Search

Background. The aim of the study is to determine a frequency integrating unfolding converter parameters based on a bridge circuit with semiconductor strain gages to compensate for the of the output signal error resulting from the strain gages parameter's technological spread and the effects of elevated temperature. Materials and methods. The work employs methods of semiconductor strain gauge analysis, electrical circuit calculations, mathematical modeling using specially developed programs to determine the temperature and process-induced error dependence of the output signal of a frequency integrating unfolding converter based on a bridge circuit with semiconductor strain gauges. Results. It is demonstrated that to reduce the multiplicative component of the temperature error in the output signal of the frequency integrating unfolding converter, it is proposed to use a temperature-dependent resistor for the integrator, made from the same semiconductor material as the strain gauges in the bridge circuit. The nominal resistance value and the temperature coefficient of resistance for the integrator resistor are determined iteratively based on the converter modeling results under the influence of elevated temperatures. Conclusions. Based on the calculations and modeling result’s analysis, it is concluded that the proposed technical solution is effective, since it allows to significantly reduce the additive and multiplicative components of the output signal error for frequency integrating unfolding converter.

The use of input devices of resonance-type in flaw detectors is advisable at frequencies above 100–200 kHz. However, in the practice of non-destructive testing by eddy currents, it is often necessary to use lower frequencies. In this case, one should connect the eddy current probes to devices with a non-resonant interface such as a bridge circuit. The functioning of bridge circuits used in eddy current sensors is significantly different from its functioning when used for components measurement because eddy current sensors operate under linear parametric modulation. In this case, it is advisable to perform the measurements by the self-comparison method, when a pair of closely located identical probes are placed in adjacent arms of the bridge. In this article, we first provide a detailed mathematical analysis of the operation of such a bridge circuit used as a flaw detector interface device. We use impedances of arbitrary finite values as disturbances. It is shown that despite the non-resonant character of the bridge circuit, it exhibits good selectivity for different loading (insertion) impedances. The isolines of the output signal and the probe's complex impedance diagram (hodograph) in balanced and imbalanced bridge circuits are jointly built. In this way, it is possible, for the first time, to construct hodographs in the complex plane for both selective signal suppression, and maximum sensitivity. Although this method is already used in series flaw detectors designed for aircrafts testing, the theory behind this method is presented here for the first time. [ABSTRACT FROM AUTHOR]

This article proposes an absolute-type inductive angle sensor for detecting the position of the YRT turntable bearing. The sensor comprises a multispeed incremental measuring unit and a single-speed absolute measuring unit sharing the same stator, rotor, and excitation circuit. The stator is composed of a ferromagnetic gear groove, two groups of excitation coils, and one group of induction coils arranged according to certain rules. The end cover of the YRT turntable bearing is machined as rotor and it rotated eccentrically relative to the rotation of the stator. A bridge circuit is used to acquire and process the sensor signal from the single-speed measuring unit. Compared with the traditional dual-channel absolute measurement, the proposed measurement method avoids the effects of different magnetic circuit disturbances on signal quality and measurement accuracy, and has more advantages in the volume and weight of the sensor. The structure and working principles of the sensor are presented in detail, the feasibility of sensing scheme is verified via simulation, and a sensor prototype is designed for the final experiment. Experimental results show that the accuracy of the sensor prototype is –0.06758° to 0.1203° before compensation and –0.001139° to 0.0015° after compensation in the range of [0°, 360°], respectively. [ABSTRACT FROM AUTHOR]

Magnetoresistive sensors are considered as part of bridge circuits for measuring magnetic field strength and electric current value. Normalized or relative expressions are introduced to change the resistance of the sensor and the measured bridge voltage to increase the information content of the regime to provide the possibility of comparing the regimes of different sensors. To justify these expressions, a geometric interpretation of the bridge regimes, which leads to hyperbolic straight line geometry and a cross ratio of four points, is given. Upon a change in the sensor resistance, the bridge regime is quantified by the value of the cross ratio of four samples (three characteristic values and the current or real value) of voltage and resistance. The cross ratio, as a dimensionless value, is taken as a normalized expression for the bridge voltage and sensor resistance. Moreover, the cross ratio value is an invariant for voltage and resistance. The proposed approach considers linear and nonlinear dependences of measured voltage on sensor resistance from general positions.Se analizează utilizarea senzorilor magnetorezistivi ca parte componentă a circuitelor în punte pentru măsurarea intensității câmpului magnetic și a curentului electric. Pentru a spori capacitatea informativă a regimului de lucru, a oferi posibilitatea de a compara regimurile diferitor senzori, sunt introduse expresii normalizate sau relative pentru schimbarea rezistenței senzorului și a tensiunii măsurate a punții. Pentru a fundamenta aceste expresii, se utilizează interpretarea geometrică a regimurilor de punte, ceea ce duce la geometria hiperbolică a liniei drepte și la raportul complex a patru puncte. Atunci când rezistența senzorului se schimbă, regimul de punte este determinat cantitativ de valoarea raportului complex a patru eșantioane (trei valori caracteristice și valoarea actuală) a tensiunii și rezistenței. Raportul complex, ca mărime adimensională, este luat ca expresie normalizată pentru tensiunea punții și rezistența senzorului. În plus, valoarea raportului complex este un invariant pentru tensiune și rezistență. Abordarea propusă ia în considerare, din punct de vedere general, dependențele liniare și neliniare ale tensiunii măsurate de rezistența senzorului.

