385 research outputs found

    Island Operations of Electric Generators Connected to One Substation

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    While increasing integration of renewable energy sources (RES), which are unregulated and difficult to predict, a large system of nuclear power plants must provide balancing peaks in the production of renewable energy. It is also important to simulate the rapid changes in the power of individual large Nuclear Power Plant (NPP) units, and for these regimes to train operators of nuclear units. Therefore the paper is aimed to island operations of more parallel electricsynchronous generators connected to one substation of a power grid

    Using microcomputers for lighting appliance control using a DALI bus

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    Article concerns the DALI bus theoretical and practical aspects. The DALI bus is a modern technology developed especially for illumination systems control. Authors are outlining communication basic principles related to the physical layer and going up to more complex data transactions among particular devices. The article main topic is aimed at two device models development based on microcontroller and exploiting that technology. The first of those two devices is a DALI slave unit enabling the light source or multi switch with light indication components control via DALI bus. The second device measures the ambient illumination intensity and it also detects errors in the load.Ministry of Education, Youth and Sports of the Czech Republic within the National Sustainability Programme [LO1303 (MSMT-7778/2014)]; European Regional Development Fund under the project CEBIA-Tech [CZ.1.05/2.1.00/03.0089

    The family house control system based on Raspberry Pi

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    The article deals with the design and implementation of a smart household based on simple wireless modules, which are monitoring (collecting data) and controlling smart household supporting devices. The central unit processes measured parameters, and in relation to resulting values, a pre-set action is performed. Those actions variety can be configured by user via the user interface so that a set of smart rules for reaction on by household devices generated stimuli or problems can be created. That all together composes a control system based on Raspberry Pi, which manages indoor and outdoor temperature measurement, the lighting control, RF transmitter, jalousie, motion sensor control etc. There is a GUI for a PC and for a mobile phone as a part of that system. © The Authors, published by EDP Sciences, 2017

    An alternative to the band saw wheel wear measurement

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    There exist various methods how to measure the band saw wheel wear. Our article describes an alternative to the existing ones. To give an idea about that problem, we first describe the band saw components in general, and we are also summing up nowadays measurement methods. In contrast to them, we present our alternative solution based on laser sensors. The article contains the design realization example and the functional description of related application software. The testing measurement data illustrates our solution achievement. Our design benefits highlights are formulated as well. © 2018, World Scientific and Engineering Academy and Society. All rights reserved

    System for automatic inspection of bandsaw blades

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    The article deals with a new inspection method for the bandsaw blade eligibility checking. For better understanding, the individual bandsaw blade areas are described together with relevant parameters overview. The method design description follows. The current method drawback are discussed, and there are stressed the advantages of our innovative automatic inspection method. We present arrangement of our design in individual blocks together with the application software functions. The article also presents both the design model and the realised prototype measurement results. The constructed device based on our design minimizes the human error influence. © 2019, World Scientific and Engineering Academy and Society. All rights reserved

    Measurement of complex permittivity in free space

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    The paper describes the measurement of complex permittivity in free space. It is an advanced non-contact method which is used to find the electromagnetic properties of materials. In this case it involves the materials which are used in aviation technology, especially for hardening the avionics against electromagnetic interference. A specialized laboratory workplace equipped with the vector network analyzer ZVA 67 from Rohde and Schwarz was built for the measurement. Initial measurements were performed at high frequencies from 220 to 325 GHz on a Teflon sample because of the ease of verifying the results. The high frequency range was achieved by using ZVA-Z325 converters from the same company and the respective antenna systems. This measuring system was used for determining the transmission coefficients. The complex permittivity which characterizes the electromagnetic properties of the material for the above frequency range was found by iterative method programmed in Matlab environment. © 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license

    Raman spectroscopic study of counterfeit electronic components

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    The paper deals with the potential of Raman spectroscopy as an analytical method for the authenticity assessment of electronic components. Electronic components are an integral part of the devices that people use in their daily activities. Incidence of counterfeit electronic components is an increasingly common phenomenon in our modern world that may compromise reliability, functionality and other related purposes of the devices. As the Raman spectroscopy provides detailed information on the material used, the focus of the Raman spectroscopic study of selected original components was given especially on materials of polymer-based and ceramic-based packages and markings. Knowledge of this information can help to distinguish between genuine and counterfeit component. The non-original component was revealed using other methods used in our workplace. Raman spectroscopy also confirmed the differences in materials of counterfeits compared to the original. © 2018, World Scientific and Engineering Academy and Society. All rights reserved

    The counterfeit components V-I characteristics difference study

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    The electronic component V-I characteristics express a relationship between the current flowing via a chosen couple of pins, and the voltage applied on those pins. That voltage varies between two safe, for the component health limits, during the V-I characteristic recording. The applied voltage variation follows a certain function like sinus or ramp. The V-I characteristics of an individual component type can differ according to production technology, according to a particular manufacturer, or according to measurement conditions itself. Those so called natural differences can be registered by the study of statistically significant component population with known origin and history, and they can be subsumed in the comparison master pin print. That comparison master pin print is subsequently used as a criterion for discovering differences caused by improper treatment, failure or by the counterfeiting process. The article illustrates a counterfeit detector application for comparative V-I characteristics analysis aimed at a relevant knowledge base development for particular production technologies and component types

    Design and implementation of lenses for shaping the beam of millimeter waves in free space

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    This paper deals with the beam forming of the electromagnetic waves with a wavelength in the order of millimeters. The goal is to design, implement and verify the dielectric lens of a suitable material for shaping the beam of millimeter waves to the plane wave and refine and analyze signal frequency range from 220 GHz to 325 GHz. For this purpose a specialized measuring workplace is used. It is equipped with the vector network analyzer ZVA67 by Rohde and Schwarz. It also includes millimeter wave converter for achieving the frequency range up to 325 GHz. The measurement is performed in free space with respective circular antennas. Three measurement methods are used to verify the proper function of developed lenses. The aim is to get the system of dielectric lenses in the millimeter band, which would replace the complicated system of mirrors. In the implementation of the system it is necessary to pay attention to the accuracy of manufacture and the quality of the chosen material

    Remote controlled gate controller using a GSM network and Arduino platform

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    Most remote controllers for entrance gates operate on free frequencies 433 or 868 MHz. However, this technology limits the user comfort, as it is usually not common that bi-directional communication is established. A higher comfort of controlling the entrance gates can be achieved by employing the GSM network for transmission of commands and messages between the gate controller and the user. In this case, only a conventional GSM cellular phone is needed to control the gate. A description of such a controller based on the GSM module and Arduino controller is provided in this paper.Ministry of Education, Youth and Sports of the Czech Republic within The National Sustainability Programme Project [LO1303 (MSMT-7778/2014)]; European Regional Development Fund under the project CEBIA-Tech [CZ.1.05/2.1.00/03.0089
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