Single Resistor Research Articles

Cell Membrane Potential Model Circuit Lab

There remains a strong movement for Introductory Physics for Life Sciences (IPLS) courses to better integrate physics and biology. Part of the challenge for IPLS educators is to introduce fundamental physical law while simultaneously establishing the relevance of physics to biological science. Life science relevant laboratory experiences are essential to the training of future biologists and health professionals. The physiology of neurotransmission can be especially challenging to life science majors, but may be somewhat clarified in the IPLS course by model circuit labs. A realistic axon model lab using rubber tubing and gelatin recently reported by Dyer highlights the motivational value of lab experiences bridging biophysics and neurophysiology. Time-independent and time-dependent circuit labs modeling passive spread of charge within an axon absent the action potential have been described. In this paper, we describe a progressive complex circuit lab sequence introducing students to Kirchhoff’s rules, a model of the cell membrane resting potential, and a model representing key features of the action potential in an axon. In this context, “complex” describes a circuit that cannot be reduced to a single battery and resistor.

A Generalized 3-dB Wilkinson Power Divider/Combiner With Complex Terminations

A generalized 3-dB isolated three-port power divider/combiner is presented. The termination impedances of the two electrically isolated ports are selected as equal complex values of choice. The termination impedance of the third port can be selected as any complex value independent of the other two ports. The presented design equations show a broad continuum of solutions where existing solutions are subsets. The generalized power divider/combiner can be synthesized with lumped elements and/or transmission lines, resulting in a practical and compact circuit. The increased design flexibility of the generalized power divider enables, for example, direct integrated matching to 50 $\Omega $ at the input port, direct integrated complex matching at the other two ports, and a single resistor with physical isolation as the isolation branch. This particular example is experimentally verified through fabrication and measurements of a 2-GHz divider.

Electronically tunable high gain current-mode instrumentation amplifier

A new design for electronically tunable current mode (CM) instrumentation amplifier (IA) is presented in this paper. It employs Modified Z copy Current Differencing Transconductance Amplifier (MZC-CDTA) along with a resistor. The gain of the proposed CM IA is controlled by a single resistor and can theoretically approach infinite value. Electronic tuning feature is augmented by using a MOS based resistor. The functionality is verified through simulations on Cadence Virtuoso using TowerJazz’s 180 nm Technology Node and performance against PVT variations is also examined. Feasibility of on-chip implementation is confirmed by the post-layout simulations carried out.

Performance of a Distributed Dynamic Brake for an Induction Motor Fed by a Modular Multilevel DSCC Inverter

This paper provides an experimental and theoretical discussion on dynamic braking for a medium-voltage induction motor fed by a modular multilevel double-star chopper-cell (DSCC) inverter. It is intended to apply the motor drive to large-capacity fans and compressors with a large moment of inertia. Each chopper cell consists of a bidirectional chopper and a braking chopper connecting a single small-rated braking resistor in series with a single IGBT. This configuration results in a “distributed” dynamic brake that provides a distinctive welcomed side effect of protecting all the bidirectional-chopper cells against sudden overvoltage. An experimental system rated at 400 V and 15 kW is designed, constructed, and tested to verify operating performance of the distributed dynamic brake. Experimental waveforms, along with simulated waveforms, confirm firmly that the distributed dynamic brake is feasible and effective in an induction motor fed by a medium-voltage high-power DSCC inverter for fans and compressors. Finally, this paper gives a design example of a distributed dynamic-braking resistor for the 11-kV, 12-MW induction motor driving a large-capacity fan equipped with a large moment of inertia.

Wideband bandpass‐to‐all‐stop reconfigurable filtering power divider with bandwidth control and all‐passband isolation

A novel wideband bandpass-to-all-stop reconfigurable filtering power divider is proposed in this study, which allows for four-order bandpass-to-all-stop reconfigurable operating function and equal power division. Its circuit configuration includes the cascaded coupled-line sections with tight coupling to extend the impedance transforming. Furthermore, with the introduction of the half-wavelength open-circuit stubs, which controls the bandwidth, extra transmission poles located at the cut-off frequency are generated, thus resulting in high frequency selectivity. Moreover, by using a single resistor between input coupled-lines, the high all-passband isolation can be achieved. The grounding are then loaded to the output coupled-lines to enable bandpass-to-all-stop operating functionality. For demonstration, a prototype operating at 2 GHz is designed, simulated, and measured with a 15 dB bandwidth of 51%, 19 dB stopband rejection up to 5 GHz, and 14.5 dB all-passband isolation, which shows a good agreement between the simulated and measured results.

