Master’s thesis deals with the design concept of DC/DC convertor usable for a backup source with supercapacitors. The paper describes the theoretical knowledge of supercapacitors technology, principle of basic DC/DC convertors and their use in electrical energy storage systems. The thesis contains a description of the designed backup power system and its properties, which has been measured.

In this work a proof of concept for a step-down DC-DC converter used in a high voltage submarine application is presented. The purpose of the converter is to step down a 5000V-6000V input to a 24V output which can serve as an input to a submarine sensor. The completed system consists of two stages where the first stage is an unregulated switched capacitor converter to step down the initial input to a voltage range more appropriate for the selected second stage. The second stage is a regulated flyback converter topology which regulates the final output to the desired 24V. Performance evaluation of the proposed system are carried out using LTspice simulation software. Results of the simulation demonstrate that the proposed converter operates as anticipated with the first stage being able to reduce the initial input by a factor of 16 and the second stage producing a regulated 24V output. Additionally, the proposed converter reaches an efficiency of approximately 74.95% when tested under nominal input and full load conditions. With the same conditions, the converter yields an output voltage ripple of 1.525%, and line and load regulations of 0.0457% and 0.183% respectively.

The aim of this master thesis is to describe the requirements put on electronics and headlights within car industry, above all on the newly emerging 48V power network. In the thesis the principles of chosen DC/DC buck converter topologies are briefly described. In the next part of this thesis the converters are designed and manufactured. Further, the EMC chamber measurement of these converters and their subsequent evaluation is performed. In the last part the proposed converters are compared and evaluated.

This thesis deals with a design of a power supply for a measuring equipment for a geophysical mapping intended to do a reconstruction of an electrical impedance of a ground environment of water reservoirs. The power source is going to be used for laboratory measurements and for outdoor experiments. The thesis describes the selection of suitable components, equipment design and testing. The theoretical part explains the functions of used components and the principle of an electrical impedance tomography. The conclusion summarizes the properties of the proposed solution and evaluates the final product.

This master‘s thesis deals with design and realisation of a control module for automated measurements of the modern contactless inductive position sensors by a mechanical rotational system consisting of a DC motor and an incremental quadrature encoder. The thesis presents methods of driving DC motor and recording of measured data by a microcontroller. The thesis presents a communication protocol between the control module and personal computer via USB interface. A part of this thesis is also to develop a control software and firmware, including the measurement and evaluation of properties of the control module.

Disertační práce je zaměřena na nízkoenergetické konvertory pro zpracování energie. Pro fotovoltaické generátory pracující při nízké úrovní osvětlení byly navrženy konvertory založené na konfiguraci single cell. Pomocí levných výrobních procesů a dostupných materiálů byl navržen a vyroben jednoduchý a spolehlivý termogenerátor. Výrobní postupy využívaly plazmatické aktivace povrchu pomocí výboje s dielektrickou bariérou a modifikované metody depozice PEDOT. Byly navrženy jednoduché a spolehlivé DC/DC měniče pro nízkonapěťové aplikace jako termoelektrické generátory a fotovoltaické články v konfiguraci single cell. Měniče pracují od napětí několika desítek mV a výstupní napětí může být na úrovni několika voltů. Účinnost se blíží 50% a náklady na materiál a výrobu jsou ve srovnání s použitím běžně dostupných integrovaných obvodů pro Energy Harvesting výrazně nižší. Pro řídicí obvody byly použity bipolární tranzistory, které v režimu velmi malých proudů mohou mít napájecí napětí od 0,5 V. Byla ověřena možnost výroby integrovaných obvodů s extrémně nízkým provozním napětím. Tranzistory FET zde pracují v podprahovém režimu a v režimu Bulk-driven.

This master´s thesis is directed to an research of thermoelectric cells as power sources. It is discoursing about general properities of thermoelectric cells and their using at practical aplications in the first part. Then a heating and cooling system is designed and made for a selected type of thermoelectric cell which represents the emergency back-up power source. In the next part a DC/DC step-up converter is designed for a selected type of thermoelectric cell. This converter generates the DC load voltage 12V. The converter is controlled by PWM with a carrier frequency 50kHz.

The master’s thesis is focused on the creation of models of DC/DC converters and control program for input parameters and their configuration. The first part is theoretical and she is dedicated to the description of the program Matlab. The second chapter is dedicated to DC/DC converters. Their function is described there and the necessary equations for the design are derived. All of this is complemented by the calculation of line losses in semiconductor elements and the design of voltage and current regulator. The last two parts deal with the description of the created models in Simulink and control program in a graphical environment. The created program is able to edit and recalculate parameters of the converters, calculate line losses on semiconductor components, perform a model simulation or open it.