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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Třífázový měnič pro synchronní servomotory / Three-phase converter for synchronous servomotors

Perout, Miroslav January 2020 (has links)
This diploma thesis is dealing with the design of a DC / AC converter for the control of PMSM motors. In the first step, the type of motor and the possibilities of sensing the position of the rotor are described. Subsequently, the power section is designed and the losses, heating, and approximate efficiency of the inverter are calculated. In the following step, the processor is selected and individual communication and protection circuits are designed. At the same time, control algorithms are analyzed. The last part is describing the implementation of the PCB and the inverter as a whole.
82

Bezkontaktní měření teploty pomocí luminiscenčních materiálů / Noncontact temperature measurements using luminescent materials

Jedlička, Jindřich January 2020 (has links)
This diploma thesis deals with noncontact temperature measurement using luminescent materials. In the theoretical part of the thesis, luminescent materials were selected on the basis of a literature review with respect to sensitivity and operating temperature range. In the experimental part of the thesis, photoluminescence of CdSe/ZnS and GaAs quantum dots for various temperatures was measured and the relative change of luminescence parameters such as emission peak position, intensity, intensity ratio of two emission peaks, and lifetime of luminescence were determined from the measurements in agreement with expectations according to the literature. Achieving high spatial resolution would be made possible by measuring cathodoluminescence, where the luminescence spectra are obtained with an order of magnitude higher spatial resolution. These measurements and the influence of electron beam on the luminescence quality of selected materials will be subject of further experimental study.
83

Aplikace optických vláknových senzorů / Applications of optical fibre sensors

Ráboňová, Jana January 2021 (has links)
This master's thesis deals with the measurement of soil temperature. In the theoretical part, optical fiber systems were explained, with a focus on DSTS systems and their use. In the practical part, a functional system was created to measure the soil temperature at depths of 0.1-1~m using the Arduino platform. Furthermore, the temperature measurement was demonstrated on the test polygon using the optical fiber of the FTB 2505 instrument in laboratories.
84

Vliv teplotních závislostí luminiscence solárních článků / Influence of temperature dependence of luminescence solar cells

Koutný, Michal January 2010 (has links)
This work deals with determination defects in solar cells using non-destructive methods. Defects are determinating by electroluminescence method and microplasma method in temperature influence. Temperature will be changed by Peltier cells. By using this various temperatures during the testing we can receive more objective results thanks to simulated operation conditions.
85

Referenční zdroje napětí a proudu / Voltage and current reference sources

Skalický, Pavel January 2011 (has links)
The topic of the master´s thesis are voltage and current reference sources. There is detailed description of current and voltage references, which are basic building blocks of many analog circuits, in the theoretical part. Next part of the master´s thesis is the design of a voltage reference source, the design of a voltage reference generating two voltages and a current reference source. The correct function of all circuits have been verified using simulations, especially dependence of the output voltage or current on supply voltage or dependence of the output voltage or current when the ambient temperature is changed.
86

Teplotní analýza asynchronního stroje pomocí programu Ansys Workbench / Thermal analysis of induction machines using Ansys Workbench

Kučera, Petr January 2012 (has links)
The aim of the master thesis is introduction with software Ansys Workbench and calculate the thermal field arroud the induction machine. After introduction with the software was bulit model of induction machine and there were simulated various thermal calculations at operating conditions. They were measured on a real induction machine in laboratories.
87

Teplotní analýza elektrického stroje / Thermal analysis of electric machine

Ječmínek, Tomáš January 2013 (has links)
This masters thesis is focuse for measuring devices of temperature and their usability and accuraci in the event of asynchronous engine in operation. The values from meusuring of engine are used for preparing optimalization of construction. The right proposal of construction is check in numerical program and the results are validation.
88

Dynamická viskozita elektroizolačních kapalin / Dynamic viscosity of electroinsulating liquids

Míka, Petr January 2013 (has links)
This work deals with persepective environmentally friendly electroinsulating liquids. Important properties of currently used electroinsulating liquids are listed. Physical nature of viscosity of liquids and its temperature dependance are described and methods of its measuring are listed. Also temperature dependance of density is described from physical point of view. Measurement of density and of temperature dependance of viscosity of chosen vegetable and mineral oils was performed. On the basis of this measurement was calulated the activation energy of these samples. Two methods of dynamic viscosity measurement were used for some samples.
89

Měření hmotnosti pomocí tenzometrů z elektronických vah / Weight Measurement with Bathroom Scale Strain Gauges

Šenfluk, Petr January 2014 (has links)
The aim of the thesis is weigh measurement using strain gauges from cheap digital scales. Work describes problems connected with using strain gauges as temperature compensation and requirements for accurate voltage reference and summarize function and wiring of chaep digital scales using four strain gauges. Result of work is design of an electrical circuit for weigh measurement using four strain gauges from analyzed scale.
90

Návrh a simulace čipu mikrobolometru v MEMS technologii / Design and Simulation of Micro-Bolometer in MEMS Technology

Svatoš, Vojtěch January 2014 (has links)
Tato diplomová práce zkoumá problematiku detektoru infračerveného záření nazývaného bolometr. Cílem je pokrok v detekci infračerveného záření použitím odlišné absorpční vrstvy modifikovanou karbonovými nanotrubicemi. V teoretické části jsou uvedeny základní fyzikální pojmy z problematiky teplotního managmentu a základních fyzikálních vztahů bolometru. Design bolometru je představen a popsán. Teplotně mechanické simulace předvídají chování bolometru při detekci infračerveného záření. PSpice model je vytvořen a kombinuje termální a elektrické vlastnosti čipu bolometru. Dále je uveden proces výroby bolometru, které je detailně popsán.

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