Spoof Surface Plasmon Polaritons Power Divider with large Isolation

Periodic corrugated metal structure is designed to support and propagate spoof surface plasmon polaritons (SSPPs) wave in the microwave frequencies. In this paper, firstly a plasmonic waveguide consisting of oval-ring shaped cells is proposed with the performance of high transmission efficiency in a wide frequency range. The coplanar waveguides (CPWs) with 50 Ω impedance are adopted to feed the energies or extract signals at both ends of the plasmonic waveguide. Then a well-isolated power divider is constructed based on the SSPPs waveguides aiming to equally split the energy of the SSPPs wave into two equal parts. The stepped-impedances are co-designed with the three input/output ports of the power divider to achieve the impedance-matching between the SSPPs waveguides and the coplanar waveguides. Besides, a single resistor is placed in the middle of two symmetrical half oval-rings to realize the isolation between the two output ports over the spectrum of 4.5–7.5 GHz. Finally, both plasmonic waveguide and the power divider are fabricated and tested to verify the predicted characteristics.

Electronically Controllable Sinusoidal Oscillators Employing VDIBAs

Two new electronically controllable sinusoidal oscillators each employing two Voltage Differencing Inverting Buffered Amplifiers (VDIBAs), two capacitors, and a single resistor have been proposed. The presented oscillators offer independent electronic control of Condition of Oscillation (CO) and Frequency of Oscillation (FO), and low active and passive sensitivities. The effect of non-idealities of the VDIBAs on the proposed oscillators is also investigated. The validity of the proposed structures has been confirmed by SPICE simulation with TSMC 0.18 µm process parameters.

Improved Distribution of Resistance Switching Through Localized Ti-Doped NiO Layer With InZnOx/CuOx Oxide Diode

Asymmetric sized single oxide diode (InZnOx/CuOx) with single resistor (Ti-doped NiO) device (1D-1R) was integrated into a crossbar array at room temperature to provide high current through the diode while keeping resistance switching localized in a small area. The Ti (0.1 wt %) doped NiO layer was fabricated inside an inverted cone-structure to localize switching and improve general device performance. We were able observe resistance switching up to around 100 cycles in the 1D-1R structure. In addition, the addition of the diode to the structure acted as an external resistance suppressing overflow current during Ti-doped NiO switching from a high resistance state to a low resistance state, thus improving switching distribution in both low (average = $3.2\times 10^{-5} \Omega $ , standard deviation = $1.3\times 10^{-6} $ ) and high (average = $2.8\times 10^{-6} \Omega $ , standard deviation = $6.7\times 10^{-7}$ ) resistance states.

Mathematical simulation of thermal state of digital current and voltage transformer in unfavourable weather conditions

This study examines issues relating to heat exchange between an innovative 6(10) kV current and voltage transformer (and its components) and its environment in unfavourable weather conditions. Existing designs of digital current and voltage transformers are featured in systems of commercial and technical electric power accounting, and also relay protection and automation. We have presented the results of mathematical simulation of the thermal state of both a single resistor included in our measuring device, and the digital transformer as a whole. Simulation was performed using the finite element method. We have taken into account the impact of such factors as direct and diffused solar radiation, high ambient temperatures and various voltage levels on the thermal state of the functioning equipment. To verify the developed mathematical model we have presented the results of a series of experiments conducted in a high-voltage environmental chamber. Our study conclusively shows that voltage, insolation and ambient temperature significantly affect the thermal state of a functioning current and voltage transformer.

Investigation on the AC and DC electrical conductivity of Sn3Sb2S6 thin films prepared by glancing angle deposition

Sn3Sb2S6 thin films were deposited by single source vacuum thermal evaporation using glancing angle deposition technique. The incident angle α between the particle flux and the normal to the substrate was varied from 0° to 85°. The structural, morphological and electrical properties were investigated by X-ray diffraction, scanning electron microscopy, and impedance spectroscopy, respectively. The effect of these properties as a function of the incident angle has been studied. The AC conductivity exhibited a Jonscher’s universal power law. It is observed that exponent s decreases with increasing measurement temperature. Further analysis revealed that, samples AC conductivity follows the correlated barrier hopping model. The Cole–Cole plot showed a single semicircle, indicating an equivalent circuit with a single parallel resistor R and capacitance C network. The activation energy obtained from both angular relaxation frequency and DC conductivity suggests that the carrier transport mechanism is a hopping mechanism thermally activated in the band gap.

Generalized Dual-Band Unequal Filtering Power Divider With Independently Controllable Bandwidth

In this paper, a novel design method of generalized dual-band unequal filtering power divider (DUFPD) is proposed. Using this method, the power divider (PD) could be designed to realize the dual-band filtering response with arbitrary power division, arbitrary frequency ratio, arbitrary real terminated impedances, independently controllable bandwidth, and excellent isolation. To satisfy these characteristics, a proper dual-band filtering structure is selected to replace the conventional quarter-wave length transmission line in the PD. In addition, a single resistor structure is utilized to obtain effective isolation between the output ports. Furthermore, the complete design procedures and analytical equations of the proposed generalized DUFPD are presented based on the circuit and transmission line theories. To demonstrate the validity of the proposed design method, a DUFPD with different real terminated impedances is designed, fabricated, and measured. We show that there is a good agreement between the simulated and measured results.

