply voltage. A controllable voltage source is connected in a transverse bridge branch between the terminal and the second internal connection point. An inductance is active in the transverse bridge branch.

Abstract: A device for detecting the thinning down of the substrate of an integrated circuit chip, including, in the active area of the substrate, bar-shaped diffused resistors connected as a Wheatstone bridge, wherein: first opposite resistors of the bridge are oriented along a first direction; the second opposite resistors of the bridge are oriented along a second direction; and the first and second directions are such that a thinning down of the substrate causes a variation of the imbalance value of the bridge.

Abstract: A field device, comprising a sensor, and a control/evaluation unit. The control/evaluation unit is implemented on an application-specific integrated circuit—an ASIC—which, in at least a first section and in a second section, is embodied as a dynamically reconfigurable logic chip. In each of the two sections, in each case, a measuring path composed of a plurality of function modules can be configured; wherein the individual sections are spaced apart from one another in such a manner, that a temperature and/or a voltage change in one of the sections has no influence on the other section or the other sections. The control/evaluation unit partially dynamically reconfigures the function modules in the measuring paths as a function of the particular defined safety-critical application, so that the field device fulfills the required safety standard.

Abstract: The invention inter alia relates to a method for monitoring the bearing current of an electrical machine (10). An electrode (100) arranged at a distance (d) to a shaft and the shaft—due to the gap (S) between the electrode and the shaft—produce a measurement capacitance (C) and an electric shift current (i) which flows through the measurement capacitance when there is a temporal change of the voltage (Ug) applied between the shaft and the housing is measured. A measurement signal (Ms) indicating a bearing current flow is generated when the shift current or a measurement variable produced by the shift current meets a predetermined trigger criterion. Preferably, the electrode has a circular inner contour so that the gap is annular. The annular inner contour results in an error compensation in the case of a balance error of the shaft because the factor dC/dt remains at least substantially constant. Due to the contactless measurement of the shift current, no contact brushes for contacting the shaft are required.

Abstract: A detector is provided that detects a detection signal corresponding to a driving vibration, which excites a vibrator in an oscillation loop, and a physical quantity to be measured. The detector includes an amplifying circuit, a synchronous detection circuit, an impedance conversion circuit, a first low pass filter, and a second low pass filter, wherein each of the first and second low pass filters is formed by a switched capacitor filter circuit, a gain of the first low pass filter is different from that of the second low pass filter.

Abstract: An apparatus for optimizing a Wheatstone bridge robust in a temperature change, the apparatus including; a voltage difference measuring unit which measures a voltage difference between a current input end and a current output end of the Wheatstone bridge, wherein the Wheatstone bridge comprises a first resistor, a second resistor, a third resistor and a fourth resistor and a tuning resistor; and a resistance tuning controller which detects a resistance ratio of a first distribution resistance and a second distribution resistance of the tuning resistor so that the voltage difference measuring unit measures a maximum voltage difference, and controls tuning of the tuning resistor according to the detected resistance ratio.

Abstract: A self-balancing Wheatstone bridge that provides frequency and power information. The frequency information obtained can be applied to correct the power measurement to provide excellent match, excellent frequency insensitivity, good dynamic range, good frequency range, and adequate frequency accuracy. The system is highly responsive, simple, and cost effective.

Abstract: The impedance of ionic solutions may be determined using a bridge circuit where the ionic solution forms one leg of the bridge circuit and a reference impedance characterized by a reference time constant forms a second leg of the bridge circuit. The bridge is driven by a switched DC voltage waveform. Measurement of the ionic solution is delayed after switching to allow the reference impedance to reach its asymptotic value. The reference impedance may be varied to reduce the reference time constant.

Abstract: A resistance testing apparatus makes use of a modular design for cascaded, parallel, bipolar current sources to obviate the need for electromechanical or pneumatic switching systems.

Abstract: A method for measuring an on resistance in an H-bridge including first and second transistors connected to a first output terminal, third and fourth transistors connected to a second output terminal, and a measurement switch connected to the first and second output terminals. The first and third transistors are connected to a first power supply terminal. The second and fourth transistors are connected to a second power supply terminal. The method includes supplying the first transistor with measurement current during a first period, measuring a first voltage at the first power supply terminal via the third transistor using the second output terminal during the first period, measuring a second voltage at the first output terminal via the measurement switch using the second output terminal during the first period, and determining the on resistance of the first transistor based on the measurement current, first voltage, and second voltage.

