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Miniaturized Measurement System for Wind Speed Estimation.
Štěpánek, Michal ; Vágner, Petr (referee) ; Urbanec, Tomáš (advisor)
This thesis is analysis of thermal anemometer, which contains design and realization. For measuring wind speed there are not used any mechanical moving parts in this way. This measuring uses two thermistors. One of these measures temperature of air, which is very important for compensation of whole system. Temperature of second thermistor is kept on constant value. This value is higher than surrounding air temperature about constant difference. Fluctuant air cools this sensor and because of that systém must supply more of heat. By analysis of value of supplied heat, we can calculate the wind speed value.
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Laboratory module of class D amplifier with PWM modulation
Barcík, Peter ; Petržela, Jiří (referee) ; Kratochvíl, Tomáš (advisor)
This bachelor’s thesis describes basic functional blocks of class D audio amplifier. Project also discuss about design of module class D audio amplifier with PWM modulation. As this audio amplifier is going to be a laboratory module, it is necessary to divide design into designs of individual functional blocks. Finally project describes design of output LC filter which is also simulated in PSPICE program. This thesis include complete construction details. Measurement results are shown in standard protocol.
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Design of switching-mode audio power amplifier
Svadbík, Vít ; Sutorý, Tomáš (referee) ; Brančík, Lubomír (advisor)
This work describes the design of audio amplifiers operating in switching mode. The first part describes basic principles of the power stage switching concept. There is described differences between classes of amplifiers according to technology. The second larger part includes design and construction of the switching amplifiers. Design is implemented, including the preamplifier and power supply. Power supply works in switching mode. The measured parameters of the proposed facility are given in the last part.
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DC/AC one-phase inverter 230 V / 50 Hz / 60 VA for a back-up supply source with a galvanic separation
Šoupal, Ondřej ; Procházka, Petr (referee) ; Vorel, Pavel (advisor)
The aim of this thesis is to design power circuits and control circuits of single phase DC/AC inverter and its practical realization. This work describes basic principle of single phase inverter. Next step is a solution of output LC filter, input capacitor and semiconductor devices. It contains block diagram of control circuits and it focuses on design of oscillator for pulse width modulation and current limiting. The thesis gives details about practical realisation and testing measurements. Technical documentation was prepared for this inverter.
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Design and realization of wireless interface ODBII-XBee
Zatloukal, Martin ; Frýza, Tomáš (referee) ; Prokopec, Jan (advisor)
This master’s thesis describes possibilities of usage of ZigBee communication protocol and integrated circuit ELM 327 in problem of realization universal diagnostic device, running by OBDII communication standards, which can be used to monitor function of all car´s electronic systems. Thesis also deals with design and realization of necessary electro technical devices and modules followed by compilation of control software and experimental measurements of these devices in real traffic flow. In the first part of project, there are reminded some basic features and parameters of OBDII, followed by description of ways how to use OBDII and adumbrating how to realize universal diagnostic system. The analysis of ZigBee system focused on XBee circuits follows. Construction, ways of data transfer and possibilities of controlling are described. Integrated circuits produced by ELM Electronics Company are introduced and possibilities of usage ELM 327 are described as requested by main task. Second part talks about designing of electronic circuits of this system, assembling schematic diagram and designing sources for production of PCB. Physical realization of these circuits and its first start is also included. Thesis finishes by dealing with practical experiences and measurements using real vehicles. This part talks also about means to improve system by several software solutions to reach more effective functioning of created device.
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Mikroprocesor control for laboratory power source
Hauer, Petr ; Kubásek, Radek (referee) ; Szabó, Zoltán (advisor)
This bachelor thesis aims to design and implementation a laboratory power supply controlled by microprocessor and PC via USB. The theoretical part describes the USB bus and the manner of its implementation to the microprocessor. There are the basic types of switching and linear sources and methods of control by a microprocessor. The practical part deals with the design and implementation of the resource. The results of this work are the themes of control and power part of power supply, printed circuit boards, software for the PC and microprocessor and measurements on the completed source.
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Adjustable source feeded and controlled by USB bus
Staněk, Miroslav ; Frýza, Tomáš (referee) ; Kolouch, Jaromír (advisor)
The aim of this bachelor’s thesis is concept and realization of voltage source which is controlled and feeded by Universal Serial Bus. There will be presented whole design, execution, development progress and finalization of this project in the following text. This source must boost and buck standard voltage from USB. So it will be necessary using two source lines. Microcontroller of AVR family will be used in the direct part of this adjustable source. Into this microcontroller will be embedded USB interface by the software solution. The microcontroller isn‘t used only for communication with PC by the computer programme, but it is also used for switching the source lines by the PWM modulation. According to the minimum output voltage scale (0 – 15 V) this source is useful for a wide spectrum of low- power devices. This equipment could be helpful together with laptop to charging devices (cell phone, camera, pocket osciloscope etc.), which are carried with notebook for doing outdoor activities and measurements.
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The influence of the frequency converter on the life and damage of bearings
Sukovatý, Adam ; Krejčí, Petr (referee) ; Nahodil, Petr (advisor)
This thesis deals with the effect of frequency inverter on the lifetime of roller bearings. The measurement has been carried out on the frequency inverter and induction motor by Siemens in the Switchgear laboratory of Fakulty of elektrical engineering and communication. Data has been recorded and processed on Adash VA4 Pro analyzer. Methods of measuring RMS values and frequency analysis of vibration and current were used for the analysis. Based on the mutual similarity of frequency spectrum, the presence of the high frequency capacitive current in the bearings has been proven. To prevent this, possible solutions have been presented. In the second part of the experiment an effect of changing pulse width modulation (PWM) on vibration was examined. The goal was to make a basic analysis and to provide background material for further research.
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Audio amplifier with PWM modulation for laboratory measurements
Holub, Josef ; Petržela, Jiří (referee) ; Kratochvíl, Tomáš (advisor)
This paper deals with the theoretical analysis of the essential parts of amplifier operating in Class D. It describes the principles and the relationship between the individual blocks. The second part deals with the design of the block connection of a switched amplifier for a laboratory device. The design part contains calculations, justification of the selection of individual components and integrated circuits and schematic connection within the individual blocks. Some blocks are simulated using PSpice and FilterFree. The work also deals with the structural design of the jig and the creation of a 3D model. The annex is contained overall diagram of an amplifier and a complete reference material for production.
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Class D audio power amplifier for bass guitar
Appel, Daniel ; Petržela, Jiří (referee) ; Brančík, Lubomír (advisor)
The main goal of this project was a synthesis of audio power amplifier and preamplifier for bass guitar with features suitable for this kind of instrument. The project was divided into 6 parts. The first part is a brief introduction to classes of power amplifiers, the second part is about function of blocks of which the class d audio power amplifier consist. In the third part the designed circuits and their properties are discussed. The simulation of circuits in PSICE are also included in this part. The design of power supply unit is discussed in fourth part. In the fifth there is design of chassis and other mechanical constructions. In the sixth part, there are results of experimental measurements of the amplifier prototype. In the appendix of this bachelor thesis are enclosed the schematics, printed circuit board designs, and photographic documentation of amplifier prototype.
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