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Synthesis of Modern Structures of Frequency Filters
Friedl, Martin ; Hájek, Karel (referee) ; Brančík, Lubomír (referee) ; Sedláček, Jiří (advisor)
Within modern frequency structures, the filter frequency region of up to 10 MHz constitutes a promising research topic that currently attracts intensive attention of specialists interested in the problem. The main reason of this fact consists in that the rapid development of modern technology allows the production of innovated structures of the analog frequency filters required in the defined band. In this context, however, it is also necessary to refine the methods applied in the synthesis and optimization of these structures; such improvement should be carried out with respect to fundamental properties and usability of today's active elements (operational amplifiers with voltage feedback whose Gain Bandwidth Product ranges within units of GHz, operational amplifiers with current feedback, conveyors, transimpedance operational amplifiers). In this thesis, active blocks of synthesis inductors (SIs) and frequency dependent negative resistors (FDNRs) are examined in detail, and the author provides novel formulas to define the basic parameters of the dual circuits. Due emphasis was placed on optimizing the basic building blocks of the second order and defining the variation of their properties caused by the addition of modern active elements. The blocks were analyzed and modified in view of their possible use in higher-order circuits. For active filters of a higher order, simulations were performed to indicate the actual sensitivity of the cascade and non-cascade ARC structures. The following phase of the research comprised mainly the designing of several filters, and this activity was further completed with the verification of the methodology for the synthesis and optimization of higher-order loss ladder filters with modern active blocks. Special attention was paid also to the methods enabling the optimization of such filters, which are invariably based on RLC prototypes. In order to verify the theoretical conclusions, the author materialized a large number of sample optimized filters and measured their parameters. The closing section of the thesis describes the use of the filters in specific applications.
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Audio power amplifier 2 x 500 W
Petrgál, Filip ; Brančík, Lubomír (referee) ; Hruboš, Zdeněk (advisor)
This bachelor’s thesis deals with low frequency power amplifier, distribution, and involvement of important parameters. Furthermore, the second deals with the preamplifiers, power supplies, amplifier circuits protections and other additional modules. Elaboration includes simulated proposals to address preamp, power amplifier output stage as well as protection circuitin PSpice program. Proposes that these modules is shown in the detailed diagramdescribing the components.
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Design of audio power amplifier with Bluetooth connectivity
Bartoň, Jan ; Šotner, Roman (referee) ; Brančík, Lubomír (advisor)
This bachelor‘s thesis deals with the task of designing an audio amplifier, operating in class D, with a nominal output power of 2 x 80 W with Bluetooth connectivity, supplemented by an equalizer and a state display. A power supply and a user interface are designed as well. At first, research regarding audio amplifiers is made, followed by a more thorough description of class D operating principles. Afterwards the actual synthesis of the desired amplifier is presented, followed by the power supply design procedure. The correctness of the synthesis is later verified by simulations in PSpice and LTSpice. Theoretical design is then practically built, and its parameters are confronted with expected values by measurements.
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DC-AC converter 12 V / 230 V for car applications
Jezerčák, Martin ; Šebesta, Jiří (referee) ; Brančík, Lubomír (advisor)
This work deals with a proposal for increasing DC/AC inverter for use in cars to power electronic devices on 230 V. This work is divided into two parts, theoretical and practical. It consists of three chapters. In the first chapter I developed a voltage converter, its breakdown, a breakdown by function, and the usage of individual connections. The proposal converter with the integrated circuit IR2153 is described in the second chapter. In the third chapter I processed readings and I visualized graphical dependencies of converter that was produced and purchased.
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Active controllable frequency filter in current mode
Zbořil, Jan ; Petržela, Jiří (referee) ; Brančík, Lubomír (advisor)
The aiml of this work is to study the principles controllable frequency filters in the current mode. Is realized multifuctional current filter. Summarizes the general characteristic of the current components. Work focuses mainly on current conveyors CCII. Circuit is used here EL 2082 as a basic building element. The second chapter discussed the characteristics of filters, the third contains a description of the basic active circuit. The next chapter deals with the simulation, and the last presents the measured results.
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Model of MOSFET transistor in program SystemVision
Michálek, Branislav ; Brančík, Lubomír (referee) ; Kolka, Zdeněk (advisor)
This bachelor thesis deals with modeling of MOS transistor. The theoretical part of the thesis is dedicated to analysis of basic MOSFET structure and operation, basics of modeling in general, descriptions of SPICE models LEVEL1 and LEVEL3 and model parameters extraction by using the optimization technique. The realization part is dedicated to creation of static models for DC analysis for three specific MOS transistors in the form of netlist used in SPICE circuit simulators, using the model parameters, which have been obtained by using the optimization technique in Matlab. Validity of realized models is then verified by comparing of its characteristics, obtained from simulation in SystemVision program, with characteristics from transistor’s datasheets.
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Design and construction of audio power amplifier
Růžička, Jaroslav ; Kratochvíl, Tomáš (referee) ; Brančík, Lubomír (advisor)
This bachelor’s thesis is concerned with amplifier classes, integration end-level, protective circuits and concrete concept of class AB power amplifier, including concept of preamplifier and power amplifier. Features of designed circuits were simulated in PSpice software. These individual concepts of modules are connected with DPS. This thesis contains results of measurement and photos of amplifier.
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Backup power supply with solar cell
Hrubý, Michal ; Brančík, Lubomír (referee) ; Kubíček, Michal (advisor)
Due to the modern trends of energy production from renewable sources, this thesis deals with backup power powered solar cell. Analyzes the principle of operation of the solar cell, describes its technological development. Describes types of commercially available accumulators and their specific properties and the recommended charging. It then focuses on the description of the activities used DC-DC converters and their specifics. The aim of this work is to construct a backup power device that uses USB, independent of the electric distribution network.
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Design of preamplifier for guitar effects generation.
Müller, Radek ; Kratochvíl, Tomáš (referee) ; Brančík, Lubomír (advisor)
The topic of my bachelor's project is preamplifier blueprint for creation of certain guitar effects. Output signal from an electric guitar is often modified for musician's needs. My objectives are to discover options of signal modifications, electronical solution of preamplifiers and final effect on sound character. My targets are to design and construct two chosen guitar effects, which will distort the output sigal from an electic guitar. Both wirings will be tested by computer simulation and then will be compared with real circuit wiring. Its necessary to box up the printed circuit board and place control and signal elements to accesible place.
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Modeling of the unconventional functional blocks in Pspice
Zetík, Rostislav ; Brančík, Lubomír (referee) ; Petržela, Jiří (advisor)
This master´s thesis on theme Modeling of the unconventional functional blocks in Pspice deals with the design procedures of electronic elements models and should to help with their create. At the beginning the thesis theoretically describes how the models are created and what possibilities for modeling the program Pspice offers. There are drawn near the individual levels of model and their properties. The second main part of thesis shows practically step by step the design procedures of models of the operational amplifier, current and voltage conveyors, OTA, CDTA, immittance inverter and converter and logarithmic amplifier. There are created the models up to 4.th level, the ideal, resistive, frequency dependent and nonlinear. The basic transmission properties, input and output impedance are modeled this way. The created models with sufficient accuracy correspond to the parameters of the commercial elements. This thesis such shows the possibilities of the program for finding of values for model components like stepping or Optimizer tool.
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