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Device control based on touch-sensitive capacitance-sensing circuits
Matula, Rastislav ; Kubánek, David (referee) ; Hanák, Pavel (advisor)
The primary objective of this master’s thesis is to discuss a design and development of proximity touch control panel, which contains two simulated buttons and one rotary slider simulating functions of the potentiometer using specialized sensor controllers. The first part is describing functions and different technologies used to create touch sensors. It also introduces its usage in practice, advantages and disadvantages of different technologies which provides the readers with basic theoretical knowledge and introduction into the touch sensors. The second part as follows describes the definition of Integrated Circuits MPR083 and MPR084, outline of the features and methods of their functions. Displays internal connection of these circuits and describes forms of the serial communication with microcontroller connected to I2C bus. In these part there are in details described individual internal registers of these Integrated Circuits and theirs typical setups. It shows how it is possible to use the external interrupts and examples of their practical application. In the last chapter of these thesis is described the layout of the individual modules and construction of the whole designed device. The work is introducing two different concepts of programming the microcontrollers and consequently also construction of the appropriate ISP and JTAG programmers. It also introduces construction of the display units for visual feedback with the user and approach of the communication for the control LED matrix and graphical LCD display. The main part of this thesis is the construction of the control circuit, which includes key part, microcontroller ATmega16. It also presents the description of the program written in development environment AVR Studio in programming language C and his specific functions. In conclusion of the thesis are listed real measured behavior of the communication on I2C bus and their description.
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Testing and charging of accumulator cells
Sršeň, Jan ; Kubánek, David (referee) ; Lattenberg, Ivo (advisor)
Direction of the master's thesis is design and construct electronic device for testing available accumulators. Than there are in detail subscribe some metods of charging cells and their right usage to select type of cells. Also eventually problems that can become if the choice is false. Next part contains description of principles as several type accumulator works and their loading characteristic witch are important know for choose the best testing way. The most important knowledge is detection of stop point charging when accumulators are charged and following charging can be dangerous. Because there are more methods to detect this point so in thesis are overwrite. The most important part is design of tester. That is mapped to more segments witch communicating together. Controller part of intelligent tester contains ATmega128 microcontroller so there is present a passage of program code. Last section of master's thesis describe a physical consruction and explain division for smaller parts and hole process of tester function.
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Nonlinear Circuits with Current Operational Amplifiers
Rudolf, Jaroslav ; Vrba, Kamil (referee) ; Kubánek, David (advisor)
This master’s thesis is about replace voltage feedback operation amplifiers (VFOA) by current operational amplifiers (COA), current conveyors and current followers (CF). In introduction are mentioned word or two about operational amplifiers and their basic circuit such as invert and non-invert amplifier and there are described formulas for calculation gain. In another chapter is described COA, his properties and advantages compared to VFOA. Next there are described basic circuits of current conveyors. Follows chapter where is described replace VFOA by COA and conversion between them. In another part is at first deal with models of COA and CF in simulating program and then replace VFOA by COA. There are some simple circuits for example precision rectifiers and function generators and their simulations before and after replace VFOA by COA. In full-wave rectifier with current conveyors is made detailed simulation with some input voltages and frequencies. In last chapter is detailed described multi-mode rectifier with current follower. There is table witch described all modes of rectifier. For example voltage mode, current mode and mixed mode with half- or full-wave rectifier. There are simulations for all modes. Primarily are made detailed simulations voltage and current mode. In another part of this chapter is made measurement voltage and current mode. There are measured functions as half- and full-wave rectifier. There are described parameters of rectifier from measured values. In the end are these values compared with values from simulations.
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Synthetic Circuit Elements with Higher-Order Immittance with Controlled Current Sources
Popelka, Petr ; Vrba, Kamil (referee) ; Kubánek, David (advisor)
This thesis deals with design and use synthetic circuit elements with higher-order immittance with controlled current sources to implement the frequency filters. Controlled current sources which are derived from the voltage variations are presented. They are current follower, current invertor and current operational amplifier. Low-pass and high-pass filter which are used synthetic elements are simulated on computer. The influence of real properities of active elements and passive elements tolerances on filter functionality is investigated. Selected circuit of frequency filter is realized and measured the frequency characteristic.