Background. The purpose of the study is to calculate the parameters of the circuit of a frequency integrating unfolding converter to compensate for the temperature error resulting from the spread of the parameters of strain gages and the effects of elevated temperature. Materials and methods. Classical methods of semiconductor physics, semiconductor strain gauge and DC and AC electrical circuits are applied to calculate the dependence of the resistance of a semiconductor strain gauge on deformation and temperature and frequency of the voltage at the output of the FIUC. Results. It is found that in order to minimize the additive and multiplicative components of the error of the FIUC output signal, it is advisable to apply an original design solution for the bridge circuit, which consists in using a strain gauge with characteristics identical to those of semiconductor strain gauges, which will reduce the additive error of the output signal by more than 7 %. Conclusions. Based on the calculations carried out, it is concluded that this design solution is the optimal means of temperature compensation when the values of semiconductor strain gages of the FIUC bridge circuit are scattered, taking into account the technological features of semiconductor strain gages.

Theoretically, normally‐off silicon carbide (SiC) junction field‐effect transistors (JFETs) do not require a negative gate voltage supply because they are in an off‐state when the gate–source voltage is 0 V. However, most gate drivers for normally‐off SiC JFETs require not only a positive power supply for turning on the JFET but also a negative power supply for turning it off and maintaining a negative gate–source voltage to suppress a false turn‐on power loss caused by crosstalk during fast switching. Therefore, modifications of gate drivers increase complications and costs. In this study, a normally‐off SiC JFET gate driver, which can be realized using a simple circuit configuration with a single power supply, is proposed. To minimize undesirable crosstalk, the gate‐source voltage of the JFET is driven to a negative value and retained in the state for a long period of time. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

The paper presents principle scheme of wireless torque sensor on rotary shafts, for example truck cardan shaft, to measure dynamic torque of transmission in range of 0…10 kNm, also describes designing and manufacturing method. Recommendations on selecting, arranging and gluing strain-gauge in manufacturing, and on calculating signal amplifier are given. A simulation of sensor modules was carried out in software package Proteus to confirm working efficiency of assembled schema of electronic components. Experiment was conducted to confirm working efficiency and to collect performance specifications of the sensor.

The capacity of potentially inverse multielement two-terminal devices to become complementary two-terminal devices under conditions that differ from the condition of invertibility is well known. For such two-terminal devices, both the generalized (classical) condition of complementarity and particular conditions in the form of a group of mathematical expressions are satisfied. Examples of potentially inverse two-terminal devices of the other form, which theoretically cannot be inverse two-terminal devices, are also known. For these two-terminal devices, the generalized condition of complementarity cannot be satisfied. It has been established for such two-terminal devices that, when the generalized condition of complementarity is not satisfied, the group of particular conditions of complementarity holds true and they become pseudocomplementary two-terminal devices. The number of the particular conditions of complementarity equals the number of the elements in the potentially inverse two-terminal devices of two structures selected. The number of the elements in the two-terminal devices and their connection have been justified. Variants of using pseudocomplementary two-terminal devices based on potentially inverse two-terminal devices are presented. The former devices allow a reduction of the number of inverse model elements in bridge circuits, the grounding of all multielement two-terminal devices present in the bridge circuits, and the manufacture of bridges with extended functional capabilities. [ABSTRACT FROM AUTHOR]

In this paper, based on the previous research of our research team. We proposed a Vascular Interventional Surgical Robotic System based on Force-Visual feedback. In the process of vascular interventional surgery, it is very important to accurately detect the resistance force of surgical catheter, which can improve the safety of operation. Therefore, we developed a force sensor for the vascular interventional surgery robotic system based on the principle of resistance strain gauge bridge circuit. In addition, a complete robotic system with only force feedback is not enough. Therefore, it is necessary to combine the visual feedback interface to complete the operation. Finally, some verification experiments have been completed, including the evaluation experiment of the internal fixture of the force sensor, the calibration experiment of the force sensor, the evaluation experiment of the force sensor, the evaluation experiment of the force feedback, The axial and radial synchronous motion experiment between the master and slave side. Experimental results showed that the feasibility of the force sensor. Vascular Interventional Surgical Robotic System based on Force-Visual feedback has good performance of the force feedback and the synchronous motion between the master and slave side. There is a certain error in the synchronous motion between the master and slave side and the force feedback of the vascular interventional surgery robotic system based on Force-Visual feedback, the error is within the allowable range. [ABSTRACT FROM AUTHOR]

