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Design and Implementation of Active Loudspeaker System with Digital Input
Uchytil, Filip ; Balík, Miroslav (referee) ; Schimmel, Jiří (advisor)
The work is focused on a design of an active loudspeaker system with a bi-amp amplifier and a digital input. There is described the theory of a loudspeaker enclosure design and its practical implementation. Furthermore the work deals with a design and construction of input circuits such as a preamplifier, Baxandall tone control, active crossover, all-pass filter and S/PDIF. On the basis of the amplifier´s theory the optimal construction of amplifiers and their design are selected. The complex design of the loudspeaker box is devised so that it would reach a maximum acoustic power during the preservation of a low distortion.
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Design of class AB stereo audio power amplifier
Zatloukal, Tomáš ; Polák, Ladislav (referee) ; Brančík, Lubomír (advisor)
The following work deals with design of class AB low-frequency amplifier, which is appropriately supplemented by correction Pre-amplifier and inrush protection circuit. The original schematic from prof. Leach was edited to fulfill task and to be easily completed from discrete components. The result of this work is the final design of power amplifier and correction pre-amplifier, protection circuit for speakers and power supply. As a next part, the design of printed circuit boards will be described together with assembling and mounting of boards in a construction box. Power amplifier will be verified by simulation and hardware measurements.
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Power audio amplifier with two-way speaker system
Rystvej, Matej ; Petržela, Jiří (referee) ; Kratochvíl, Tomáš (advisor)
The aim of this bachelor thesis was a design of a stereo amplifier with an appropriate loudspeaker system for home listening. The amplifier has the ability to be switched over between high and low output power mode. This means it is possible to be used also with an other loudspeaker system with lower input power rating, and it will be prepared for possible future implementation of an active frequency filter, which will fit the frequency response to this designed loudspeaker system by amplifying some frequencies. This thesis contains design of the softstart circuit, power amplifier, preamplifier circuit, the output power switch, the delayed loudspeaker connecting circuit and the loudspeaker system.
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Class D audio power amplifier
Kaláb, Lukáš ; Petržela, Jiří (referee) ; Kratochvíl, Tomáš (advisor)
This project aims on completed design and consequential realization of prototype of the class D audio power amplifier. Amplifier works for home listening and should power at 2 x 50 W. The machine contains finall degree, correcting pre-amplifier and power supply. The basis for realization of the design (connection diagram, design of printed connections boards, distribution and list of parts) are made in Eagle software. Mechanic configuration of all parts in the body of the amplifier is also part of the work.
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Parameters of Communication Systems Based on OFDM-CDMA
Blumenstein, Jiří ; Kocur,, Dušan (referee) ; Baudoin, Genevieve (referee) ; Fedra, Zbyněk (advisor)
Cíl disertační práce leží v oblasti modelování a vyhodnocení bezdrátových komunikačních systémů s dvojrozměrným rozprostíráním signálu a jejich klíčových parametrů v závislosti na vybraných vlastnostech moderního bezdrátového komunikačního řetězce. Výzkumné metody použité v této práci spočívají především ve vývoji softwarového simulátoru pro prostředí Matlab, s jehož pomocí, a s využitím statistického přístupu, jsou navržené algoritmy ověřeny. Dále je použit simulátor fyzické vrstvy dle 3rd Generation Partnership Project Long Term Evolution (3GPP LTE), vyvinutý na Technické univerzitě ve Vídni. Tento představuje ideální platformu pro implementaci metody dvojrozměrného (2D) rozprostírání a její vyhodnocení s přihlédnutím k současným bezdrátovým komunikačním systémům. Zjištění prezentovaná v této práci představují především ověření účinnosti systému nazvaného jako Variable Spreading Factor - Orthogonal Code Frequency Division Multiplex (VSF-OFCDM), který využívá principu 2D rozprostírání signálu a zjištění, že VSF-OFCDM systém překonává systémy využívající Orthogonal Division Frequency Multiplex (OFDM), nebo Code Division Multiple Access (CDMA). Dále byla navržena metoda 2D rozprostírání signálu v systému LTE, kde se též potvrdila její účinnost. Díky účinnějšímu potlačení vlivu rychlé variace přenosového kanálu v závislosti na frekvenci a čase, dosahuje systém VSF-OFCDM znatelně vyšší datové prostupnosti.
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Stereo equalizer with spectrum analyzer
Náhlík, Ondřej ; Šotner, Roman (referee) ; Kratochvíl, Tomáš (advisor)
This bachelor’s work is focused on design of ten band analog stereo equalizer, which is solved by using an active band-pass filters of 2nd order. Simulated output signal isn‘t rippled more than ± 1 dB at zero amplification and can be amplified at maximum ca. ± 8 dB. Prototype of equalizer is then built and it’s characteristics are measured. The circuit of an integrated power amplifier working in the class AB is solved in the next part of this work. Amplifier is then built and it’s characteristics are measured. In the last part of this work, there is described function of a spectral analyzer which is then designed, built and programmed. The analyzer uses the Fast Fourier transform (FFT) and resulting spectrum is displayed on a display.
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The Design Methods of Equipments for Audio
Kondler, Radim ; Vrba, Kamil (referee) ; Mišurec, Jiří (advisor)
The work is focused on equipment used in audio, such as a loudspeaker crossovers, amplifiers and preamplifiers. There are theoretically described loudspeaker crossovers, their parameters, types of structures derived from the frequency filters with their parameters. Further deals about audio amplifiers and both voltage and power, their theories, parameters, and distribution.
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Quadrophonic audio amplifier for home use
Gavlák, Antonín ; Kratochvíl, Tomáš (referee) ; Brančík, Lubomír (advisor)
This bachelor work describes the design quadraphonic audio amplifiers for home use that works in class AB. The proposal includes a correction preamplifier integrated circuit LM1036 and power amplifier monolithic integrated circuit LM3886 to the output impedance of 8 with appropriate cooling power element. The work also deals with suitable power supply units and soft start circuit for the amplifier. The work contains materials for the construction of a functional prototype of the low-frequency power amplifier and the results of laboratory measurements.
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High Efficiency Microwave Power Amplifiers - Laboratory Experiment
Gajzler, Jakub ; Svačina, Jiří (referee) ; Urbanec, Tomáš (advisor)
This Diploma thesis deals with methods that increase efficiency of transistor amplifiers. In the first part of the thesis we describe theoretical background of the constructions of power amplifiers. At first we deal with the classical method that is concerned with a change of position of the static operating point. Secondly we cover the multi harmonic manipulation method (MHM). This method is concerned with a proper loading of particular harmonic components and consequential shaping of voltage runs and currents on the collector. In the second part of the work we have constructed the substitutes of particular accesses. Constructed classes are AB, F and FMHM. Basic S parameters and output signal spectrum were measured. We can see from the calculated efficiencies AB = 11%, F = 16% a Fmhm = 18%, big increase of efficiency F and FMHM only by changing output network.
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Design of switching class audio power amplifier
Bronec, David ; Kratochvíl, Tomáš (referee) ; Brančík, Lubomír (advisor)
This bachelor thesis is dealing with the issues of the switched category output amplifiers and its aim is to design and to construct a stereo amplifier with the energy output about 100W. The amplifier is constructed in the switched category D. The design of the corrective preamplifier with the correction of depths, heights and the balance functions is also described. Furthermore, this thesis deals with the description of the switched power supply with the TOPswitch control circuit. The design is also supplemented by the simulations and the printed circuits of each part. There are also some photographs of the device and the measurement protocol is included too.
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