Abstract: A measuring bridge arrangement has a measuring bridge with a first supply terminal and first and second measuring signal terminals. The measuring bridge arrangement has a working point adjustment circuit formed to feed the measuring bridge via at least the first supply terminal in a measuring state of operation, and to apply a signal to one of the measuring signal terminals in the test state of operation in order to bring the measuring bridge to a test working point different from a measuring working point in the measuring state of operation. The measuring bridge has a test tap, wherein a test signal dependent on resistive properties of at least one element of the measuring bridge can be tapped at the test tap of the measuring bridge.

Abstract: A self-balancing Wheatstone bridge that provides frequency and power information. The frequency information obtained can be applied to correct the power measurement to provide excellent match, excellent frequency insensitivity, good dynamic range, good frequency range, and adequate frequency accuracy. The system is highly responsive, simple, and cost effective.

Abstract: A pressure sensing apparatus including: at least one deflectable diaphragm having a center, wherein each diaphragm supports: at least one positive piezoresistive gauge and at least one negative piezoresistive gauge coupled in series across a voltage differential in a half-Wheatstone bridge configuration having an output between the positive and negative piezoresistive gauges; and, a compensating piezoresistive gauge coupled in series with the half-Wheatstone bridge configuration across the voltage differential; wherein, the compensating piezoresistive gauge is nearer the center of the diaphragm than the negative piezoresitive gauge, the negative piezoresitive gauge is nearer the center of the diaphragm than the positive piezoresitive gauge, and the compensating piezoresistive gauge linearizes the half-Wheatstone bridge output.

Abstract: The impedance of ionic solutions may be determined using a bridge circuit where the ionic solution comprises a leg of the bridge circuit and a reference impedance characterized by a reference time constant comprises a second leg of the bridge circuit. The bridge is driven by a switched DC voltage waveform. Measurement of the ionic solution is delayed after switching to allow the reference impedance to reach its asymptotic value. The reference impedance may be varied to reduce the reference time constant.

Abstract: Nanoscale impedance microscopy and related methods, circuit and/or apparatus capable of quantitatively measuring magnitude and phase of alternating current flow.

Abstract: A method and a device for detecting the degree of pollution in an operational converter are disclosed. An operating state of at least one of the converter components that is exposed to the ambient air is determined and a corresponding operating state of said component in an unpolluted state is determined. The two operating states are then compared and the calculated comparison value is used as a measurement for the degree of pollution of the converter. Detecting the degree of pollution of an operational converter permits a reduction in the number of breakdowns caused by unprotected operation of a converter, and associated disadvantages such as costs and damage to a company's image.

Abstract: A measuring bridge arrangement has a measuring bridge with a first supply terminal and first and second measuring signal terminals. The measuring bridge arrangement has a working point adjustment circuit formed to feed the measuring bridge via at least the first supply terminal in a measuring state of operation, and to apply a signal to one of the measuring signal terminals in the test state of operation in order to bring the measuring bridge to a test working point different from a measuring working point in the measuring state of operation. The measuring bridge has a test tap, wherein a test signal dependent on resistive properties of at least one element of the measuring bridge can be tapped at the test tap of the measuring bridge.

Abstract: A return loss bridge circuit for testing a balanced test impedance includes an input connector and a reflection connector. The input connector and the reflection connector are electrically connected to an output of a network analyzer and an input of the network analyzer, respectively. The return loss bridge circuit further includes a reference impedance connected between the input and reflection connectors, first and second transformers and a common mode choke. The common mode choke is electrically connectable to the balanced test impedance.

Abstract: A structural health monitoring circuit apparatus and method are based on electrical impedance variations of a piezoelectric patch, which is attached to a structure to be monitored. The circuit compares a known good sweep of frequency-impedance pairs with a contemporaneous sweep to generate an alarm when an error bound is exceeded. The impedance of the piezoelectric patch is determined though adjustment of a variable reactance in a bridge configuration. By suitable design of the bridge elements, the electrical impedance of the piezoelectric patch may be directly measured. A microprocessor controlled version of this device consumes less than 2 W of power, which may be further reduced by further large scale integration or reduction to a state machine on a programmable gate array. Ultimately, this device may give personnel warnings to aircraft, automobiles, bridges, elevated roads, buildings, or home structural failures.

