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Design of Audio Power Amplifiers
Gasnárek, Jiří ; Kratochvíl, Tomáš (referee) ; Šebesta, Jiří (advisor)
The aim of the bachelor's thesis is the description of design and construction audio power amplifiers. This topic is very voluminous and therefore I limited it to basic familiarization with options of bias point placement, connection of power transistors and requested properties of audio power amplifier. It is requested to reach a balanced amplification in transferred frequency band (20 Hz – 20 kHz), to eliminate passage distortion by linearization of passages, to stabilize the amplifier by negative feedback and minimize the signal distortion in limitation by suitable concept of the DC source. Following part contains a suggestion of end transistor properties based on requested output and impendance, their choice (2SC5200, 2SA1943) and calculation of expected heat lost of the amplifier. From known transfer temperatures is set a request on an end transistor cooler. The final part deals with a sketch of scaling way of amplifiers, assumed value and objective comparison of modules. I discuss there possibility of subjective comparison by listening to the same part of sound recording via both modules.
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Power amplifier and its linearization using local feedbacks
Janic, Lukáš ; Musil, Vladislav (referee) ; Khateb, Fabian (advisor)
The thesis deals with the construction of a linear power amplifier. Theoretical analysis of the final work explains the function of the amplifier blocks, which is necessary to understand the functions of the whole construction. Thesis continues in simulation analysis of separate blocks or whole construction and at the end of the implementation of the complete power amplifier.
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Analog distortion musical signals
Růžička, Matěj ; Kubánek, David (referee) ; Vrba, Kamil (advisor)
In this bachelor thesis I studied the differences in sound of valve amplifiers and solidstate amplifiers, causes of those differences, mathematical modelling the transfer characteristic of valve amplifier and then modeling it with simple diode limiter, which used several types of semiconductor diodes, Properties of those diodes were measured as well. Then I constructed limiters for both polarities of input signal, which had non-linear transfer characteristics similar to the valve amplifier and I evaluated their qualities. Then I measured simple amplifier with bipolar transistor, JFET N-channel transistor and optocoupler, Furthermore, I modified triangle-to-sine converters with bipolar transistor, JFET N-channel transistor, measured and evaluated their transfer characteristics. At the end of this bachelor thesis I described designing a diode-based functional converter and converter made from several bipolar transistors, both of these had similar shape of transfer characteristics and I evaluated their qualities by comparing weighted harmonic distortion of the output signal with output signal of tube amplifier.
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Basic measurement of dynamic properties of bipolar and unipolar transistors
Lang, Radek ; Šotner, Roman (referee) ; Dřínovský, Jiří (advisor)
The aim of this bachelor’s thesis is to describe the dynamic parameters of semiconductor devices. The other aim is to build a measuring workplace, on which is possible to carry out measurement of dynamic properties of bipolar and unipolar transistors. The bachelors’s thesis also solves a design and a production of an universal product, on which measurements are carried out. Individual measurement is automated and individual devices are connected to the product and results are controlled by computer analysis.
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Drivers for power switching transistors GaN MOSFET
Fiala, Zbyněk ; Pazdera, Ivo (referee) ; Vorel, Pavel (advisor)
The thesis describes the procedure during the proposal of the driver circuits for the GaN MOSFET transistors, which are known for their fast switching especially. In the first instance of this thesis the issue of GaN MOSFET transistors is described and also the thesis describes the different types of MOSFET transistors in the way of their electrical and mechanical attributes. The specific type driver circuit is stated in the thesis, which was selected in the semestral thesis. For this circuit the boost converter with an output power 600W and high switching frequency 800kHz was proposed as an attempt measurement circuit. This boost converter was measured after its construction was done. The waveforms captured by the oscilloscope are commented also. In the conclusion the assessment is done about this new technology of power switching transistors.
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Market survey of high power semiconductor devices
Gama, Richard ; Adámek, Martin (referee) ; Boušek, Jaroslav (advisor)
In this thesis I will evaluate few discrete devices and their differences in structure, static and switching characteristics and also some structurall and manufacturing principles. After that I will follow up with their integration into power modules , where I will also aim on construction solutions and trends. These power moduls are today delivered as „stack“ or „system“, where for optimization and highest achievable efficiency of the whole unit the integration of protection, drive and cooloing stage is incorporated. Cooling and drive of some devices will be subject of a separate chapter. Also some of novel materials, which are very promissing, will be introduced. They show improvemnet in electrical and thermal properties. They have potential to replace the currently dominant Silicon in the near future.
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Design of Digital Circuits at Transistor Level
Kešner, Filip ; Šimek, Václav (referee) ; Vašíček, Zdeněk (advisor)
This work aims to design process of integrated circuits on the transistor level, specially using evolutionary algorithm. For this purpose it is necessary to choose reasonable level of abstraction during simulation, which is used for evaluation candidate solutions by fitness function. This simulation has to be fast enough to evaluate thousands of candidate solutions within seconds. This work discusses already used techniques for transistor level circuit design and it chooses useful parts for new design of faster and more reliable automated design process, which would be able to design complex logic circuits. The thesis also discusses implementation of this system and used approach with regard to encountered problems in transistor-level circuit design and optimization by evolution.
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Tube guitar amplifier
Mostecký, Jan ; Balík, Miroslav (referee) ; Kratochvíl, Tomáš (advisor)
This bachelor thesis studies guitar tube amplifiers. The thesis introduces basic concepts behind electrical valve circuits. After that there is a scheme of a modified vacuum tube amplifier designed by the author. The functionality of the design has been verified via computer simulation. Designed amplifier was built afterwards and its functionality was verified via measurements.
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Soldering station
Golian, Dominik ; Baštán, Ondřej (referee) ; Macho, Tomáš (advisor)
The goal of this paper is to create a functional soldering station, which would achieve the quality of commercialy available products. The design itself will not be satisfactory without sufficient knowledge of the field. Thus the introductory chapter focuses on a quick overview of matters concerning soldering The attributes are chosen based on market research. The station is equipped with a microcontroller. This allows implementation of usefull functions of several of the compered soldering stations. The practical part contains the electrical solutions and circuit board design. The program taking care of functionality of the entire product is described next. Control structure regulating the irons temperature was selected based on system identification. The result is a product, which satisfies all the requirements.
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Class D power amplifier 2x 2 kW with switching power supply
Tylich, Ondřej ; Pazdera, Ivo (referee) ; Martiš, Jan (advisor)
The content of this thesis is a complete design of an amplifier working in class D, including a theoretical analysis. The thesis describes the functions of individual amplifier function blocks. The appropriate Class D amplifier topology is selected for the application. The design of the amplifier must correspond to the required power of 2x 2 kW to 4. The necessary calculations are performed to ensure the correct function of the amplifier. For reliability, it is necessary to select suitable terminal transistors. The thesis is a theoretical analysis of power supplies. Subsequently, a source with a suitable topology is designed, which will be designed to power the amplifier in class D. All necessary parameters are calculated, especially the power parts. The thesis deals with the design and complete implementation of the entire amplifier, starting with the design of the PCB and their production, subsequent installation, and recovery. After ensuring the function of all parts of the amplifier, various measurements are performed.
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