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Design of Input Stage for Bi-Amp Loudspeaker System
Ryšavý, Jindřich ; Hanák, Pavel (referee) ; Schimmel, Jiří (advisor)
The thesis discuss the desing of active crossover for loudspeaker systems. There are described two most common topologies forming active filters and their comparison. Also is there shown way how to desing transfer functions to achieve flat overall transmission, then computing components bases on topology. All that is shown on example. Then are discussed different ways how to correctly receive analog or digital sound signal and handle with them. Example desing is then shown.
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Advertising LED RGB Tube with Control Unit
Frelich, Marek ; Fedra, Zbyněk (referee) ; Frýza, Tomáš (advisor)
This project discusses design of LED RGB tubes, which can be driven by asynchronous serial line. The light color of the LED tubes can be controlled in a several segments of tubes. There is made a design of control unit for driving LED tubes, which contains circuits for receiving and detection of audio signal, receiving of protocol DMX512 and also driving of LED strips. For the microprocessors there is also created a software which ensures a communication between the control unit and LED tubes, driving LEDs in the tube and creating various lighting effects.
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Adaptive active band - pass
Velička, Pavel ; Murina, Milan (referee) ; Sedláček, Jiří (advisor)
The aim of this thesis is to find and propose solutions adaptive ARC frequency bandpass filter, where it will be possible to change the bandwidth and tuning the center frequency. Centre frequency will be tuning in the range from 10kHz to 100kHz. Bandwidth is tunable to the maximum range that will enable us to select involvement. The thesis selected two methods of implementation of the filter. It made the comparison and selection of improved variants. Thesis includes calculations of the resulting variant filter and describes how to tune the filter, and then simplify the tune selected filter. Bachelor thesis includes a complete filter design for its implementation. A suitable method of electronic tuning were selected digital potentiometers controlled programmed microcontroller. This method was also subsequently implemented.
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Low Voltage Low Power Analogue Circuits Design
Alsibai, Ziad ; Horský, Pavel (referee) ; Ďuračková, Daniela (referee) ; Khateb, Fabian (advisor)
Disertační práce je zaměřena na výzkum nejběžnějších metod, které se využívají při návrhu analogových obvodů s využití nízkonapěťových (LV) a nízkopříkonových (LP) struktur. Tyto LV LP obvody mohou být vytvořeny díky vyspělým technologiím nebo také využitím pokročilých technik návrhu. Disertační práce se zabývá právě pokročilými technikami návrhu, především pak nekonvenčními. Mezi tyto techniky patří využití prvků s řízeným substrátem (bulk-driven - BD), s plovoucím hradlem (floating-gate - FG), s kvazi plovoucím hradlem (quasi-floating-gate - QFG), s řízeným substrátem s plovoucím hradlem (bulk-driven floating-gate - BD-FG) a s řízeným substrátem s kvazi plovoucím hradlem (quasi-floating-gate - BD-QFG). Práce je také orientována na možné způsoby implementace známých a moderních aktivních prvků pracujících v napěťovém, proudovém nebo mix-módu. Mezi tyto prvky lze začlenit zesilovače typu OTA (operational transconductance amplifier), CCII (second generation current conveyor), FB-CCII (fully-differential second generation current conveyor), FB-DDA (fully-balanced differential difference amplifier), VDTA (voltage differencing transconductance amplifier), CC-CDBA (current-controlled current differencing buffered amplifier) a CFOA (current feedback operational amplifier). Za účelem potvrzení funkčnosti a chování výše zmíněných struktur a prvků byly vytvořeny příklady aplikací, které simulují usměrňovací a induktanční vlastnosti diody, dále pak filtry dolní propusti, pásmové propusti a také univerzální filtry. Všechny aktivní prvky a příklady aplikací byly ověřeny pomocí PSpice simulací s využitím parametrů technologie 0,18 m TSMC CMOS. Pro ilustraci přesného a účinného chování struktur je v disertační práci zahrnuto velké množství simulačních výsledků.
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Application possibilities of controllable current amplifier
Bradáč, Josef ; Koton, Jaroslav (referee) ; Jeřábek, Jan (advisor)
This thesis deals with the application using digitally controlled current amplifiers DACA (Digitally Adjustable Current Amplifer), which was developed at the Department of Telecommunications FEEC in cooperation with ON Semiconductor in 2010. In introduction is decribed the topic of active filters and oscillators. Farther active current components, besides DACA are described current conveyor UCC (Universal Current Conveyor), current amplifier DO-CF (Dual-Output Current Follower), MO-CF (Multiple-Output Current Follower) and FD-CF (Fully Diferential Current Follower) and operational transconductant amplifier BOTA (Balanced-Output Operational Transconductance Amplifer) and MOTA (Multiple-Output Operational Transconductance Amplifier). The following is a compilation of theories circuits using signal flow graphs, which are designed using a simulated filter circuits to control the cutoff frequency or the quality factor. Then design and simulation with auxiliary oscillator circuit AGC for controlling the oscillation frequency. Simulations are conducted with ideal models and with models that include some real properties. The conclusion of this work is devoted to the printed circuit board design for a selected filter circuit realization and measurement.
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Frequency filters using current active elements
Homola, Radek ; Lattenberg, Ivo (referee) ; Koton, Jaroslav (advisor)
This master´s thesis is about MO-CF, DCCA and CC frequency filters with current active elements proposal. Current active elements, their features, structure and utilization are shown in introduction. A progress propose of universal filter is described in thesis. With the use of active elements has been established an universal filter with basic parameter changes capability (quality and limit frequency). SNAP software was used in this propose and the characteristics simulation have been done in OrCad-PSpice. For control changes of quality and limit frequency was used active element DCCA. The main circuit board of universal controlled filter was made with the EAGLE software. Created sample was measured for each type of filter, the different quality and limit frequency. These values were compared with simulated values of the filter.
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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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Analog spectrum analyzer
BUŠEK, Pavel
The task of this bachelor thesis was to build and measure a simple spectrum analog analyzer. Analyzer works with active frequency filters. The first part of the thesis introduces principles of the theory of frequency filters. The second part deals with development of eight-pass frequency analyzer and measurement of its parameters.
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