Abstract: A method for finding the impedance of a device under test using an impedance measuring apparatus having a modem-type auto-balancing bridge, two or more measurement signals, each of which has a different phase with respect to the reference signals supplied to the modem inside said auto-balancing bridge, are applied to a device under test; the impedance of this device under test is measured when each of the measurement signals is applied to the device under test; and the impedance of this device under test is found using the above-mentioned phase and the impedance measurement value of each of these measurements.

Abstract: A method for the temperature compensation of a resistance measuring bridge, such as in particular a Wheatstone bridge, is characterized in that a capacitor positioned between the input circuit and a resistance switching circuit of the Wheatstone bridge is successively discharge by means of at least one Wheatstone bridge resistor. In a device for the temperature compensation of a measuring bridge, particularly a Wheatstone bridge, having a measuring bridge and a compensating resistor in the input circuit, one or two switches are located in the resistance switching circuit branch of the measuring bridge as a contact point with the latter and a capacitor is located between the input circuit and the resistance switching circuit branch.

Abstract: A method and an apparatus for testing a bridge circuit. The method includes inputting a first test clock to a first conversion unit for triggering the first conversion unit to transfer a test data to a second conversion unit according to rising edges of the first test clock, inputting a second test clock to the second conversion unit for triggering the second conversion unit to output an output data according to falling edges of the second test clock, and controlling the first test clock and the second test clock so that the rising edges of the second test clock are not synchronized to the rising edges of the first test clock. A frequency of the first test clock is an even multiple of a frequency of the second test clock.

Abstract: A circuit for measuring the mass air flow rate through a duct is disclosed. The circuit includes a bridge circuit, a first amplifier, an oscillator, a comparator and a switch. The bridge circuit has a plurality of resistors arranged to output first and second bridge voltage signals. The first amplifier circuit receives the first and second bridge voltage signals and generates a differential bridge voltage signal. The oscillator provides an oscillating control signal. The comparator is in communication with the first amplifier circuit and the oscillator for comparing the differential bridge voltage signal to the oscillating signal to generate a pulse width modulated differential bridge voltage signal. The switch is in communication with the bridge circuit and the comparator. The switch selectively provides a power voltage signal to the bridge circuit at a frequency corresponding to the pulse width modulated differential bridge voltage signal.

Abstract: Methods and systems using Pade' Approximant expansion ratios provide mappings between nonlinear sensors and a more linearized output domain. In one embodiment (a) a variable gain amplifier receives a supplied input signal, the amplifier has at least a first input terminal, an output terminal, and a gain control terminal; (b) a first summer coupled to the output terminal of the variable gain amplifier adds in a first offset signal; (c) a first multiplier coupled to an output of the first summer receives a proportional feedback factor signal and correspondingly generates a multiplied feedback; (d) a second summer coupled to an output terminal of the first multiplier adds in a corresponding second offset signal; and (e) a second multiplier coupled to an output of the second summer receives a gain factor signal and generates a multiplied gain signal; where the gain control terminal of the variable gain amplifier is operatively coupled to an output terminal of the second multiplier.

Abstract: A physical quantity sensing device includes a bridge circuit that has first and second input points, to which an AC voltage is applied, and first and second output points connected to a differential amplifier. The bridge circuit includes a first bridge arm for electrically connecting the first input point to the first output point, a second bridge arm for electrically connecting the first output point to the second input point, a third bridge arm for electrically connecting the first input point to the second output point and a fourth bridge arm for electrically connecting the second output point to the second input point. The first bridge arm includes a first sensor element, of which the impedance changes with a physical quantity to be measured, and the second bridge arm includes a second sensor element, of which the impedance also changes with the physical quantity to be measured. The total impedance of the first and second bridge arms is smaller than that of the third and fourth bridge arms.

