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Energetic problems of induction electroheat equipments
Milka, Jiří ; Paar, Martin (referee) ; Lázničková, Ilona (advisor)
Induction heating is mostly used for melting metal materials in metallurgy. The principle of induction heating comes from electromagnetic induction which generates eddy currents heating the charge in electrically conducting material. The first part of the bachelor thesis is devoted to the principle of induction heating. Further, there are possibilities of applying the induction heating in electro heat devices mentioned. As the paper is focused on energy problems appearing when getting connected to the grid, the second part of the paper contains explanation – both theoretical and on examples - of compensation and symmetrization of induction electro heat devices.
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Band Gap - accurate voltage reference
Bubla, Jiří ; Petržela, Jiří (referee) ; Kolka, Zdeněk (advisor)
This diploma thesis is specialized on a design of a high accuracy voltage reference Bandgap. A very low temperature coefficient and output voltage approx. 1,205V are the main features of this circuit. The paper contains a derivation of the Bandgap principle, examples of realizations of the circuits and methods of compensation temperature dependence and manufacture process, design of Brokaw and Gilbert reference, design of a testchip and measurement results.
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Machine Tool Spindle Units: Active Tool Deflection Compensation
Zarboch, Jaromír ; Vetiška, Jan (referee) ; Březina, Tomáš (advisor)
Cutting forces during milling process cause tool deflection. There are several methods for compensation of this deflection. This paper is focused on the active method of tool deflection compensation which angles adaptronic spindle by piezoactuators to compensate the tool deflection. For this method the simulation model was built in programe Matlab / Simulink. The effectiveness of this model was validated by search simulations.
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The Optical Fibre Dispersion Effects on Multiplex Transmission Systems
Kyselák, Martin ; Filka, Miloslav (advisor)
This doctoral thesis deals with present trend to turn up the bit rate of the optical fibres making use of wavelenght multiplex systems. There are new theoretical and practical problems caused by the new technologies. Except the known modal dispersion there exist problems caused by chromatical and polarization mode dispersion. In the opening of the thesis the known effects, which influence the payload signal, are introduced. The polarization mode dispersion has the main attention. Within the scope of this thesis there has been programmed the statistical calculator which can analyses the measured values of differential group delay by Monte Carlo calculation. Next meaningful output is the designating application of the optical routes. It is possible to mathematicaly unambiguously define the polarization mode dispersion by Jones, Stokes and Poynting vectors. This complicated calculations are mechanized and in the simulation application make possible to simulate the signification of the PMD influence at different input parameters. The thesis includes the study of the PMD modulation format impact with the results of simulations and confrontation with other scientists results. The significant output are the final practical results examinations, which can be implemented thanks to the possibility of using the FTB-5500B measuring device.
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Power engineering issues of electrothermal devices
Popelář, Vojtěch ; Radil, Lukáš (referee) ; Lázničková, Ilona (advisor)
Electric furnaces are one of the largest consumers of elektricity. They have a large negative impact on the electricity grid. Therefore, it is necessary to optimize their work process. The thesis deals with energetic problems of high power electric furnaces. The first part provides a theoretical overview of types of electric furnaces, their types, properties and possibility of connecting to the electricity grid. For this work were selected resistance furnaces, induction furnaces and arc furnaces. The second part analyzes the problem of correcting power factor cos and the problem of unbalanced electricity consumption. For both these problems are given the possibilities for removing or reducing the negative characteristics of these phenomena. At the end of this section is an example of compensating equipment design and symmetrizating device design for selected types of electric furnaces.
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Passive shunt filtration and compensation
Urant, Tomáš ; Novotný, Jan (referee) ; Drápela, Jiří (advisor)
The aim of this work is to acquaint the reader with the theoretical and practical design filtration-compensation device. The theoretical part describes the problems of reactive power compensation and harmonic filtering components. There are described various methods and implementation of compensation and filtration-compensation devices. In the practical part is the theoretical basis used for the realization of a laboratory model of filtration-compensation device for precisely specified load with precisely specified requirements. In laboratory model can be seen meaning of filtering harmonics by using of simple hand switching individual filters.
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Dispersion effects in high-speed optical networks
Filip, Tomáš ; Šporik, Jan (referee) ; Tejkal, Vladimír (advisor)
This bachelor’s thesis is focusing on optical transmission principal, its transfer mediums and furthermore also with focusing on its advantages and disadvantages. First half of this thesis focuses on adverse influences, which affect signal transmission in optical networks, on dispersion influences, especially on Polarization Mode Dispersion (PMD). Second half of this thesis deals with measuring of properties of optical fibers, largely chromatic and polarization mode dispersion, used methods and its principals. Furthermore, there are mentioned current compensation possibilities. The seventh chapter deals with optical route simulation in OptiSystem and testing chosen compensation methods for bit rate 40Gb/s. In the last chapter there are elaborated results of real optical route measurements for Masaryk University.
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Impact of conventional compensation to the volumetric accuracy of the machine tool
Žák, Zdeněk ; Vetiška, Jan (referee) ; Holub, Michal (advisor)
This thesis solves the impact of conventional compensation to the volumetric accuracy of the CNC machine. It is therefore a practical research work, where are in the theoretical introduction mentioned requirements for machine tools, the types of errors that can occur on three-axis kinematics, compensation for the control system Siemens Sinumerik 840D sl and devices by means of which are these compensation under the work formed and subsequently verified. In this work can be seen the measured values and graphs from each measurements, a detailed analysis of the results and drawing conclusions from these results.
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Erors and Uncertainties in Temperature Measurement
Jirmásek, Jakub ; Vojáček, Zdeněk (referee) ; Vdoleček, František (advisor)
Bachelor thesis is focused on sources of temperature measurement uncertainties and their expressing. There is a basic description of the temperature as a physical quantity and its scale. The study describes some kinds of thermometers, focusing primarily on electric thermometers which have a dominant position in the field of automation and regulation. Further the importance of measurement uncertainty is described and its expressing. More space is devoted to the importance of different sources of uncertainty and possible compensation. Finally there is an example of determining the measurement uncertainty.
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Thermoelectric device for measuring temperature
Melničuk, Petr ; Kandus, Bohumil (referee) ; Podaný, Kamil (advisor)
This thesis presents the application of thermocouples for measuring temperature. Thermocouples are a kind of contact thermometers, thus requiring direct contact with measured substance. Their advantages include great flexibility due to wide choice of material combinations, which makes it possible to achieve various operating temperature ranges, anywhere from -200 to 1800 . Improper choice of thermocouple may result in added systematic error or even render it unusable. Based on literary research, individual configurations, methods of measuring liquids, gases, and solids and their practical applications were presented. Lastly, an experiment was conducted, where three different type 'K' thermocouples were compared and deviations between their measurements were assessed.
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