Universal Filter Using Single Commercially Available IC: LT1228

In electrical and electronic engineering, the filter is very importance circuit. A voltage-mode three inputs single output second-order multifunction filter is presented in this paper. The proposed filter is based on RLC parallel circuit. The main active element is the commercially available IC from Linear Technology Inc, LT1228. The filter consists of single LT1228, single resistor and two capacitors. Five output second-order filter responses, namely band-pass (BP), band-stop (BS), high-pass (HP), low-pass (LP) and all-pass (AP) functions are achieved. Each output response can be selected without component matching condition and the requirement of double gain amplifier. The quality factor and natural frequency can be electronically controlled. PSpice simulation results suing macro model of LT1228 are in close agreement with the theory.

Two New Single-Resistor-Controlled Quadrature Sinusoidal Oscillators using Current-Differencing-Buffered-Amplifiers

Two new single resistor–controlled quadrature oscillator (SRCQO) circuits using only two current differencing buffered amplifiers (CDBAs) as active elements and only three resistors and two capacitors, are presented. First proposed circuit uses all input terminals of the CDBA to exploit full capacity of the CDBAs, offers better sensitivities with respect to active parameters and has wide frequency range of operation. The second proposed circuit provides very good low frequency performance with respect to total harmonic distortion. Separate single resistors can control both oscillation condition and the oscillation frequency of the proposed quadrature oscillator circuits independently. PSPICE simulation results based upon commercially available AD844 ICs, to construct the CDBAs, are included which confirm the practical workability of the new proposed quadrature oscillator circuits.

Impedance and ionic conduction of single crystalline BaTi2O5

Electrical properties of single-crystalline BaTi2O5, prepared by a floating zone method, were examined by AC impedance spectroscopy at frequencies of 10−2 to 106 Hz at temperatures of 425–970 K. Complex impedance in a direction perpendicular to (001) was exhibited by a single resistor (R)–capacitor (C) parallel circuit. In the direction perpendicular to (010), four R–C parallel circuits were involved: two R–C circuits were associated with a strong temperature-dependent ferroelectric response and a slightly temperature-dependent paraelectric response, while the other two R–C circuits corresponded to the interface phenomena associated with ionic conduction. The electrical conductivity in the direction perpendicular to (010) was one-to-three orders of magnitude higher than that in the direction perpendicular to (001).

Investigation of physico-chemical properties of conductive Ga-doped ZnO thin films deposited on glass and silicon wafers by RF magnetron sputtering

We report on the physico-chemical properties of Undoped and Ga-doped ZnO films fabricated on glass and p-Silicon wafers at room temperature by RF magnetron sputtering using a ZnO and Ga2O3 mixture raw powder target without sintering procedure. X-ray diffraction (XRD) and energy dispersion spectroscopy (EDS), scanning electronic microscopy, Raman scattering, ultraviolet–visible spectroscopy, photoluminescence (PL), Hall effect and impedance spectroscopy technique have been applied for the comparative study of ZnO and ZnO:Ga thin films. XRD and Raman studies have shown that the deposited films have a preferred orientation growth with Ga atoms both in substitutional and interstitial positions. EDS analyses have allowed to show that the metallic Ga atoms have been incorporated in the ZnO films. Doping by gallium resulted in a slight increase in the optical band gap energy of the films while the optical transmittance remains about 80 %. The PL analysis at room temperature revealed violet, blue, green and red emissions. Room temperature Hall measurements show that the lowest resistivity was 3.40 × 10−4 Ω cm with an electron mobility of 18.56 cm2/V.s for an optimum Ga concentration of 4 wt%. Impedance spectroscopy study showed that σac obeys the relation \(\sigma_{ac} = A\omega^{s}\). The exponent ‘‘s’’ was found to decrease with increasing the temperature. It is found that, the AC conductivity of all samples follow the correlated barrier hopping model. The Nyquist plots showed a single semicircle, indicating an equivalent circuit with a single parallel resistor R and capacitance C network. The values of the activation energy E a deduced from both DC conductivity and relaxation frequency for all the studied samples ranged from 0.51 to 0.73 eV and the results are explained on the basis of the induced defects due to the addition of Ga into the ZnO films.