Abstract: An instrumentation current loop, including a transducer having transducer output terminals. A power source is connected in series to the transducer. A bridge has a first arm and a second arm extending between a pair of input terminals, where the input terminals of the bridge are connected to the transducer output terminals. The first arm comprises a first resistance and a second resistance connected via a first junction. The second arm comprises a third resistance and a fourth resistance providing a voltage reference connected via a second junction. A meter is connected between the first junction and the second junction. Values of the first, second, third and fourth resistance are selected so that a given range of input current provided by the transducer output terminals and supplied to the input terminals of the bridge is converted to a desired range of output current for the meter.

Abstract: A physical quantity sensing device includes an AC voltage generator for generating an AC voltage and a bridge circuit that has first and second input points, to which the AC voltage is applied, and first and second output points connected to a differential amplifier. The bridge circuit includes first and second sensor elements, the impedance of which change with a physical quantity to be measured. The first and second sensor elements have a positive temperature characteristic in which sensitivity increases as temperature rises. The AC voltage generator includes an amplitude limiter which has a negative temperature characteristic that decreases the amplitude of the AC voltage with a rise in temperature, thereby compensating for temperature dependence of a differential voltage produced between the first and second output points.

Abstract: In the method and circuit arrangement for offset correction of the measurement bridge, the full bridge signal and half bridge signal of the measuring bridge are measured; a self-adjustment of the half bridge signal path to an output signal of the full bridge signal bath is performed to adjust the half bridge signal to the full bridge signal for each measurement cycle between turn on and turn off of the measurement bridge; and an offset value of the half bridge signal path is determined at a time of turning on and the offset value is kept constant during a given measurement cycle.

Abstract: A circuit for sensing radio frequency energy. The circuit includes a Wheatstone bridge having at least one element thereof thermally responsive to the radio frequency energy passing therethough differently from radio frequency energy passing though at least one other element of the bridge.

Abstract: A semiconductor sensing device has a semiconductor substrate with a pressure sensing bridge circuit including piezo-resistance elements formed on the substrate. Further, the semiconductor sensing device has a temperature sensing bridge circuit including resistance elements formed on the semiconductor substrate. A pair of the resistance elements is connected with a power supply terminal, and the other pair of the resistance elements is connected with a grounding terminal. The resistance elements in either or both of these pairs are formed of different resistance types from each other and of the same conductivity type.

Abstract: An Audio Feedback Impedance Comparison Device to audibly express Impedance differences between/amongst components, circuits, materials, substances etc., to make use of the aural sense, while relieving eye, neck and mental strain, as well as reduce probe time. This is achieved by allowing simultaneous yet focused attention to be paid to all aspects of an impedance probe, i.e. hand-eye coordination of probe positioning, while aurally monitoring the feedback, instead of the common practices/methods where eyes have to be re-focused on visual feedback devices. The use of an alternating signal allows “through” comparison, where multiple components some of which are impervious to static signal, contribute to overall impedance. The device can be used to inject and/or detect/trace the presence of an audio signal in an active circuit. With the aid of transducers, this Device may be used with other forms of energy.

Abstract: A current comparator technique is applied to four-terminal resistance measurements for obtaining a highly accurate AC resistance bridge at power frequencies of 50 Hz to 60 Hz. Active circuits are used to establish equal voltage drops between the potential terminals of the two resistances being compared. The bridge is suitable for measuring resistances from 10 &mgr;&OHgr; to 100 k&mgr;&OHgr;. A cascading technique using two two-stage current transformers provides extension of the ratio range to 100,00,000 with a maximum applied current of 10,000 A. The bridge features measurement with a resolution of 0.1×10−6. The total combined uncertainty (2&sgr;) of the bridge including the range extenders, at power frequencies, is estimated to be less than 5 &mgr;&OHgr;/&OHgr;.

Abstract: Disclosed is a novel electrical probe that stores probe-specific information. A probe implemented in accordance with the invention includes a processor, memory, and a communications interface. Probe-specific information such as a probe identifier and/or calibration parameters that affect the true value of a measurement are stored in the probe memory. The probe-specific information may be retrieved by the processor from the probe memory via the communications interface.

Abstract: A semiconductor sensing device has a semiconductor substrate with a pressure sensing bridge circuit including piezo-resistance elements formed on the substrate. Further, the semiconductor sensing device has a temperature sensing bridge circuit including resistance elements formed on the semiconductor substrate. A pair of the resistance elements is connected with a power supply terminal, and the other pair of the resistance elements is connected with a grounding terminal. The resistance elements in either or both of these pairs are formed of different resistance types from each other and of the same conductivity type.

