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Step down DC/DC converter with high efficiency
Chudý, Andrej ; Cipín, Radoslav (referee) ; Procházka, Petr (advisor)
This bachelor's thesis deals with design and realization of several versions of DC/DC buck converter. The theoretical part of the bachelor's thesis is focused on the general analysis of DC/DC converters with a detailed description of the buck converters. Another part specializes in the analysis of the current state in this field, where the basic differences between the synchronous and diode rectifier are explained, electromagnetic interference and GaN transistors are described. Subsequently, the thesis involves the design and calculations of necessary parameters of the buck converter. Calculations are verified by simulation and subsequent production of the first prototype. The basic measurements are performed on the prototype. Detected deficiencies of the prototype are removed in version 1.0. In order to achieve higher efficiency, innovated version 2.0 and version with GaN transistors are produced. The thesis is finished by comparing created buck converters.
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LED driver with synchronous rectification
Hodáňová, Adéla ; Šotner, Roman (referee) ; Kubíček, Michal (advisor)
The main goal of this diploma thesis is to compare two circuits designed for LED powering with output current of units of Amperes. Both circuits are based on step-down converter topology, one with technology of synchronous rectifying and the other one without it. Calculations and selection of used components with real prototypes were made for both selected circuits. All selected components meet automotive qualification requirements for discrete products. Produced prototypes were compared in terms of functionality, efficiency, EMC and thermal radiation.
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Bicycle Additional Drive With A Combustion Engine
And An Electric Powertrain
Doležal, Lukáš
The objective of this paper is power converter design for bicycle with combustion engine and electric power transmission. Converter is powered by a generator which is connected to the combustion engine shaft. The power converter is controlling by microprocessor and control algorithm is designed to achieve maximum efficiently of combustion motor. In this paper is described design of circuits, printed board, driving algorithm and mechanical arrangement of whole powertrain.
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Controled laboratory voltage suplier
Vít, Tomáš ; Valach, Soběslav (referee) ; Macho, Tomáš (advisor)
The aim of my master’s thesis is the design and implementation of laboratory power supply with output parameters 0-25V and 0-2A and options to manage this resource by elements of the front panel or via a computer control program. Content is the theoretical analysis of the possibility of subsequent theoretical sources suggesting that it verified on the prototype laboratory resources.
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New Conceptions of Power Pulse Converters Using Extremely Fast Switching Semiconductors Based on SiC
Kuzdas, Jan ; Chlebiš,, Petr (referee) ; Drábek,, Pavel (referee) ; Vorel, Pavel (advisor)
This work deals with high power pulse converters (tens of kW) using new semiconductor devices of silicon carbide (SiC). Firstly the current state of the issue is analyzed. A research in a specific area of high power buck converters with pulse transformer follows. There was a strong emphasis on minimizing size and weight. The design process was focused also on reliability and robustness. To achieve the defined objectives, it was necessary to use the latest available switching transistors and diodes, and an unusually high switching frequency (100 kHz at a power of about 16 kW). Due to the high switching frequency, we achieved small size of pulse transformers and output chokes. An optimization of high-frequency pulse transformer with demand on minimum volume and weight of core and windings represents a separate theoretical part of the thesis. There have been proposed several analytical solutions of optimization problems, the results of which could overlap with the implementation in practice of switching power supplies. The combination of high switching frequency, fast semiconductors and the high power brings various parasitic effects to the power circuit. In the thesis, these parasitic effects are analyzed. Solutions which minimize or completely remove those effects were theoretically designed and successfully implemented, tested and finalized in experimental part of the work. Detailed description of the implementation of functional sample and series of validation measurements are included in the final part.
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Traction Li-ion accumulator 28V/40Ah with internal protecting and control circuits
Kovář, Robert ; Pazdera, Ivo (referee) ; Vorel, Pavel (advisor)
This work is a design and construction solution for an inteligent charger of Li-Ion battery system.The system consists of an accumulator, built out of individual cells (serial-parallel sequence), protective and monitoring circuits and charger with control circuits. These control circuits of this charger collaborate with monitoring circuits. The base of this charger is a switching source (singlemode buck converter with transformer).The charger allows to supply relatively high power while sustaining small dimensions.(20A with 28V that´s 560W) Use of DC/DC converter is a base of charger and also delivers other benefits, such as high efficiency and easy control of output current.
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Control of power LED, using ATtiny
Sedláček, Michal ; Pust, Radim (referee) ; Zeman, Václav (advisor)
The bachelor thesis deals with designing DC/DC steep-down converter, intended to supply power LED from a lithium-ion batteries. Work on the preface introduces the reader to the functions and the requirements for the proposed facility. Steep-down converter is controlled by a microcontroller suitably selected from ATtiny family. In this work are gradually dismantled partial circuit solutions, from which is then compiled a complete circuit. Is analyzed in detail the proposal steep-down power circuit converter. Work also includes the program for microcontroller and PCB design for the final circuit solution. In conclusion, this work is carried out measurements on the sample the proposed facility.
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Precise adjustable power suplly
Pawlas, Andrzej ; Magát, Martin (referee) ; Kadlec, Jaroslav (advisor)
This bachelor´s thesis deals with the proposing precise switching power supply. This switching power supply works with a maximum of 99 % duty cycle. Input voltage is 12 V and output can be set in the range of 1.2 V - 11.9 V. Current can be a source of burden 0 A - 20 A. The entire power supply is controlled by microcontroller. While addressing the proposal switching power supply have been developed five prototypes. Last prototype works well, but the output appeared significant interference.
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