Search results for "CIRCUIT"
showing 10 items of 936 documents
Approach to the analysis of nonlinear feedback oscillators under large-signal injection
1986
A method for the analysis of driven oscillators under high-level injection is presented. It applies to single-loop feedback systems with a memoryless nonlinear element and a second-order (high-Q) tank circuit. The analysis technique employed combines the classical block-diagram approach with an improved firstharmonic dynamic modelling to provide a couple of differential equations capable of accounting for the amplitude-dependence effects arising under large-signal operation. On this basis, first-and second-order approximate expressions are also derived, which allow a better understanding of the validity limits of previous theories on this subject. As an example of application, both the stea…
Analysis of bias-shift effects in free-running and injection-locked negative resistance oscillators
2012
In this paper, the interaction between DC and RF in quasi-sinusoidal free-running and injection-locked oscillators is addressed. To account for and illustrate in a user-friendly manner the bias-shift related effects stemming from such interaction, a frequency-domain method of analysis has been developed for a rather wide class of negative-resistance circuits. Grounding on a first-approximation exact perturbation-refined approach, it permits computationally efficient simulation of the oscillator behavior directly in terms of the DC and RF signals evolutions (dynamical complex envelopes). In fact, it allows the investigation of both steady-state and transient operation of the shifting-bias dr…
Parameter identification of linear induction motor model in extended range of operation by means of input-output data
2012
This paper proposes a technique for the off-line estimation of the electrical parameters of the equivalent circuit of linear induction machines (LIM), taking into consideration the end effects, and focuses on the application of an algorithm based on the minimization of a suitable cost function involving the differences of measured and computed by simulation inductor current components. This method exploits an entire start-up transient of the LIM to estimate all the 4 electrical parameters of the machine (Rs, L s, σ Ls, Tr). It proposes also a set of tests to be made to estimate the variation of the magnetic parameters of the LIM versus the magnetizing current as well as the magnetizing curv…
Evaluation of an Alternative for Increasing Switch Radix
2011
In large switch-based interconnection networks, increasing the switch radix results in a decrease in the total number of network components. In this paper we evaluate an interesting strategy for building high-radix switches going beyond the integration scale bounds. This approach is independent of the evolution of single-chip switches and will remain valid as integration scale keeps evolving. Simulation results show that with a correct internal switch design, this kind of switches achieves almost the same performance as single-chip switches with the same radix, which would be unfeasible with current integration scale.
Advanced Monitoring Systems Based on Battery-Less Asset Tracking Modules Energized through RF Wireless Power Transfer
2020
Asset tracking involving accurate location and transportation data is highly suited to wireless sensor networks (WSNs) featuring battery-less nodes that can be deployed in virtually any environment and require little or no maintenance. In response to the growing demand for advanced battery-less sensor tag solutions, this article presents a system for identifying and monitoring the speeds of assets in a WSN with battery-less tags that receive all their operating energy through radio frequency (RF) wireless power transfer (WPT) architecture, and a unique measurement approach to generate time-domain speed readouts. The assessment includes performance characteristics and key features of a syste…
‘Dry’ electrochemistry: A non-invasive approach to the characterization of archaeological iron objects
2021
A methodology for monitoring the corrosion state of archaeological iron objects using ‘dry’ open circuit potential (OCP) measurements is described. Application of this technique to a set of objects from La Bastida de les Alcusses archaeological site (Moixent, València, Spain), dating back to the 4th century BCE, reveals significant differences depending on the conservation state. The transient OCP responses (which last between a few seconds and 10–15 min) were superimposed with much shorter (less than one second) intense features. Fil: Doménech Carbó, Antonio. Universidad de Valencia; España Fil: Peiró Ronda, María Amparo. Museu de Prehistòria de València; España Fil: Vives Ferrándiz, Jaime…
Un circuit automobile au cœur d’une métropole ? Les Circuiti et Gran Premi du Valentino (1935-1955)
2022
De 1935 à 1955 sont disputées de manière intermittente dans le parc du Valentino, des courses de monoplaces qui prennent le nom de « Circuit » ou de « Grand Prix ». Dans la cité de l’automobile, la compétition prend des significations différentes : vitrine du culte de la vitesse fasciste et du passé glorieux de Turin en 1935 et 1937, symbole de la renaissance de l’Italie républicaine et du rapprochement de la France en 1946, 1947 et 1948, manifestation du désir de mobilité automobile en 1952 et 1955. L’organisation d’une course au sein du poumon vert d’une métropole constitue aussi un défi : celui de l’ordre public, de la sécurité, des dégradations, du couvert végétal. Aussi, même si la cou…
La distribution : organisation et stratégie
2020
Croissance rapide de nouvelles formes de vente, stratégies de mutualisation des ressources logistiques, phygitalisation, plateformisation, politique de réenchantement des points de vente... Autant de bouleversements du paysage économique qui font désormais de la distribution une fonction clé de la gestion des entreprises. Comprendre et expliquer à la fois sa dynamique et ses enjeux revêt, à ce titre, une importance majeure. Rédigé par trois spécialistes reconnus du sujet, l'ouvrage se fixe pour objectif d'aborder de façon pédagogique les principales dimensions de la distribution : la relation avec l'acheteur final, la gestion des interfaces entre industriels et distributeurs, et les enjeux …
Progress towards innovative and energy efficient logic circuits
2020
Abstract The integration of superconductive nanowire logic memories and energy efficient computing Josephson logic is explored. Nanowire memories are based on the integration of switchable superconducting nanowires with a suitable magnetic material. These memories exploit the electro-thermal operation of the nanowires to efficiently store and read a magnetic state. In order to achieve proper memory operation a careful design of the nanowire assembly is necessary, as well as a proper choice of the magnetic material to be employed. At present several new superconducting logic families have been proposed, all tending to minimize the effect of losses in the digital Josephson circuits replacing …
Kramers–Kronig transformation, dc behaviour and steady state response of the Warburg impedance for a disk electrode inlaid in an insulating surface
2002
Abstract As the frequency approaches zero, the impedance described by the Warburg function tends to infinity. This means that the resistance of the equivalent circuit representing the electrochemical process has an infinite resistor and then the current cannot flow through it. This asymptotic behaviour also prevents the application of the Kramers–Kronig transformations, a set of integrals which should be fulfilled by any linear system. Using a more general expression of the impedance for a disk electrode inlaid in an insulating surface developed by Fleischmann and Pons (J. Electroanal. Chem. 250 (1988) 277), the Warburg impedance can be deduced and the Kramers–Kronig transformation is possi…