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Design of magnetic bar-code read head
Kadlčík, Libor ; Drexler, Petr (referee) ; Mikulka, Jan (advisor)
Magnetic bar-code is composed from ferromagnetic bars printed on a substrate. The amount of ferromagnetic material is low, therefore reading magnetic barcode requires sensitive methods. Principle of methods of sensing both low-intensity magnetic field (fluxgates) and detecting low concentration of ferromagnetic material (resonant circuit, differential sensor) will be described. There are sensors producing frequency-modulated signal, therefore we focus on frequency demodulators as well. Signal acquired by sensor suffers from convolution distortion, reconstruction methods will be introduced. The assembled device consists of sensing oscillator, frequency demodulator, amplifier and reconstructing circuit. Frequency demodulation is done by phase-locked loop or differential demodulator. Reconstruction is based on detection of inflection points, producing square signal (representing bars of barcode). Design of these blocks is described. The device is able to read magnetic barcodes and reconstruct convolutionary distorted acquired signal. The differential demodulator exhibits low noise and low temperature drift (contrary to phase-locked loop). Signal produced by reading 2 mm wide bars is reconstructed without any problems, bars of width less than 1 mm cause troubles in certain cases (due to high degree of convolution distortion).
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Function Generator
Suška, Jiří ; Kraus, Michal (referee) ; Kunovský, Jiří (advisor)
This bachelor's thesis dissert on different types of oscillators, their functions and usage in everyday life. This thesis also contains comparing several types of oscillators and possible concepts for function generator whitch will be used in course IPR.
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FITkit Music Synthesizer
Melichar, Vojtěch ; Minařík, Miloš (referee) ; Vašíček, Zdeněk (advisor)
This bachelor's thesis deals with sound synthesis methods and with design of a synthesizer for FITkit platform. In the first part of the thesis, there are described methods of sound synthesis and the history of sound synthesis is also stated here. Next part contains a brief characteristic of sound chip SID 6581. In the next part of the thesis, there is a design of each part of the synthesizer: oscillator, envelope generator, voice and filter. Then, these components are put together to make up an synthesizer. Correctness of the implementation is verified by a simulation in ModelSim 6.6d. Individual components are simulated separately and then in mayor groups.
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Application of the syntetic blocks in the electronic circuit synthesis
Labudík, Marek ; Dostál, Tomáš (referee) ; Petržela, Jiří (advisor)
n project is investigated synthetic coils and FDNR, circuits are first simulated in a snap, which I obtained the graph of the input impedance at the frequency and formula to calculate the impedance. The results of this simulation were used for the simulation program PSPICE, the districts where I was compared with the equivalent circuit, which I design on the formula of the snap. Some of the investigated synthetic and FNDR coils were then used for simulation of the oscillators.
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Position Inductive sensor
Kořistka, Petr ; Procházka, Petr (referee) ; Huták, Petr (advisor)
Bachelor thesis deals with desing and construction of the inductive sensor. It shortly describes the history, advantages and disadvantages. Next there is developed principle of basic sensors working on the basis changes of inductivity and qualities of scanned materials. Major part of work was desing of individual parts of sensor essential to its correct function. It includes oscillator, rectifier, PI regulator, supply of tension and evaluation circuits. In the practical part was suggested PCB for individual parts of sensor. Measurement and processing of results were done.
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Study of Electronic Control and Real Behavior in Variable Filtering and Oscillating Applications of Modern Active Elements
Šotner, Roman ; Ondráček, Oldřich (referee) ; Martínek,, Pravoslav (referee) ; Petržela, Jiří (advisor)
The thesis deals with electronically adjustable and configurable applications of the modern active elements. In the field there were presented various active elements in applications of the analog filters and oscillators which stem from basic and more or less similar principles of circuit synthesis and design. However, there is not provided study of real behavior in detail and in most cases electronic control of the various parameters in application is not verified. In the precise design of application is very important to identify problematic features and determine how much it influences functionality of the device. In this work several filtering structures based on common and modified synthesis principles (integrator loops) are compared in the view of multifunctionality, configurability, variability, kind of used electronic control and impact of influences of real elements on behavior. There are used standard methods like adjusting of variable transconductance, intrinsic value of current input resistance and not so common method based on variable current gain in design of modified and improved multifunctional filtering circuits. The last method of mentioned control enabled to find quite unique filter which allows continuous electronic change of transfer from band-reject to all-pass filter of the 2nd order without reconnection. It is much simpler than previous and more common integrator loops. Larger part of this work is focused on electronically controllable oscillators mainly on quadrature types. There is presented several very simply and elementary realizations which require minimal number of active and passive elements. There are also slightly or more complicated solutions which remove some drawbacks of mentioned simpler variants. First of all there is given attention on study of real behavior which make obvious different problems with mutual dependence of oscillation condition and oscillation frequency, dependence of produced amplitudes (quadrature types) on parameter which is controlling oscillation frequency, influence of this parameter on oscillation condition, etc. In the framework of this part of the thesis there was introduced a novel modification of current conveyor transconductance amplifier (CCTA) so called current-gain-controlled current conveyor transconductance amplifier (CGCCCTA). Requirements for novel applications in the field of oscillators for newly developed controllable current amplifier and digitally controllable current amplifier (DACA) at the Department of Telecommunication FEEC BUT lead to creation of several chapters of this work where mentioned active elements can be used. The important contribution of this work (for practical approach) is also experimental testing of most of designed circuits and determination of exact design equations and rules which take into account real behavior of circuits and confirm results obtained from experiments.
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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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Applications of multi-output active elements in current-mode
Maňas, Stanislav ; Jeřábek, Jan (referee) ; Šotner, Roman (advisor)
Bachelor's thesis deals with analyzing the characteristics of the block in current mode CCII and its applications. The first part is devoted to the theory of CC block, the theory of CCII block his peripheral involvement and exploration properties. The second part is a third model levels and this is carried out sensitivity and tolerance analysis of individual involvement. The third part is a block CCII surveyed as part of participation frequency filters and oscillators. One involvement has been experimentally tested. At the end of each subsection is obtained by a comparison of the characteristics of individual involvement.
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Impulse generator
Buš, Ondřej ; Drexler, Petr (referee) ; Kubásek, Radek (advisor)
This thesis deals with the question of generating very short voltage impulses. At first it considers the most used behaviors of impulses and their mathematical description. Then it covers various principial circuit connections, which are used for generating short impulses. There is a scheme of controlled generator described in detail in this work, which is being used for exciting the forming circuit. Part of this work is also a description of program equipment, scheme of connection with designed desk of printed circuit. Description of construction of three shape circuits based on theoretical findings follows. Every solution is compared to each other upon time and frequency domain.
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Technical Analysis
Kratochvíl, Bohumír ; Dřímal, Dominik (referee) ; Novotná, Veronika (advisor)
Master´s thesis goal that the author hopes to achieve is a design of an application aiding stock technical analysis based on identified needs. Based on analysis regarding modules for technical analysis of current trading platforms, I found out there is a certain space for improvement. Implemented trading rules and technical indicators of the application itself are further examined in terms of prognostic success rate on historical data. Selected chapters of technical analysis are fundamental base for this master´s thesis.
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