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Active Frequency Filter Design Methods Based on Passive RLC Prototype
Pisár, Peter ; Vrba, Kamil (referee) ; Kubánek, David (advisor)
The aim of this diploma thesis is to design active frequency filters based on passive RLC prototype. Three methods of the design of active filters and active functional blocks of electronic circuits working in current or mixed mode are used to this purpose. These blocks allow to process electrical signals with frequencies up to low tens of megahertz. In addition they feature for instance with high slew rate and low supply voltage power. Active high-pass and low-pass 2nd order filters are designed using simulation of inductor by active subcircuit method. Grounded and subsequently floating synthetic inductor is made with the current conveyors in the first case and with the current operational amplifiers with single input and differential output in the second case. This method advantage is relatively simple design and disadvantage is great quantity of active functional blocks. Active filters based on passive frequency ladder 3rd order filter while only one floating inductor is connected, are designed with circuit equation method. In the first design differential input / output current followers are used and in the second case current-differencing buffered amplifiers are used. This method benefits by smaller active blocks number and disadvantage is more complex design of the active filter. Active filter based on passive prototype of low-pass 3rd order filter with two floating inductors is designed with Bruton transformation method. Final active filter uses current operational amplifiers with single input and differential output which together with other passive elements replace frequency depending negative resistor, which arise after previous Bruton transform. This method usage is advantageous if the design consists of larger quantity of inductors and less number of capacitors. High-pass 2nd order filter is simulated by tolerance and parametrical analyses. Physical realisation utilising current feedback operational amplifier which substitute commercially hardly accessible current conveyors is subsequently made. Measurements of constructed active filter show that additional modifications, which allow better amplitude frequency characteristics conformity, are necessary.
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Universal active elements and their usage in frequency filters
Vencálek, Roman ; Kubánek, David (referee) ; Herencsár, Norbert (advisor)
This master’s thesis deals with the advanced universal modern active elements, such as the current and voltage conveyors. The problem with small bandwidth has been fixed due to the quick development in recent years. Current and voltage conveyors are still being researched. The good properties of conveyors promise their possible commercial usage in the future. For the research of current conveyors we can use parts of other integrated circuits and thus get elements with similar properties. This thesis suggests how to make an active filter using the DBTA and FDBTA elements which were created by “combination” of the universal current and voltage conveyor. Simulations were carried out on selected circuits containing the DBTA to verify their properties. It was for finding out about their behaviour in real applications that the circuits were constructed. This enabled the comparison of the results acquired from the simulation programs with the ideal behaviour of the elements and with the models simulating real properties against the values acquired by measurements of the circuits.
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Measurement of Transfer and Immittance Characteristics of Active Circuit Elements
Marek, Pavel ; Vrba, Kamil (referee) ; Kubánek, David (advisor)
This diploma work deals with active circuit elements and proposals of methods for measuring of some parameters of these elements. In the opening part the work deals with general classification of elements used in electronic circuits, ideal and real current sources and power supplies. Further there are stated basic parameters and characteristics presented by producers in a catalogue sheet for active elements MAX435, OPA660, AD844 and MAA741 element which already belongs to the history of IC. Main attention is paid to active circuit elements with current sources driven by CCCS (Current Controlled Current Source) and AD844 (high speed monolithic operational amplifier). In the work there is described a method for determining of selected parameters of active elements with CCCS. Examined parameters were frequency characteristics of current transfer, input impedance and output impedance. The proposed method was verified by a computer simulation on above mentioned active elements by means of PSpice software. Findings along with the description are summarized at the end of the work. In the closing part of the work there is undertaken a real measure of AD844 element based on the proposed method and the findings are compared with particular simulations. However, at first a flat connection board was made by means of EAGLE software and then the measure was performed on it.
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Communication Systems with Digital Modulations
Spáčil, Jan ; Kubánek, David (referee) ; Číž, Radim (advisor)
The purpose of this semestral project is to explain the basic issues of simple digital modulations through the creation of simple digital modulations using direct digital synthesis. It begins with a short review of digital modulation theory and the theory about direct digital synthesis. All the technical documentation is attached, including schematics and boards of functional modulator.
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QAM Modulator
Duffek, Luděk ; Kubánek, David (referee) ; Číž, Radim (advisor)
The thesis focuses on consideration of possible ways how to realize multi-state modulators for a laboratory instrument. This instrument will illustrate signals, which partake on generation QAM modulation. The design of the laboratory instrument includes theoretic schemata and the execution of a prototype. There are theoretical facts of multi-state signals and multi-state modulations in this thesis. A simple block diagram of the laboratory instrument is made by the theory of creating quadrature amplitude modulation. For each block there are made several schemata, which are compiled to the global scheme. A printed circuit board and the structure items are made by the aid of the global scheme. The next part is devoted to a software facility for a used microprocessor, which ensures the whole function of the laboratory instrument. The final section deals with measuring, which checks the function of the modulator and the right setting coder’s constellation diagrams.
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Instruction application for Internet environment
Bartík, Rastislav ; Herencsár, Norbert (referee) ; Kubánek, David (advisor)
Ajax is quite new technology in world of web pages creation. In fact, it consits of more programming techniques like Javascript, PHP and XML. The main advantage of this technique is contacting server side on the background. This paper is focused on creating educational application for internet environment. There is written about solution for user’s interface and interface for administration.
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