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Electronic Circuits (electronic + circuit)
Selected AbstractsView of Technical Committee on Electronic Circuits on the progress of electronic circuit technologies in the past decade and the future prospectsIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 1 2009Shigetaka Takagi No abstract is available for this article. [source] Comments on the IPC Surface Mount Attachment Reliability GuidelinesQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 4 2005Olli Salmela Abstract The Institute for Interconnecting and Packaging Electronic Circuits (IPC) has published guidelines and standards related to surface mount solder attachments. The latest standard IPC-9701 was published in 2002. In this paper, the general methodology for creating the aforementioned documents and the related qualification requirements are reviewed and discussed. Also, corrections to the standards and guidelines are proposed. The corrections are related both to the use of formulas and to inaccuracies in the units used. Copyright © 2005 John Wiley & Sons, Ltd. [source] Field measurements of the water content in the top soil using a new capacitance sensor with a flat sensitive volumeJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 2 2005Bernhard Ruth Abstract Water content directly near the soil surface plays an essential role for degradation of natural organic material and agrochemicals by soil microbes. Furthermore, the water losses by evaporation depend sensitively on the top-soil water content. Rain, irrigation, evaporation, and the water flow between the soil horizons together with the natural inhomogeneity of soils cause a high spatial gradient and a pronounced time dependence of the water content in the top soil. To understand processes in top soil such as redox gradients, the knowledge on ecological conditions in the top soil, which is subject to rapid changes, is essential. In order to meet the requirements for such field measurements, a capacitance sensor with a depth resolution of 1,cm and an active area of 7.5,cm × 14,cm was constructed and operated by a special electronic circuit. Field measurements using these sensors at 1,cm depth showed the high dynamics when measurements were carried out every 10,min. As simultaneous measurements of the soil temperature at 1,cm depth exhibit large temperature variations during the day, its influence on the measurements must be compensated for. As the data, measured during drying periods, allow the assessment of the temperature coefficient, the water content at a reference temperature can be calculated. The course of the water content reflects precipitation events and quantifies the drying of the soil, providing these parameters for process evaluation. Furthermore, the diurnal variation exhibits the drying during the day and the possible rewetting from deeper horizons during the night. Freilandmessungen des Wassergehalts im Oberboden mit einem neuen Kapazitätssensor mit flachem sensitiven Volumen Der Wassergehalt direkt an der Bodenoberfläche spielt für den mikrobiellen Abbau natürlicher organischer Substanz und von Agrochemikalien eine bedeutende Rolle. Darüber hinaus hängen die Wasserverluste durch Evaporation empfindlich vom Wassergehalt an der Bodenoberfläche ab. Regen, Bewässerung, Evaporation und die Wasserbewegung zwischen den Bodenhorizonten, sowie die natürliche Inhomogenität des Bodens verursachen einen großen Gradienten und eine ausgeprägte Zeitabhängigkeit des Wassergehalts und entsprechender Stofftransformationsprozesse im Oberboden. Für das Verständnis der Prozesse im Oberboden, wie z.,B. der Redox-Gradienten, ist die Kenntnis der ökologischen Bedingungen in dem sich schnell verändernden Oberboden unerlässlich. Um die Anforderungen für solche Feldmessungen zu erfüllen, wurde ein Kapazitätssensor mit einer Tiefenauflösung von 1,cm und einer aktiven Fläche von 7.5,cm × 14,cm konstruiert und mit einem speziellen elektronischen Schaltkreis betrieben. Feldmessungen in der Tiefe von 1,cm zeigen eine große Dynamik, wenn alle 10 min ein neuer Messwert erfasst wird. Da simultane Messungen der Bodentemperatur in 1,cm Tiefe hohe Variationen zeigen, muss deren Einfluss auf die Messung kompensiert werden. Da die Messungen während der Trockenperioden die Abschätzung des Temperaturkoeffizienten erlauben, kann der Wassergehalt bei einer Referenztemperatur errechnet werden. Die Messergebnisse korrespondieren mit Regenereignissen und erfassen die Austrocknung des Bodens, so dass damit Parameter für die Prozessberechnung zur Verfügung gestellt werden. Der Tagesgang zeigt Austrocknung während des Tages und die mögliche Wiederbefeuchtung aus tieferen Horizonten während der Nacht. [source] An educational tool for power electronics circuitsCOMPUTER APPLICATIONS IN ENGINEERING EDUCATION, Issue 1 2010Cetin Elmas Abstract In this study, an educational tool has been prepared for a shorter term and more economic education of power electronics circuits. In parallel with the improvements of semiconductor technology, the development of power electronics circuits has magnified the importance of either teorical or practical education of power electronics course. The education of power electronic circuits in laboratory is an agelong, costly piece of work. In this study, to overcome the mentioned negativities, a tool has been prepared for the education of power electronic circuits. The tool, which has been prepared on C++ Builder environment has a flexible structure and a graphical interface. It has enabled the analysis of working principles of the circuits and traceability of the system response by the help of graphics, under different conditions created by changing the values of circuit elements. