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Filtering structures containing a fractional-order elements
Kubát, Pavel ; Kubánek, David (referee) ; Dvořák, Jan (advisor)
Bachelor work deals with fractal order frequency filters. The first part describes basic division frequency filters, the following part describes fractional order frequency filters and design of the circuit with fractal order. The following part contains active elements that are used for the design of the frequency filters. The last theoretical part shows design method for frequency filters, where signal flow graph is shown. Realisation, simulation and measurement are described in the practital parts.
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Audio signal dynamics processors and their involvement in laboratory teaching
Růžička, Matěj ; Koton, Jaroslav (referee) ; Kubánek, David (advisor)
This master’s thesis describes dynamics processors, their basic building blocks and parameters, as well as the differences between various types of processors. There’s also a description of the design process and the performed simulations of the audio compressor parts. The audio compressor is using the model of the integrated circuit THAT4305. For functionality verification the whole circuit was simulated. Due to the long-term unavailability of THAT4305, the design had to be altered for THAT4315. In the next step the PCB for the compressor was designed, manufactured and the device parameters were verified. Eventually the manual for a laboratory task and an exemplary protocol were formulated.
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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 local characteristics of passive electrical devices
Šikula, Radek ; Kubánek, David (referee) ; Tománek, Pavel (advisor)
Bachelor thesis is focused on the newly conceived local measurement of electrical or photoelectric devices characteristics. According to Moore's law dimensions of active components on the chips diminish. Therefore effort to obtain corresponding reduction of passive electrical components, while improving, or at least maintain their parameters, is also challenged. It turns out that the problems associated with device reducing are connected with existence of physical limits of materials, and ultimately with the impossibility to measure local properties of electrical components using conventional electric methods. Especially in the range of physical limits, a serious problem of defects in materials appears. Due to that the small size components can greatly affect the efficiency, performance, durability and reliability of devices. Measurements made on the passive and active components show a higher resolution of defects on the surface of selected parts than current methods allow. 1) It follows from the results of measurement on capacitors that there are several possible reasons why breakdowns occur, e.g. mechanical defects or the presence of impurities and/ or oxide crystals in the dielectric. 2) Measurements taken at a photodiode allowed visualize minority carriers current, and view their lifetime. Moreover, they also show that the minority carrier lifetime comes mainly from bulk recombination.
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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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RDS-TMC signal processing
Plch, Jan ; Kubánek, David (referee) ; Lattenberg, Ivo (advisor)
At the begining of my work is discourse about basic quality signal RDS, that is transmission by the help of radio signal. Described is way encoding, division to the groups as well as internal rules insider and per informative and preventive part block. Follows description obligatory content of all groups as well as description their content according to insider and version. Next chapter is devoted detailed description content groups news TMC which contain traffic and travelling informations . Described is basic space exploited for track telling. Follows explication obligatory part message and show transmission identifiers on data that are painted user. After it are circumscribed next optional data and their fission to the caregory. Mentioned are also possibilities fission broadcast messages on single-group or multi-gropup and their following management in acceptor. Final part work paies description activities created application servant for signal processing RDS-TMC with explication concurrence and functionality single function.
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Generating coordinate data for PCB X-ray machine
Popela, Vojtěch ; Kubánek, David (referee) ; Hanák, Pavel (advisor)
The aim of this thesis was to pick up with the structure of soldering pads positional data of PCB Phoenix X-ray Micromex 180 and then to create programs for export of input data for this device. Theoretical part of this thesis is dedicated to the description of X-ray equipment and also, to the issues of conversion of positional data, folowed by PCB manufacturing formats description. The first part of the thesis deals with the process of creating the User Language Program (ULP) for PCB design software Cadsoft Eagle, in second part a program was made program for exporting data from ODB++ format.
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Non-linear Circuits with Controlled Current Sources
Dolák, Jan ; Hanák, Pavel (referee) ; Kubánek, David (advisor)
This thesis treats of problems of nonlinear circuits. In introduction the basic possibilities of solving nonlinear circuits are described. Then the basic information on modern current active elements is mentioned, for example current follower, current operational amplifier and current conveyor. In the next part of this thesis the problem of real characteristics of semiconductor diodes is described, major attention is focused on reverse recovery time. Three various types of circuits with nonlinear elements are described in this masters thesis. The first type of circuits are diode precision rectifiers, the full-wave rectifiers containing voltage operational amplifier are most explored, current follower and other active components are described in previous chapters. Simulations in PSpice were executed for each of these circuits. Then the attention was devoted to increase of maximum working frequence. The minimum necessary amplitude of input signal was also analyzed. In the following part two designs of diode function converters are processed, function converter with voltage operational amplifier and function converter with current follower. For each of the diode function converters designed, simulations were executed to find their real properties. The variety of diode voltage limiters and diode current limiters are the third type of nonlinear circuits described, from which the upper limiter and double limiter are investigated in more detail. Simulations were executed for all limiters and their functionality and problems connected with their usage for limitation of high frequency signals were analyzed. In the last part of the thesis there is described the practical realization of precise rectifier, which showed the best ability to process high frequency signals of all investigated circuits. This circuit was realized so that it is able to operate in current and mixed mode. Measured values of real circuits were compared with values gained from the simulations.
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Power LED control using ATtiny
Martynek, Tomáš ; Kubánek, David (referee) ; Balík, Miroslav (advisor)
Target of this bachelor’s thesis is to develop suitable DC/DC converter for driving power LED with Atmel Tiny micro. There is PHILIPS white power LED – Luxeon Star/O as the light source used. Micro’s AD converter measures current through this LED. This value is used for current driving using PWM micro output. Whole device is accumulator powered, design allows usage of three AA alkaline batteries instead of NiMH accumulators. During design phase was choosing between 2 and 3 AA batteries power solution. Because of the longest working time, the final solution uses 3 AA batteries – in this configuration works the flashlight about 7 hours. Flashlight can charge NiMH batteries from external constant current power source. Micro controls whole charging process and disconnects accumulators from current source after full charge using method of negative voltage change. Timer method is backup method in case, when negative voltage drop is very small – the charging time is limited to max. 9 hours. Micro can detect bad or non-possible charged cells.
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