Aiming at the problems of low accuracy, long detection time and poor reliability of existing insulation detection system for electric vehicles, on the basis of studying the inherent mechanism of the measurement accuracy and reliability of insulation resistance for electric vehicles, replacing traditional electric relay by resistance partial measurement and optical control relay, an insulation resistance detection circuit of unbalanced bridge based on high-precision instrument amplifier was designed, then a four-step on-line calculation method of insulation resistance was proposed. Finally, a number of insulation resistance tests were completed for a light truck. The results showed that the detection system could achieve 5% insulation resistance measurement accuracy, and had the advantages of on-line detection and high reliability. [ABSTRACT FROM AUTHOR]

There are two kinds of electronic components—passive and active. One of the most used electrical components is diode, because of its ability to convert AC (alternate current) power supply into DC (direct current) for use in the daily life. A diode can be used as both full-wave and half-wave rectifier. Bridge circuit theory is commonly applied to full-wave rectifiers in soft computing engineering. This feasibility based on circuit simulation study aptly uses bridge circuit theory in a half-wave rectifier by replacing two diodes from a block with two resistors and providing only one positive input. The experimental results verify that the bridge circuit theory works fairly well with half-wave rectifier, and the output is the same as that of a simple half-wave rectifier circuit. [ABSTRACT FROM AUTHOR]

• New DSS_2CH high performance source developed at SUT was engaged to supply the bridge. • Nonlinearity errors of the main digitizer reaches a value higher than 10-5 but can be software corrected. • Validation results of the system demonstrate an uncertainty below 5 μΩ/Ω around 1 kHz for impedances with values from 100 Ω to 10 kΩ. • System is currently being implemented at Polish National Metrology Institutes. Digital impedance bridges are emerging as instruments suitable for the realization of impedance scale. The paper describes a new realization of a sampling-based four-terminal-pair electronic fully digital impedance bridge. Using a new high-performance source of digitally synthesized AC voltages, in conjunction with synchronous PXI sampling, the bridge can compare any two impedances across the entire complex plane in the frequency range of 20 Hz to 20 kHz. Operation of the bridge is validated using calibrated standards and the triangle method. Comparisons of calibrated standards and consistency checks performed at 100 Hz, 1 kHz and 1.59 kHz with impedances in the range from several hundred Ω to several kΩ demonstrate that the bridge has an accuracy better than 10-5. We discuss the uncertainty of the bridge in more detail and specifically measure the main digitizer nonlinearity errors which limit the accuracy of the bridge for 1: n comparisons. In the future, the accuracy of the bridge could be improved by correcting for this nonlinearity. [ABSTRACT FROM AUTHOR]

At the National Metrology Institute of Japan, we are developing a transformer bridge circuit that can precisely compare the i = 2 plateau resistance in an ac quantized Hall resistance with a 100-k \Omega resistance. In this paper, we propose a practical transformer voltage ratio of 7.75:1, which is the most important parameter for developing a transformer bridge circuit. Further, we describe the design of an inductive voltage divider (IVD) to realize the 7.75:1 ratio. We intend to use the proposed IVD as a reference standard for calibrating the voltage ratio of the transformer. The reference IVD was fabricated with the two-stage technique and calibrated by Thompson’s method. The deviation from the nominal ratio of 7.75 was estimated to be -5.92 \times 10^\mathrm -6 for in-phase and -22.75\times 10^\mathrm -6 for quadrature. The standard uncertainty of this calibration was estimated to be 0.63\times 10^\mathrm -6 for in-phase and 6.28\times 10^\mathrm -6 for quadrature. [ABSTRACT FROM PUBLISHER]

We have developed a binary compensation unit for balancing measurement bridges with cryogenic current comparators (CCCs) commonly used in resistance metrology. We present the basic design ideas for the new microcontroller-operated module. It offers balance over a gapless range of resistance ratios of the resistors to be compared. The binary setup allows for convenient calibration when being combined with a binary CCC. The calibration can be performed using the CCC's control electronics and software. Examples of measurements demonstrate the unit's high flexibility and stability of resistance calibration well below one part in 10^9 over a period of 21 hours. [ABSTRACT FROM PUBLISHER]

