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Audio pre-amplifier for two satellites and subwoofer
Štaud, Stanislav ; Brančík, Lubomír (referee) ; Kratochvíl, Tomáš (advisor)
The aim of this thesis was to design, simulate and construction audio pre-amplifier for two satellites and subwoofer and monolithic amplifier for subwoofer in the class AB. Audio pre-amplifier provides bass, treble and switch loudness volume control. It includes subsonic filter and active crossovers Sallen-Key with approximation Linkwitz-Riley. There are low noise operating amplifiers LM833 and TL081 at the place of active amplifiers with very low distortion. End-amplifier can delivers power 50 W to 4 ohms. Of consists delayed switch speaker and supports security against direct voltage on the output of amplifier.
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Measurement of diversity broadcasting in DVB-T2 standard
Koblischka, Vítězslav ; Kratochvíl, Tomáš (referee) ; Polák, Ladislav (advisor)
This bachelor thesis compares standards for digital and terrestrial television broadcasting of first-generation DVB-T and second-generation DVB-T2. It focuses particularly on the impact of interference in transmission media simulated by transmission channels for fixed, portable and mobile reception of terrestrial digital signal. Furthermore, the thesis compares SISO broadcast with the diverse MISO broadcast in DVB-T2 standard and evaluates the impact of the mode on error rate depending on the selected transmission channel and systems parameters that were used.
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Simulation of the DVB-C2 transmission
Chovaneček, Libor ; Fliegel, Karel (referee) ; Kratochvíl, Tomáš (advisor)
The theme of this thesis is simulation of DVB-C2 transmission. The first part of this thesis is focused mainly on theory, where it describes differences between digital and analog television transmission. The project also explains principle of operation DVB-C and DVB-C2 systems with focus on channel coding a modulation. Application for simulation of DVB-C2 transmission, which is developed in the MATLAB environment is described in the second part. The last part of this thesis includes results of simulations of DVB-C2 transmission and their comparison with measured values of DVB-C transmission.
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Advanced algorithms for compression of video sequences with ultra high resolution
Soukeník, Ondřej ; Kratochvíl, Tomáš (referee) ; Polák, Ladislav (advisor)
This bachelor thesis provides an overview of advanced video codecs and explores their applicability for compression ov videosequences in ultra high resolution (UHD). The thesis is divided into two parts, theoretical and experimental. The theoretical part of the thesis gives an overview of advanced video codecs for video compression. Furthermore, objective metrics used for evaluation of the quality of a compressed video are briefly described. This part of the thesis also contains a detailed description of the created tool, employing a reference implementation of the selected video codecs, for easy compression of video sequences in UHD. This tool is used in the experimental part to compress different video sequences. The compression efficiency of each video codec is evaluated in terms of different objective metrics. Furthermore, the Bjntegaard Delta analysis is employed to obtain infromation about the compression efficiency of the used video codecs.
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Two-way stereo speaker system
Kočvara, Pavel ; Polák, Ladislav (referee) ; Kratochvíl, Tomáš (advisor)
The Bachelor thesis deals with design of a passive two-way stereo speaker system with performance 50 W RMS / 8 for normal domestic use. With respect to its sensitivity 90 dB/W/m mid-range speakers Beyma 5MP50/N and tweeter Beyma T2030 were used. The enclosure is a type of bass-reflex and it is made of MDF material with internal damping from polyurethane coat.
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RF detection method of explosives and drugs - NQR
Motyčka, Lukáš ; ČR,, MBA - ÚPT AV (referee) ; Kratochvíl, Tomáš (advisor)
The thesis deals with RF spectroscopic methods, which are applicable for the detection of hazardous substances such as explosives or drugs. Particular attention is focused on promising method of nuclear quadrupole resonance. Abroad this method has recently been applied in the detection of energetic materials in hazardous locations. The cornerstone of the nuclear quadrupole resonance is to evaluate the interaction between electromagnetic radiation, in the range of medium to very short waves, and the researched substance. Observed parameter are the resonant frequencies of the substance. Spectral analysis of signal is used for their evaluation. Resonant frequencies are always typical for the crystalline structure, therefore every explosive or drug is clearly identifiable by this method.
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Design of switching low-frequency power amplifier
Janáč, Josef ; Kratochvíl, Tomáš (referee) ; Brančík, Lubomír (advisor)
This bachelor project maps out switching technologies used in LF power electronics and gained information was consequentially used to design switching lf power amplifier as independent unit. Content of design is LF power amplified level, working on switching technology principle. Correction pre-amplifier with possibility of adjusting volume, balance h/l frequency and switching power supply is content as well too. Next part of project is familiarization s design program Eagle and optimizing program for switching power supply PXLS expert and creating constrictive basis for complete device. Last part of project is basically activation all functional part of device in one unit. Than measurement basic parameters on created functional device, graphical elaborating measurement-gained values and confrontation with catalog values. Conclusion of this project is evaluation achieved results in compare with supposed result of project.
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Audio power amplifier with audio processor and FFT analysis
Kubáň, Marián ; Frýza, Tomáš (referee) ; Kratochvíl, Tomáš (advisor)
This thesis is concerning about design of an audio power amplifier for home listening. Amplifier involves two audioprocessors, the first one chooses one of the four avaliable audio stereo inputs. The second just sets the considered shape of frequency characteristic of one of the picked audio signal. As soon as tha signal leaves the audiprocessors, its path is divided. First route leads to the power amplifier and second one ends up in the analog to digital converter. Both audiprocessors are adjusted via IIC line by 8-bit microcontroller. The primary role of microcontroller is to enumerate frequency coefficients through the fast fourier transformation with Cooley-tukey algorithm. Result of FFT is then displayed on graphical display unit. The whole desired parametres as volume, trebble, input selection, atc., are driven with one controller and that is a rotary encoder.
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Audio D/A converter with external control using microcontroller
Špaček, Jan ; Stifter,, Jiří (referee) ; Kratochvíl, Tomáš (advisor)
This diploma thesis deals with the design of a laboratory measurement tool with ADC converter for audio and low frequency signals. In the introduction part a theoretical background of the ADC and DAC conversions are outlined. In the next chapters the technical solution of the laboratory converter is presented, including DAC with integrated circuit AD1852 and completed with digital audio receiver CS8416. This circuit secures compatibility with external audio devices with digital interfaces, like SPDIF or AES3. The digital receiver and audio DAC are added with serial communication interface for setup of the most audio and input parameters. This setup is operated by external microcontroller ATmega32 and original firmware. The thesis contains block diagram and schematic layout of the laboratory converter, including complete technical documentation for the construction and design.
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