National Repository of Grey Literature 78 records found  beginprevious59 - 68next  jump to record: Search took 0.02 seconds. 
Graphene Field-Effect Transistor as a Probe of Doping by Adsorbed Oxygen Molecules
Blechta, Václav ; Mergl, Martin ; Drogowska, Karolina ; Kučera, Lukáš ; Valeš, Václav ; Červenka, Jiří ; Kalbáč, Martin
Graphene has high potential in chemical sensing, thus understanding adsorption and charge transfer between graphene and adsorbed molecules is essential. We show that graphene field-effect transistor exhibits a moderate sensoric response towards oxygen at temperature of 150 °C. Field-effect transistors serve as a tool to probe electronic properties of graphene. We demonstrate that adsorption of oxygen molecules onto graphene leads to an upshift of Dirac point and light changes in mobility of charge carriers.
Specifications of swithced DC/DC convertors used for automotive applications. Parameters of suitable MOSFETs, option fo partials damping of their switching operation
Langer, Lukáš ; Froehling, Kenneth (referee) ; Walek, Agata (advisor)
Tématem bakalářské práce je úvod k využití nových prostředků pro osvětlení automobilů, zejména pak osvětlení pomocí LED. Tato práce bude zaměřena právě na systém LED osvětlení a jejich zapojení a spínacích obvodů. Dále bude práce věnovaná LED budičům pomocí MOSFETů, jejich parametrům a vlivům na jejich obvody. V práci bude také popis samotného měření daných obvodů s rozborem měření i jeho výsledků. Práce necílí na technické detaily, ale těžiště je ve zvládnutí jazyka při obecnějším popisu principů a postupu měření.
High effective switched power supply
Rástočný, Martin ; Kledrowetz, Vilém (referee) ; Pavlík, Michal (advisor)
This bachelor’s thesis analyses theoretical basis of switched mode power supplies. Selections of right topology for implementation, design of power and control circuits are discussed. The thesis also contains a brief summary of switched mode power supplies. Subsequently it focuses on calculations and selection of appropriate power components. A result of the thesis lies in development and practical design of switched mode power supply and its optimization for high effectivity of conversion. To achieve these theoretical calculations of parameters for chosen topology were made.
Basic measurement of dynamic properties of bipolar transistors
Repčík, Juraj ; Šteffan, Pavel (referee) ; Dřínovský, Jiří (advisor)
The aim of this bachelor thesis is to analyze theoretical basis of measurement bipolar transistors. First, this project focuses on the static parameters of a bipolar transistor, setting DC voltages and currents in an electric circuit (Q-point, operating point). Second it deals with measurement of selected dynamic properties of amplifier with bipolar transistor. Theoretical knowledge is presented on the practical circuit by a laboratory measurement of the selected properties. The measurement is automated using a computer with LabVIEW software. User programs are developed for measuring the V-A characteristics of a bipolar transistor and for measuring selected dynamic properties of the amplifier. The thesis points out a convenient approach in development of new software for automated measurement using graphical programming in LabVIEW.
Regulated power supply 50V/5A
Herman, Tomáš ; Vorel, Pavel (referee) ; Huták, Petr (advisor)
Bachelor´s thesis deals with the adjustable DC voltage source. The first part deals about the typical involvement of resources and consequently the properties of individual components resources. The second part is the actual design of control circuits, selection of components, wiring and PCB design.
Drivers for power SiC MOSFET transistors
Vitek, Vojtech ; Vorel, Pavel (referee) ; Procházka, Petr (advisor)
The bachelor thesis describes gate driving principles of power MOSFET transistors made of silicon carbide material. The autor's aim is describing a different types of gate drivers and basic rules during process of designing gate drivers. In the theoretical part, the author will mount printed circuit board of gate driver designed on UVEE FEKT VUT Brno and verify functionality.
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.
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.
Design of switch-mode audio power amplifier
Macek, Libor ; Petržela, Jiří (referee) ; Brančík, Lubomír (advisor)
This paper is divided into four parts. The first part deals with the description and explanation of the general principles of switching concept amplifiers. The second part is occupied with design of Class-D amplifier, a description of each block and calculations. A significant part of proposal of amplifier is based on simulations from programs Pspice and Filter Free. In the third part deign of power unit is discussed. The last part is focused on the measurement results on a prototype device.
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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