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In this paper is presented the design and implementation of a ping-pong game on a 7x5 LED matrix based on a microcontroller system. Its implementation involves all processes in typical software development logic, which makes this application to be considered as a pedagogical tool for teaching basic programming content. The design from the perspective of engineering is presented, furthermore is detailed the diagram of the different stages of the system and the structure of the algorithm implemented in the microcontroller. The application allows increase the complexity of programming in so far that increase the conditions and restrictions of operation, generating greater capacity for analysis and alternative solutions. [ABSTRACT FROM AUTHOR]

This paper presents a methodology to find, organize and analyze the information in any field of research, thereby facilitating the acquisition of the available information and the identification of the main authors, the number of publications per year, the main areas of work and the future trends in a proposal topic. It is also, showns an application of the methodology for the topic "Frequency Response Analysis with the transformer in service (FRA on-line)". [ABSTRACT FROM AUTHOR]

Transformers are elements of the utmost importance in the layout of power grids. Their usable lifespan depends on various factors, amongst them, the temperature within their own interior, specially the localized temperature on their insulating material components. Such temperatures are usually approximated through proposed guideline models, however, as stated, these values are approximations and realtime direct measurements would be much more desirable. Due to purely economic reasons, direct measurement is often used for power transformers. However, in the advent of "Smart Grids" distribution system instrumentation will be necessary, as well as the use of cleaner technologies. For research purposes, in this paper, the authors will discuss their experiences in instrumentation with optical fibers in four different distribution transformers submerged in mineral and vegetable oil, for thermal evaluation. The transformers have capacities that range from 15 kVA to 37,5 kVA and operate at voltages of 7620 V/ 240 V. This paper also explains the process of identifying which are the optimal temperature measurement points in the interior of the transformer and leads into the results of temperature rise tests with simulated loads through the use of short circuits and through constant reference fault and actual load at two levels to compare measurements within each of the transformers. [ABSTRACT FROM AUTHOR]

Since the early 1990s, dielectric fluids have been developed from plants. The use of plants has the main advantage of improving the limitations of petroleum oils. Plant fluids are highly biodegradable and have a high flash point; but their high cost and their not-very-wide in-service evaluation (performance), because of its relatively short time of use, have limited their application. This study reviews the state of the art of dielectric oils of plant origin to be used in transformers, including an overview of their evolution from their origin until today. [ABSTRACT FROM AUTHOR]