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SELV power sources
Friedl, Martin ; Murina, Milan (referee) ; Sedláček, Jiří (advisor)
The aim of this diploma paper is to examine the required characteristics of power sources SELV which are used for electric devices of category III. The first part of this diploma paper deals with general knowledge considering power sources. With the focus on switching power sources SELV, their overcurrent, thermal-overload and overvoltage protection and possible solutions of power sources SELV from the aspect of the required isolating safety. The second part of this work deals with the specific design of the power source SELV 230VAC/24VDC with the power output to 70W, with its implementation and with the measuring of its parameters.
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Current-Input Current-Output Active Circuit Elements and their Applications
Vávra, Jiří ; Sedláček, Jiří (referee) ; Maschke, Jan (referee) ; Biolek, Dalibor (advisor)
The thesis deals with definitions of new current- or mixed-mode circuit elements and their implementations and applications. Based on the analysis of the state-of-the-art, novel application circuits employing the above circuit elements are designed. For the purpose of the experimental verification, the active elements are implemented via commercial integrated circuits, and their applications are simulated via PSpice. The application circuits are focused on frequency filters, rectifiers, oscillators, and current-copy circuits. Selected applications are analyzed with respect on real influences, and measurements on circuit prototypes are also performed.
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Adaptive frequency filter
Kříž, Petr ; Hájek, Karel (referee) ; Sedláček, Jiří (advisor)
The aim of this work is to design a filter of the type low–pass of order 5th with Butterworth’s approximation in the range of over-tuning 10 – 100 kHz and if it will be possible so! achieve even higher marginal frequencies. To compare two typical representatives of the frequency filters cascading and non-cascading synthesis from the viewpoint the accuracy of an! approximation function, sensitivity to the tolerance values of components, number of the components (mainly OZ) and viability, especially the possibility of electronic over-tuning in selected frequency range. On the basis of these conditions will be chosen one design, which will be realized later. Further it will be necessary to consider the possibilities of electronic over-tuning and to choose for this over-tuning suitable component, to design user management changes of marginal frequency fm by the help of keyboard + LCD and control application on the PC. For this hardware will be programmed appropriate control software. At the end of this work will be constructed appropriate device, which fullfils requirements written above and will be subjected to the laboratory measurements that verify function of this device. The constructional details of the filter are presented in the enclosure at the end of this work. At the CD are available all materials, which were created during the master’s thesis or which are necessarily concerned.
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Organic semiconductors and their applications
Galbička, Tomáš ; Sedláček, Jiří (referee) ; Hubálek, Jaromír (advisor)
Bachelor’s thesis is deals with a problem of organic semiconductors, where are describe fundamental principles of charge transport and explanation of basic organic structures. There is described basic operation and layering of simple organic parts especially organic diode. There are practical tests of electrical properties of two different polymer diodes PLEDs. Where in this experimental part are present characteristics of these parts and them comparison at variant ilumination and mutually measuring.
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Family house
Sedláček, Jiří ; Šagát, Erik (referee) ; Matějka, Libor (advisor)
Bachelor thesis solves a design of a house in the village Čechočovice district Třebíč. The house is located on plot No. 1101/4 in the cadastral Čechočovice. The land is gently sloping and its area is 1071,03 m2. Ground-plan of the building is shape L, the exterior dimensions are 19,25 m x 13,00 m. House has two floors with a partial basement. Roofing is solved over ground floor a single-layered flat roof, walkable flat roof above the first floor double-layer flat. House is designed as a classical brick technology of heat-insulating ceramic fittings Heluz Family 2v1 with polystyrene foam inside the cavities and is based on concrete strips. The building is designed for four-to five member family.
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ARC filter for frequency analyser
Janečka, Martin ; Murina, Milan (referee) ; Sedláček, Jiří (advisor)
The aim of this work is to propose and realization an active frequency filter with a 4th grade bandpass for making it possible to electronically tune the resonant frequency in range of 10Hz to 100kHz and adjust bandwidth. The thesis discussed two possibilities of filter connections using cascade synthesis. To choose a better option a filter simulations were made in Pspice. Based on the simulations, the number of components and the possibility of electronic tuning a better option is selected. This circuit is implemented, measured and then compared with simulations.
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SYNCHRENOUS RECTIFIERS IN SWITCHMODE POWER SUPLIES
Špatenka, Jan ; Sedláček, Jiří (referee) ; Murina, Milan (advisor)
The aim of this project is synchronous rectifier in switched-mode power supply. The project deal with possibility, how increase in efficiency in SMPS. For increases in efficiency are very important analysis particular power losses. One from possibility how increase in efficiency is replace Schottky diode in output rectifier by synchronous rectifier, with is consists of a power MOSFET. The second part of this work is focused on practical realization SMPS with synchronous rectifier and with output power . The main task was reach high efficiency. On the end of there is comparing of rectifiers and electric measuring has been making.
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The universal timer
Kobza, David ; Murina, Milan (referee) ; Sedláček, Jiří (advisor)
Overview of basics functions characteristics and requirements of timing device. Design of basic controlling unit and designating part. Description about basic parts and characteristic of their activities. Schematics presentations for realisation. Detailed instructions for handling device. Firmware of device in LSA. Evaluation goals, overview of informations sources and list of using literature sources.
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Usage of Financial Analyses for Improving Business Performance
Sedláček, Jiří ; Oulehla, Jiří (referee) ; Luňáček, Jiří (advisor)
This bachelor thesis is focused on evaluating and improving the financial performance of Ferona, Plc. using the method of financial analysis. The first part of the thesis theoretically deals with individual concepts of financial analysis. In the second part, the theoretically described methods are applied to the company financial situation and the results are compared with the industry average and the main competitor results. In the last part, there are suggestions for possible improvements of the current financial situation of the company.
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