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Phase shifted harmonic oscillators for practical education
Hudec, Marek ; Petržela, Jiří (referee) ; Šotner, Roman (advisor)
This thesis focuses on designing a laboratory preparation for the study of phase-shift oscillators. The first part of the thesis comprises a theoretical discussion regarding the given problem. The laboratory preparation will include two types of oscillator circuits. An operational amplifier will be used as the amplifying element together with an RC feedback loop in one type of circuit whilst the other type will consist of operational transconductance amplifier employed as inverting amplifiers and generating feedback. The second part of the thesis includes the actual design of the preparation. The design process covers construction stage of the preparation, calculation of the component parameters necessary for oscillation to occur, simulations of the individual circuits along with THD analysis as well as with analysis of manufacturing variances. The second part of the thesis also contains the design of a separate block of all-pass filter. The simulation results will be verified experimentally, on a printed circuit board. In the last part of the thesis, I will evaluate and intercompare the theoretical, simulation and practical results.
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Music based electronic light effect
Grygar, Josef ; Staněk, Miroslav (referee) ; Šotner, Roman (advisor)
This work is focused on music baset light effect, it´s principles and possibilities of realization. Music based light effect can affect our perception of reproduced music. This work include design and realization of spectral analyzer, anti-aliasing filter and output power parts. Spectral analyzer uses Fast Fourier transform (FFT) to count resulting spectrum, which is displayed on LED bargrafs. In the theoretical part the priciples of analog to digital conversion are closer described. According to this information, selection of suitable microcontroller is discused.
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Analog nonlinear function structures for educational laboratory purposes
Filko, Patrik ; Dvořák, Radek (referee) ; Šotner, Roman (advisor)
This master’s thesis deals with the design and the realization of a laboratory teaching device, which includes two-port parts with nonlinear transmission characteristics corresponding to quadratic, inverse quadratic and cubic functions. It also includes a more complicated design of a polynomial function converter that offers students a practical view of functions mathematically designed while verifying their accuracy in laboratory exercises. The whole concept is supported by the design of the power supply circuit and the harmonic signal generator. The individual features of this project are feasible from components commercially available.
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Digital controlled resistor
Sedlář, Petr ; Petržela, Jiří (referee) ; Šotner, Roman (advisor)
This master´s thesis deals with the design of the control circuits for digital potentiometers and their application in analog systems. Digital potentiometers are three-terminal resistors with an adjustable center connection. The digital potentiomneters enable to drive logic gates, LED drivers, LCD drivers, analog switches etc. Controlling of these mentioned devices is possible by the I2C 2- wire serial bus (invented by Philips). The digital potentiometers are used to control of the primary parameters like cut-off frequency and quality factor in the state variable filter and cut-off frequency in a passive filter. Both filters are simulated in PSpice and then compared with the measured results. Next parts of this master's thesis are a computer program and a exemplary protocol.
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Design of audio power amplifier with Bluetooth connectivity
Bartoň, Jan ; Šotner, Roman (referee) ; Brančík, Lubomír (advisor)
This bachelor‘s thesis deals with the task of designing an audio amplifier, operating in class D, with a nominal output power of 2 x 80 W with Bluetooth connectivity, supplemented by an equalizer and a state display. A power supply and a user interface are designed as well. At first, research regarding audio amplifiers is made, followed by a more thorough description of class D operating principles. Afterwards the actual synthesis of the desired amplifier is presented, followed by the power supply design procedure. The correctness of the synthesis is later verified by simulations in PSpice and LTSpice. Theoretical design is then practically built, and its parameters are confronted with expected values by measurements.
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Mixing audio console with microphone preamplifier
Mecerod, Václav ; Šotner, Roman (referee) ; Kratochvíl, Tomáš (advisor)
Bachelor’s thesis on the theme "Mixing audio console with microphone preamplifier" deals with the design of an audio device for mixing signals from different sources. After a short theoretical introduction to issues mixing audio consoles, block diagram and circuit diagrams of each part are designed. These are redrawn into OrCAD Capture and using software PSpice simulations are performed. Configuration of the proposed mixing audio console is as follows: Two microphone preamplifiers with true differential inputs with switchable sensitivity, with the quad-band equalizer with tunable mid bands and adjustable delay. One line level input and one instrument input with three bands corrector. The output section consists of headphone and line level out.
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Precise Audio Amplifier for Quality Listening
Janošík, Lukáš ; Šotner, Roman (referee) ; Kratochvíl, Tomáš (advisor)
This bachelor thesis deals with a design of quality audio preamplifier designed for high quality production. The typology of whole design emphasizes very important transmission properties, i.e. high signal-to-noise ratio, high separation of channel, low distortion, The content of the semestral thesis is an symetrical input, relay input switch, 5 band equalizer with bypass and symetrical output with active line driver.
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Integrated multichannel audio amplifier for home cinema
Fišer, Ondřej ; Šotner, Roman (referee) ; Kratochvíl, Tomáš (advisor)
This paper describes complete design of amplifier for home cinema system. Described amplifier has 2 digital inputs (TOSLINK and S/PDIF) and single analog input. With this inputs it is possible to connect amplifier to a source of surround audio 5+1 signal. Paper further discuss design of correction circuits, preamplifier, power amplifier and power source. The whole is controlled by 8-bit microprocessor and has a graphics output implemented through LCD display. The goal of this paper is to design and build high quality amplifier.
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Electronic power-supply for high-pressure lamps
Prachař, Petr ; Kubíček, Michal (referee) ; Šotner, Roman (advisor)
This paper describes the principle functions of high pressure sodium and metal halide lamps. Electronic control circuit involves specific feaures (dimming effect). The proposal is implemented with emphasis on high efficiency and high power factor. An important factor in the proposal is also possibility to connect a many types of high-pressure discharge lamps with different electrical properties. The output inverter operates in resonant mode at high frequency and it is controlled by a microprocessor. It is powered by a bridgeless buck power factor correction.
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