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 157,165, 2010; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20237 [source] Foldable Printed Circuit Boards on Paper SubstratesADVANCED FUNCTIONAL MATERIALS, Issue 1 2010Adam C. Siegel Abstract This paper describes several low-cost methods for fabricating flexible electronic circuits on paper. The circuits comprise i) metallic wires (e.g., tin or zinc) that are deposited on the substrate by evaporation, sputtering, or airbrushing, and ii) discrete surface-mountable electronic components that are fastened with conductive adhesive directly to the wires. These electronic circuits,like conventional printed circuit boards,can be produced with electronic components that connect on both sides of the substrate. Unlike printed circuit boards made from fiberglass, ceramics, or polyimides, however, paper can be folded and creased (repeatedly), shaped to form three-dimensional structures, trimmed using scissors, used to wick fluids (e.g., for microfluidic applications) and disposed of by incineration. Paper-based electronic circuits are thin and lightweight; they should be useful for applications in consumer electronics and packaging, for disposable systems for uses in the military and homeland security, for applications in medical sensing or low-cost portable diagnostics, for paper-based microelectromechanical systems, and for applications involving textiles. [source] Experimental research of pool boiling heat transfer in horizontal narrow spacesHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 5 2004Enshen Long Abstract Much progress has been made in high-performance electronic chips, the miniaturization of electronic circuits and other compact systems recently, which brings about a great demand for developing efficient heat removal techniques to accommodate these high heat fluxes. With this objective in mind, experiments were carried out on five kinds of test elements with distilled water and ethanol as working liquids. The test elements used in these experiments consisted of five parallel discs with diameters varying from 5 mm to 40 mm. The experiments were performed with the discs oriented horizontally and uniform heat fluxes applied at the bottom surfaces. The influence of narrow spacing, space size, working liquid property, and heat flux on boiling heat transfer performance in narrow spaces has been investigated. Experimental results showed that the boiling heat transfer coefficient of a narrow space was 3 to 6 times higher than that of pool boiling when the narrow space size and heat flux combine adequately, but the critical heat flux was lower than that of pool boiling. © 2004 Wiley Periodicals, Inc. Heat Trans Asian Res, 33(5): 307,315, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20017 [source] Algebraic multigrid Laplace solver for the extraction of capacitances of conductors in multi-layer dielectricsINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 5 2007Prasad S. Sumant Abstract This paper describes the development of a robust multigrid, finite element-based, Laplace solver for accurate capacitance extraction of conductors embedded in multi-layer dielectric domains. An algebraic multigrid based on element interpolation is adopted and streamlined for the development of the proposed solver. In particular, a new, node-based agglomeration scheme is proposed to speed up the process of agglomeration. Several attributes of this new method are investigated through the application of the Laplace solver to the calculation of the per-unit-length capacitance of configurations of parallel, uniform conductors embedded in multi-layer dielectric substrates. These two-dimensional configurations are commonly encountered as high-speed interconnect structures for integrated electronic circuits. The proposed method is shown to be particularly robust and accurate for structures with very thin dielectric layers characterized by large variation in their electric permittivities. More specifically, it is demonstrated that for such geometries the proposed node-based agglomeration systematically reduces the problem size and speeds up the iterative solution of the finite element matrix. Copyright © 2007 John Wiley & Sons, Ltd. [source] Four correlates of complex behavioral networks: Differentiation, behavior, connectivity, and compartmentalization: Carving networks at their jointsCOMPLEXITY, Issue 6 2005Mark A. Changizi Abstract Some of the most complex networks are those that (i) have been engineered under selective pressure (either economic or evolutionary), and (ii) are capable of eliciting network-level behaviors. Some examples are nervous systems, ant colonies, electronic circuits and computer software. Here we provide evidence that many such selected, behavioral networks are similar in at least four respects. (1) Differentiation: Nodes of different types are used in a combinatorial fashion to build network structures through local connections, and networks accommodate more structure types via increasing the number of node types in the network (i.e., increasing differentiation), not via increasing the length of structures. (2) Behavior: Structures are themselves combined globally to implement behaviors, and networks accommodate a greater behavioral repertoire via increasing the number of lower-level behavior types (including structures), not via increasing the length of behaviors. (3) Connectivity: In order for structures in behavioral networks to combine with other structures within a fixed behavior length, the network must maintain an invariant network diameter, and this is accomplished via increasing network connectivity in larger networks. (4) Compartmentalization: Finally, for re sons of economical wiring, behavioral networks become increasingly parcellated. Special attention is given to nervous systems and computer software, but data from a variety of other behavioral selected networks are also provided, including ant colonies, electronic circuits, web sites and businesses. A general framework is introduced illuminating why behavioral selected networks share these four correlates. Because the four above features appear to apply to computer software as well as to biological networks, computer software provides a useful framework for comprehending the large-scale function and organization of biological networks. © 2005 Wiley Periodicals, Inc. Complexity 10: 13,40, 2005 [source] | ||||||||||