The method is suggested for measurement of dynamic strains by using resistance strain gauges. The working power is supplied by the generator of DC pulses with a voltage of 23 V and duration of 14 ms. The short-time supply of the power allows increasing the working current from 25-50 to 200-250 mA, this leading to almost an order of magnitude increase in sensitivity of the method. The measurement system comprises the DC pulse generator and the digital oscillograph connected to a computer. Calibration tests were carried out, and performance of the measurement system was investigated in a range of elastic and elasto-plastic strains. It is shown that the dynamic strains due to explosion loading of metal structures can be measured at a satisfactory accuracy within -0.6-0.6 % in a time interval of 0-14 ms. In addition, the system makes it possible to fix residual strains of metal of a structure after the dynamic impact. [ABSTRACT FROM AUTHOR]

A method of designing a measuring temperature converter using an automatic voltage compensator based on the use of an operational amplifier and a bridge circuit with two power-supply diagonals is considered. The proposed procedure enables the nominal values of all the resistors to be determined from the conditions for obtaining specified characteristics of the measuring temperature converter. [ABSTRACT FROM AUTHOR]

A novel variable inductor using a bridge circuit is proposed. Because of a bypass switch MOSFET placed at a balance point, the effect of the switch resistance which is a penalty of the variable inductance is suppressed and degradation of the Q factor is mitigated. [ABSTRACT FROM AUTHOR]

Introduces a temperature acquisition system based on AW60. The system consists of temperature acquisition circuit based on PT100 platinum RTD (Resistance Temperature Detector) the bridge circuit amplification circuit and AW60 minimum system. The bridge circuit is used to correct the acquisition signal and amplification circuit based on TL062 chip can amplify this correction signal, which not only can eliminate difference of resistance stemmed from PTI00 lead wire difference, but also amplify acquisition signals by operational amplifier to overcome small range in changing the resistance of PT100. In this design we design hardware according to the AD (Analog Digital) conversion interface integrated in AW60. At the same time, we also illuminate software designing of the system the test results and the experience of the design process which guides other designers to design temperature collection systems based on 8-bit MCU made by Freescale's company. [ABSTRACT FROM AUTHOR]

This paper describes a new features of resistance bridge supplied by two current sources placed in opposite arms. The possibility to simultaneous measurements of temperature and strain has been achieved by using this technique and it is described with some theoretical considerations. Theory is mentioned along with data to confirm that the temperature and strain gauge resistance changes are sensed without appreciable error. Also the results of an experiment confirm this approach. To complete these considerations the uncertainty of both temperature and strain changes is calculated. Also the possibility to apply this technique in biomechanics is discussed. [ABSTRACT FROM AUTHOR]

Systems and structures monitoring their own structural integrity have become an active field. One method uses the piezoelectric impedance-based structural health monitoring technique (SHM), which utilizes a piezoelectric patch attached to a structure and measures its impedance within a certain frequency range. The frequency is maintained in the kiloHertz range for optimum sensitivity and coverage in damage detection. Owing to the coupling between electrical impedance and mechanical impedance, electrical impedance variations can indicate physical changes in the host structure. Based on the idea of a bridge circuit, a new electronic circuit to realize electrical impedance monitoring is presented (US patent pending). The proposed circuit generates a frequency sweep from 53 to 164 kHz and measures the relative value of the electrical impedance modulus of a piezoelectric patch. The circuit can be integrated into a chip combined with a piezoelectric patch attached to a structure. With the help of a communication circuit, a remote SHM system can be set up in the future. [ABSTRACT FROM AUTHOR]

Abstract: Microcantilever with embedded piezoresistor has been applied to in situ surface stress measurement of biochemical reaction, where the parallel microcantilever by using an active cantilever for biosensing and another reference cantilever for noise cancellation has previously been proposed. This paper shows that the microcantilever measurement is sensitive to the temperature effect induced by the piezoresistor. The two cantilevers of 125μm×60μm×0.75μm may have 40°C temperature difference, 1.65mV offset voltage, and 0.01mV/°C temperature drift in 10V operation because of their different thermal inertia. A parallel microcantilever design is developed for temperature compensation by using a signal conditioning circuit and the stripe pattern immobilized layer. Analyses and experiments show that the performance of parallel microcantilever sensor can be significantly improved. [Copyright &y& Elsevier]

This paper describes the development and evaluation of a custom-built impedance analyzer, which uses a multiplexing bridge circuit to characterize an array of polymer-coated quartz crystal microbalance (QCM) sensors. The analyzer is constructed on a single printed circuit board with minimum components and is sufficiently compact for integration into a handheld format. The custom-built device is used to observe the changes that occur in QCM sensors when experimental conditions such as polymer coating film thickness, odorant vapor pressure, and relative molecular mass are varied. An equivalent electric circuit for a QCM is used to model the conductance and susceptance data captured by the analyzer. The measured response of an array of QCM sensors demonstrates that the custom-built device is a suitable instrument for detecting different gases and understanding polymer-vapor interactions [ABSTRACT FROM PUBLISHER]