Highly Sensitive NO2 Detection and DMP Sensing at Room Temperature using Flexible SWNT Thick Film Sensor

<p class="p1"> </p><p class="p2"><span class="s1"> </span>Low cost; easy to fabricate and flexible single wall carbon nanotubes thick film resistor (SWNT-TFR) for detailed study of NO<span class="s2">2 </span>detection is reported. SWNT-TFR was fabricated by vacuum filtration technique on flexible polycarbonate membrane. SWNT-TFR sensor shows selective response to NO<span class="s2">2</span>. The response increases from 1.47 per cent to 17.34 per cent with increasing the NO<span class="s2">2 </span>concentration from 0.2 ppm to 10 ppm, respectively. Different energy sources, IR, thermal and UV were explored for achieving fast recovery of the SWNT-TFR sensor. The results showed that the gas sensor gives immediate and fast recovery in the presence of UVC light. The calculated detection limit is less than 764 ppt for NO<span class="s2">2</span>. We are also presenting sensing of dimethyl methylphosphonate (DMMP) as a simulant of sarin. SWNT-TFR gives repeatable response of ~2.7 per cent for 500 ppm of DMMP. This work suggests the possibility to utilise SWNTs-TFR as NO<span class="s2">2 </span>sensors for air-quality monitoring. </p>

Wideband Filtering Power Divider With Ultra-Wideband Harmonic Suppression and Isolation

In this paper, a wideband filtering power divider (PD) with ultra-wideband harmonic suppression and isolation is proposed. The dual coupled-line sections are embedded to the conventional quarter-wavelength transmission lines, which helps to extend the passband of the PD. With the introduction of the short-circuit stubs shunted at the output ports and the coupled lines with the open-circuit stubs, the ultra-wide stopband can be implemented more efficiently, thus resulting in five transmission zeros from 2 to 6 GHz. Furthermore, the improved isolation structure with series connected a resistor and a capacitor can be utilized to realize the ultra-wide isolation frequency band. Using a single resistor between two output ports, we have achieved an excellent in-band isolation. For demonstration, a wideband filtering PD operating at 1 GHz with a 20-dB bandwidth of 50% and an ultra-wide stopband better than 20 dB from 2 to 6 GHz is designed, fabricated, and measured. The measured results agree well with the anticipation.

A memristor-based Wien-bridge sinusoidal/chaotic oscillator

This paper presents the experimental results obtained from a memristor-based Wien-bridge oscillator implemented using a new memristor emulator. The memristor emulator can be implemented using off-the-shelf components. The experimental results show that nonlinear chaotic as well as linear oscillations can be obtained from the same circuit by careful adjustment of the value of a single resistor. The proposed circuit can be easily presented in an undergraduate laboratory course to demonstrate the use of memristors in generating chaotic oscillators.

Temperature Errors in Linearizing Resistance Networks for Thermistors

It is well known that a single negative-temperature-coefficient thermistor can be linearized over a narrow temperature range by connecting a single resistor in parallel with the thermistor. With the linearizing resistor properly chosen for the operating temperature, the residual errors are proportional to the cube of the temperature range and have a peak value of about \(0.2\,^{\circ }\hbox {C}\) for a \(30\,^{\circ }\hbox {C}\) range. A greater range of temperatures can be covered or greater linearity be achieved by cascading thermistor–resistor combinations. This paper investigates the limits of the linearity performance of such networks by using interpolation to model their behavior. A simple formula is derived for estimating the residual non-linearity as a function of the number of thermistors, the temperature range covered by the network, and the constant characterizing the exponential temperature dependence of the thermistors. Numerical simulations are used to demonstrate the validity of the formula. Guidelines are also given for circuit topologies for realizing the networks, for optimizing the design of the networks, and for calculating the sensitivities to relative errors in the component values.

Microcrystalline silicon: Strain gauge and sensor arrays on flexible substrate for the measurement of high deformations

This paper presents strain sensor arrays on flexible substrates able to measure local deformation induced by radii of curvature of few millimeters. Sensors use n-type doped microcrystalline silicon (μc-Si) as piezoresistive material, directly deposited on polyimide sheets at 165°C. Sensitivity of individual sensors was investigated under tensile and compressive bending at various radii of curvature, down to 5mm. A Transmission Line Method was used to extract the resistivity for each radius. The devices exhibited longitudinal gauge factors of −31 and longitudinal piezoresistive coefficients of −4.10−10Pa−1. Reliability was demonstrated with almost unchanged resistances after cycles of bending (standard deviation of 1.7%). Strain gauge arrays, composed of 800 resistors on a 2cm2 area, were fabricated with a spatial resolution of 500×500μm2. Strain mapping showed the possibility to detect local deformation on a single resistor or to detect larger objects. These strain sensor arrays can find applications when high sensitivity and high spatial resolution is required. This paper also showed that μc-Si can be a relevant semi-conductor candidate for flexible electronics.