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Class D audio amplifier for laboratory measurements
Svorad, Adam ; Petržela, Jiří (referee) ; Kratochvíl, Tomáš (advisor)
Bachelor’s thesis delves into a field of Class-D audio amplifiers. Keystone part of the work summarizes theoretical knowledge focused on measuring techniques of lowfrequency amplifiers and audio amplifier design. A deeper insight into building blocks of a general Class-D amplifier is also presented. Gained erudition is applied in the second part, which is devoted to a construction of the device. Exceptional attention is drawn to the design of robust external driver and sophisticated output analog filter. Blueprints required for a PBC layout are provided as well as outputs of performance measurements taken of a fabricated prototype.
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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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Unconventional Signals Oscillators
Hruboš, Zdeněk ; Galajda, Pavol (referee) ; Štork, Milan (referee) ; Petržela, Jiří (advisor)
Dizertační práce se zabývá elektronicky nastavitelnými oscilátory, studiem nelineárních vlastností spojených s použitými aktivními prvky a posouzením možnosti vzniku chaotického signálu v harmonických oscilátorech. Jednotlivé příklady vzniku podivných atraktorů jsou detailně diskutovány. V doktorské práci je dále prezentováno modelování reálných fyzikálních a biologických systémů vykazujících chaotické chování pomocí analogových elektronických obvodů a moderních aktivních prvků (OTA, MO-OTA, CCII ±, DVCC ±, atd.), včetně experimentálního ověření navržených struktur. Další část práce se zabývá možnostmi v oblasti analogově – digitální syntézy nelineárních dynamických systémů, studiem změny matematických modelů a odpovídajícím řešením. Na závěr je uvedena analýza vlivu a dopadu parazitních vlastností aktivních prvků z hlediska kvalitativních změn v globálním dynamickém chování jednotlivých systémů s možností zániku chaosu v důsledku parazitních vlastností použitých aktivních prvků.
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Laboratory Switching Power Supply
Slezák, Jakub ; Petržela, Jiří (referee) ; Šebesta, Jiří (advisor)
This bachelor’s thesis is concerned with design switching power supply based on forward converter with output voltage regulated in the range of 3 to 30V and load current to 1 A. First of all, it discusses the theoretical solution of basic types of converters and switching power supply problems. Followed by a proposal of various parts source, which was first established in the test version on the test board. Then was proposed printed circuit board and complete mechanical solutions. Source is also equipped with digital modules for measuring voltage and current, and is protected against overload.
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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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Complete design of three-way speakers
Jalový, Michal ; Petržela, Jiří (referee) ; Slezák, Josef (advisor)
This project describes complete design of Three-way speakers. The introduction discussed the basic theoretical knowledge to the understanding of loudspeaker system design issues with regard to the physiology of hearing, the theory of acoustics, speaker characteristics, types of enclosures and the use of switches. Furthermore, based on the formula calculated parameters of a loudspeaker cabinet and speaker points to the loudspeaker of the proposed speakers.The proposal also relies on the specific measurement properties of the selected speaker impedance. Finally all data are presented for practical implementation speakers.
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Voltage and current integrators based on modern functional blocks and their application in filters
Šimůnek, Martin ; Petržela, Jiří (referee) ; Dostál, Tomáš (advisor)
The aim of this bachelor´s thesis was utilization of current integrator and voltage integrator along with construction of active filters. In this project are discribed universal filters, which were proposed on the basis of signal flow graphs. In this paper are presented five multifunctional sixth-order filters, which are used in modern functional blocks, for example operational amplifiers (OPA), transconductors (OTA) and current conveyors (CCII+,CCII-). From the mentioned operation amplifiers and the well-known capacitor are created integrators, which the multifunctional sixth-order filter is designed from based on cascade sorting. The aim of this paper is to compare particular types of suggested solutions and to verify the possibility of practical use of these filters with following simulations.
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Driven chaotic oscillators
Pšeno, Daniel ; Guzan,, Milan (referee) ; Petržela, Jiří (advisor)
The theme of this masters thesis are driven chaotic oscillators. The aim of this project is show the various types of driven chaotic oscillator and propose mathematical model solutions using numerical methods. In the first part of this thesis are shown theory of chaos, history of chaos theory, chaotic systems and chaos quantifiers. Next is numerical analysis of differential equations second order by Runge-Kutta fourth order method. Next part contains circuit blocks and synthesis of oscillators. In next part are defined all types of oscillators. Parameters of analysis, equations, circuits and simulations are defined for each type of driven chaotic oscillators. In each subchapter is design electrical circuit. This circuit is simulated and some of them realized.
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Active controllable frequency filter in current mode
Zbořil, Jan ; Petržela, Jiří (referee) ; Brančík, Lubomír (advisor)
The aiml of this work is to study the principles controllable frequency filters in the current mode. Is realized multifuctional current filter. Summarizes the general characteristic of the current components. Work focuses mainly on current conveyors CCII. Circuit is used here EL 2082 as a basic building element. The second chapter discussed the characteristics of filters, the third contains a description of the basic active circuit. The next chapter deals with the simulation, and the last presents the measured results.
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