The paper approaches the process of testing for analogue quality transmission over plastic optical fiber (POF) system. For this purpose, we have designed a transmitting/ receiving interface built around TO082 (a wide bandwidth dual JFET input operational amplifier, with low input current and voltage noise), with programmable amplification controlled by microcontroller. A signal generator injects standard audio signal and the microcontroller evaluates the attenuation caused by the POF in the case of new, and five-year use of optical fiber. The measurements prove the "aging" of the fibers, with deterioration of the attenuation parameter.
This present paper approaches the field of methods of measurement of electrical parameters of solid polymer materials, using new techniques to ensure high level accuracy as well as controlling and minimizing errors. To achieve this goal we designed an original measuring stand with a single microwave oscillator and two measuring arms. Using this measurement method, it is possible to control and eliminate the amplitude variations, depending on the frequency variations of the Gunn diode, so that for any microwave frequency range 8.5 - 9.5 GHZ, the amplitude of the input signal in the measuring system is kept constant. The measurement installation is intended for microwave absorption measurements for electrically insulating solid polymeric substances.
An automatic tester was developed for optical fiber transmission system over its performance parameters during optical fiber lifetime. For this purpose, we have designed a signal conditioning module for fiber optic waveguides. For sending and receiving data over optical fiber we have used a typical TTL adapter built with MC10H116 (a triple differential amplifier designed for use in sensing differential signals over long lines). A microcontroller- based system is used to measure the correspondence between a sending and receiving of a string sequence over a glass optical fiber probes. The measurements prove the “aging” of the fibers, with deterioration of the speed parameter.
The paper presents a smart system for control of chromatic distribution of white light produced by LED sources in order
to satisfy simultaneously physiological comfort and color rendering requests. In region of interest (ROI) lighted by an
ensemble of RGB and white LED’s, a system of appropriate light sensors (from UV to IR radiation) take the chromatic
an intensity information and send them to a microcontroller based device. Following the actual state of illumination end
the desired one, the microcontroller will command the LED drivers adequately to obtain the optimum situation.
KEYWORDS: Light sources and illumination, Safety, LED lighting, Buildings, Light emitting diodes, General lighting, Lamps, Energy efficiency, Eye, Reflectors
The paper presents the work and results obtained by our team in studying the possibilities of improving the artificial lighting in industrial environments. Lighting solutions in industrial environments are mixed, a general lighting system aiming to establish enough lighting level for production halls together with a local lighting system in order to ensure a suitable lighting level for operations realized and appropriate comfort for human perception of light. These two main goals are accompanied by other objectives like energy efficiency, easy maintenance, a good ratio lifetime/price [5]. We monitored a trader of electrical wiring for automotive with continuous activity (24 hours) and based on measured level of lighting we proposed solutions aiming the completion of before mentioned targets.
This paper is a part of our research dedicated to high power LED lamps designing. The boost-up selected technology wants to meet driver producers’ tendency in the frame of efficiency and disturbances constrains. In our work we used modeling and simulation tools for implementing scenarios of the driver work when some controlling functions are executed (output voltage/ current versus input voltage and fixed switching frequency, input and output electric power transfer versus switching frequency, transient inductor voltage analysis, and transient out capacitor analysis). Some electrical and thermal stress conditions are also analyzed. Based on these aspects, a high reliable power LED driver has been designed.
The paper is focused on designing a smart LED power supply, with adjustable working point in accordance with local conditions, LED photometric characteristics. We have develop a flyback driver controlled by a signal which is a combination of the sensed LED forward current, and a PWM working regime. This method is used in order to increase the LED lighting efficiency at the same thermal regime. At the end of the implementation we have tested major issues related to the correct work of the LED, energetic and luminous efficiency, and the way of sensor integration into the smart system.
This paper approaches the design of a smart lighting system for efficient lighting of pedestrian crosswalks on streets, using power LEDs. Starting with existing solid-state lighting - SSL (power LEDs with individual directivity diagram, lighting efficiency and color rendering index - CRI) in the paper we propose a design technique and methodology in order to find the distribution geometry of light sources (sources number, spatial coordinates, fixing angles) that simultaneously satisfy the lighting regulation requests and energetic efficiency. The major achievements are the simulations of using of a great number of LED lighting sources and of spatial lighting configurations in order to obtain of a uniform lighting of the area of interest (fig.1) and in conformity with actual standards in a specified scenario. The direct consequence of these simulations is the using of an intelligent management system of LED lighting sources that will allow the optimization of light flux in real traffic conditions of cars and pedestrians. This means the monitoring of traffic level and surrounding conditions (temperature, humidity, natural lighting etc.) in order to efficient use the existing resources.
The paper approaches the lighting optimization of industrial production areas, using the remote microcontroller command of lighting sources. The lighting of industrial production areas is stated by the Design and execution of building artificial lighting standard - NP 061- 02 that specifies the lighting level of working and of the neighbor area, in order to assure work comfortable condition and to avoid work accidents. As consequence, in production companies, particularly in those were the activity is in continuous flow, it is a great concern on an appropriate lighting but also on minimal energy consumption. The main achievement is the lighting optimization intending a uniform light flux over the working surface, with minimal energy consumption through the individual or group command of lighting sources, depending on the measurement of lighting level.
The rapidly developing field of data mining and knowledge discovery in data is a blending of artificial intelligence,
statistics, and human–computer interaction. The task of data mining is to determine the data pattern from a given set of data. This paper shows the usage of an algorithm of data mining based on clustering, in order to find different data categories in a wind farm data. Once these data categories have been identified, the most suitable prediction technique can be determined. The authors study several Artificial Neural Networks (ANN) topologies in order to establish the most accurate one for every found data category. The experiments were done using real data acquired from a monitoring sensor system.
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