Abstract: An ASIC (14, 14′, 14″) conditions two independent outputs (VINM, VINP) of a full Wheatstone piezoresistive bridge (12) in separate conditioning paths. Each path is provided with a bridge supply voltage (VHB1, VHB2) which can serve as a temperature related input signal to respective offset and gain compensation control circuits. The half bridge outputs are inputted to respective amplifiers (U1, U2) along with a selected percentage of the temperature dependent bridge supply voltage. The outputs of the amplifiers provide a signal proportional to respective half bridge output voltage. In one embodiment, the output of the amplifier (U2) in one conditioning path of one half bridge is connected to the input of an amplifier (U4) in the other conditioning path to provide a signal in the one path proportional to the Wheatstone bridge differential output voltage and in the other path a signal proportional to the Wheatstone half bridge output voltage.

Abstract: The voltage corresponding to the pressure outputted from a Wheatstone bridge having resistors R1 to R4 is amplified by a differential amplifier 3 and operational amplifiers OP1, OP2, and then outputted through an output terminal 4 to an external device as the output voltage VOUT. The offset voltage ZSOUT is outputted from the operational amplifier OP10. The output voltage VOUT and the offset voltage ZSOUT are fed back to the reference source voltage Vsen by operational amplifiers OP3 to OP5. In consequence, a non-linear output property of output-attenuating or output-increasing type can be easily obtained, while errors due to the offset voltage ZSOUT can be diminished.

Abstract: A thermal conduction vacuum gauge using a Peltier tip is provided. The vacuum gauge for measuring the pressure in a vacuum chamber includes: a signal generator that drives an electric current; an ammeter connected to the signal generator for measuring the current; a bridge circuit consisting of junctions of thermocouple wires, which is connected to the ammeter, wherein one junction of the dissimilar metallic wires is made in the form of a Peltier tip inserted into the vacuum chamber; and a lock-in amplifier connected to the two symmetrical points of the bridge circuit for detecting a voltage signal due to the temperature oscillation at the Peltier tip and thus measuring the pressure in the vacuum chamber.

Abstract: First and second resistors (sensing elements) are connected in series between first and second potentials. The junction point voltage between the first and second resistor is supplied to an inverting input of a first operational amplifier. The non-inverting input is supplied with a reference voltage Vref generated by third and fourth resistors. A feedback resistor is connected between output and inverting input of the operational amplifier OP1. The difference between a temperature coefficient of resistance TCR of the sensing elements and a temperature coefficient of sensitivity TCS is equalized to a temperature coefficient of resistance of the feedback resistor. Further, the reference voltage is unchanged in accordance with the detected physical quantity or temperature variation.

Abstract: A self-balanced active current bridge for measuring the impedance of an external device or an output current, comprising an input potential source and operation amplifier connected to the input potential source via a first input terminal of the operation amplifier. A balancing bridge is coupled to a first output terminal and a second output terminal of the operation amplifier. A controlled potential source is coupled to the balancing bridge and used to maintain the balance state of the balancing bridge. A resistance is connected between the balancing bridge and an output terminal of the controlled potential source. Wherein the external device is connected a first node between the balancing bridge and a second input terminal of the operation amplifier.

Abstract: A self-balanced active current bridge for measuring the impedance of an external device or an output current, including an input potential source and operation amplifier connected to the input potential source via a first input terminal of the operation amplifier. A balancing bridge is coupled to a first output terminal and a second output terminal of the operation amplifier. A controlled potential source is coupled to the balancing bridge and used to maintain the balance state of the balancing bridge. A resistance is connected between the balancing bridge and an output terminal of the controlled potential source. Wherein the external device is connected a first node between the balancing bridge and a second input terminal of the operation amplifier.

Abstract: A demodulator is provided for demodulating an amplitude-modulated input signal defined by a carrier signal having a carrier frequency modulated by a modulating signal, the demodulator including an amplifier stage having a gain and structured to receive the amplitude-modulated input signal, and a gain control stage coupled to the amplifier stage and configured to vary the gain of the amplifier stage according to the carrier frequency of the carrier signal.