This thesis is focused on the methodes of crushing kidney’s concrements with continual wave for the frequency 27 kHz and the intensity of ultrasound 10 W/cm2. The main aim is design of the ultrasound head with layer converter and design circuitry. First part of this work describes physical principle of ultrasound, ultrasound waves and methods by which could be remove kidney’s concretions. Practical part of this work is focused on compreshive design of ultrasound crushing system. In the introdiction is analyzed the proposal of applicator and the next step decscribing proposal excitation generator. The work contains results of simulation which was done on proposal curcuit, drawings of scheme, list of components and drawing of PCB.

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.

The work deals with the analysis of time series of diagnostic quantities measured in power oil transformers. The first part includes power oil transformers and the description of diagnostic variables that are measured inside these non-rotating electrical machines. The next section introduces the decomposition model of time series including analysis of all its components. The last part deals with the predictions of the likely survival time of power oil transformers operating in different power plants in the Czech Republic.

This diploma thesis is focused on design of high frequency power amplifiers in UHF band, specifically at 435 MHz. Amplifiers are designed in different classes of operation. The thesis deals with the comparison of main parameters in each class of operation, the most important parameter is effeciency. The amplifying part is unipolar transistor which is working in Single-stage mode. The results were simulated in Advanced Design Systems Software.

This dissertation thesis deals with the application of expert systems and soft computing methods in field of power oil transformers. The main work is divided into theoretical and practical part. First, the theoretical part presents the basic elements of the transformer, and approaches to its diagnosis. The work focused mainly on the diagnostics of the insulation system, and diagnostic methods and approaches in this specific area. Next part describes the basics of expert systems and other soft computing methods such as: fuzzy logic, neural networks, genetic algorithms and their combinations and extensions. At the end of the theoretical part, the possibility of optimization approaches by means of artificial intelligence and its application in fuzzy model optimization are described. The practical part begins with description of the used data file that runs through the entire work. The work is then divided into four parts, namely in parts which deal with the expert system for transformer diagnostics, DGA module, prediction module, and optimization using artificial intelligence. The section describing the expert system gives specific information about the particular expert system. The means and techniques used for constructing given system are described, and then the complete system design and description of all subsystems and modules are presented. The next section describes the developed DGA module and all selected approaches to its implementation and expansion. At the end of the chapter, the results of comparison between all implemented methods are evaluated. The third part deals with the prediction module and describes its design and construction, including description of the main parts which are based on the selected predictive approaches. Also, the predictions of selected quantities from the data file are included. There are two predictive approaches being used: the one step prediction, and the multiple step prediction. The comparison of prediction accuracy and computational cost of given methods is presented at the end of this chapter. The last part deals with the possibilities of optimization using artificial intelligence methods, namely differential evolution, PSO, and genetic algorithms. Both the single-objective and the multi-objective optimization are considered. The methods are compared in a series of synthetic tests and then applied to optimize the fuzzy models of DGA tests from an earlier part of this work. The dissertation also includes chapters: "The Aims", "The Contribution of the Work", and a list of publications, products, and projects of the author.

The thesis is focused on the research and development of a new hybrid one-wire bus with special use enabling microelectronic integration. The bus, its physical layer and protocol have been developed based on applied research to meet the complex requirements of a new application group. These requirements are especially laid on the bus robustness and its immunity to interference and to work under real operating conditions. Part of the thesis is a description of existing solutions of one-wire buses, definition of current solutions and setting of goals for research of the new bus. Further are made the design of protocol and operating parameters of the bus operating in low power and power mode. In conclusion, the thesis deals with the practical verification of the proposed solution and there is also suggested a perspective of follow-up research in this area.

This work deals with a proposal and construction of a DC/DC converter for a control of a DC motor Heinzmann. The DC/DC converter will be used in an electric drive for a bicycle. The proposal of the DC/DC converter is designed for such engine power to avoid fully any human force to drive - pedaling. The work includes informations about the used motor, progress of proposal and dimensioning of the converter - power circuit and control electronics.

This work deals with design, simulation and realisation of a receiving systém of an S-band front end for satellite communication. The first part of the project is designed the low noise amplifier (LNA) with high associated gain. The basic point of the design is choice of the active device. In the present time are available the ultra low noise transistors based on the GaAs with high mobility electron. The two-stage LNA has been designed with Agilent ATF-55143. It is pseudomorphic HEMTs ,which work in an enhancement mode.These transistor do not require a negative bias voltage and have extremely good typical noise figure. The design includes an interdigital tuned band pass filter between stages. The second part of the project is search another way design circuit. There are designed two LNA with paralel coupled line filter. The first has been applied on a PTFE substrate Duroid 5880 with relative permitivity 2,2 and tg d = 0,009. The substrate FR-4 (r = 4.34) with the thickness 0.06” was used for the realization.

Securing of electrical devices is important not only to protect against destruction under the effects of electric current, but also for protection of people or animals against electric shock. With increasing of living standards goes hand in hand increasing of the electricity consumption. Therefore In the grid of low voltage, there are increasing short-circuit currents. With improving technology is posed considerable demand on the performance, security and switching capacity of circuit breakers. This thesis is oriented on development of thermal and electromagnetic switch of circuit breaker on which is put a big demand in development of new types of circuit breakers. The thesis is interesting because of comprehensive use of circuits’ breakers since it can be used in AC and DC networks with frequency of 50 Hz and 400 Hz.

The contents of this thesis is design of audio power amplifier in Class D with fully digital control and remote control and is divided into two parts . The first part is devoted to the basic principles and theory of key elements of the entire amplifier. The second part consists of a complete description of the design and construction of a power amplifier, digital control with remote control, a spectrum analyzer, equalizer, preamp VU meters and complete power supply. Each proposal contains a detailed analysis of the solutions supported by simulations and software. For individual parts have been completely measured p arameters.