The main target of this thesis is to design and realize a prototype of a high capacity battery charger. The charger has been designed as a switching power supply based on a Flyback convertor with two transistors. As switching transistors the integrated circuit IR2110 has been selected. The convertor is controlled by a microcontroller board based on ATMega328 called Arduino Uno; some parts of the Arduino Uno Starter Kit are also used as LCD display, relay and button. In addition, an auxiliary source has been made; this one powers the integration circuit IR2110 and Arduino Uno board. Furthermore, this work introduces us to the processes of charging lithium batteries, types of lithium batteries and methods of charging the lithium iron phosphate (LiFePO4) battery.

The aim of my master’s thesis is the design and implementation of laboratory power supply with output parameters 0-25V and 0-2A and options to manage this resource by elements of the front panel or via a computer control program. Content is the theoretical analysis of the possibility of subsequent theoretical sources suggesting that it verified on the prototype laboratory resources.

This thesis deals with the design and construction of a single-phase switching power supply, which is intended for direct resistive heating of iron components. The power supply is especially intended for resistive heating of horse-shoes. The supply is able to deliver an output current of up to 1500 A at a power of up to 2500 W. The first part of this work deals with the design of individual parts of the unit, the second part is focused on construction and testing of the supply and the last part contains technical documentation. The power supply was successfully tested and the required output parameters were met. However some problems do exist, especially with overheating of the output rectifier and with contacting the heated component to the output leads of the supply. These problems will be discussed in the work. The power supply can be used as an alternative solution to classic means of iron heating. The methods and ideas presented in this work can be applied in a design of a similar power supply with high output current, but most of the design rules are valid generally for the given topology.

The aim of my master’s thesis is the design and implementation of laboratory power supply with output parameters 0-25V and 0-2A and options to manage this resource by elements of the front panel or via a computer control program. Content is the theoretical analysis of the possibility of subsequent theoretical sources suggesting that it verified on the prototype laboratory resources.

Made available in DSpace on 2014-12-17T14:58:04Z (GMT). No. of bitstreams: 1 SaraMFA.pdf: 4966448 bytes, checksum: 1ef74fa9275b2d2eb81d82fd6bcd301f (MD5) Previous issue date: 2010-06-18 / Low voltage solar panels increase the reliability of solar panels due to reduction of in series associations the configurations of photovoltaic cells. The low voltage generation requires DCDC converters devices with high efficiency, enabling raise and regulate the output voltage. This study analyzes the performance of a photovoltaic panel of Solarex, MSX model 77, configured to generate an open circuit voltage of 10.5 V, with load voltage of 8.5 V, with short circuit current of 9 A and a power of 77 W. The solar panel was assembled in the isolated photovoltaic system configuration, with and without energy storage as an interface with a DCDC converter, Booster topology. The converter was designed and fabricated using SMD (Surface Mounted Devices) technology IC (integrated circuit) that regulates its output voltage at 14.2 V, with an efficiency of 87% and providing the load a maximum power of 20.88 W. The system was installed and instrumented for measurement and acquisition of the following data: luminosities, average global radiation (data of INPE Instituto Nacional de Pesquisas Espaciais), solar panel and environment temperatures, solar panel and DC-DC converter output voltages, panel, inverter, and battery charge output currents. The photovoltaic system was initially tested in the laboratory (simulating its functioning in ideal conditions of operation) and then subjected to testing in real field conditions. The panel inclination angle was set at 5.5?, consistent with the latitude of Natal city. Factors such as climatic conditions (simultaneous variations of temperature, solar luminosities and ra diation on the panel), values of load resistance, lower limit of the maximum power required by the load (20.88 W) were predominant factors that panel does not operate with energy efficiency levels greater than 5 to 6%. The average converter efficiency designed in the field test reached 95% / Pain?is solares de baixa tens?o aumentam a confiabilidade dos pain?is solares, devido ? redu??o das associa??es em s?rie nas configura??es das c?lulas fotovoltaicas. A gera??o em baixa tens?o requer dispositivos conversores DC/DC de alto rendimento, que possibilitem elevar e regular a tens?o de sa?da. O presente estudo analisa o desempenho de um painel fotovoltaico da Solarex, modelo MSX 77, configurado para gerar uma tens?o em aberto de 10,5 V, tens?o com carga de 8,5 V, com uma corrente de curto-circuito de 9,0 A, e uma pot?ncia de 77 Watts. O painel solar foi montado na configura??o de sistema fotovoltaico isolado, com e sem armazenamento de energia tendo como elemento de interface um conversor DC-DC, topologia Booster. O conversor foi projetado e confeccionado com circuitos integrados de tecnologia Surface Mounted Devices (SMD), para regular tens?o de sa?da em 14,2V, com rendimento de 87 % , disponibilizando a carga uma pot?ncia m?xima de 20,88W. O sistema foi instalado e instrumentado para medi??o e aquisi??o dos seguintes dados: luminosidades, radia??es m?dias globais (dados do Instituto Nacional de Pesquisas Espaciais (INPE)), temperaturas do painel solar, temperatura ambiente, tens?es de sa?da do painel solar, tens?o de sa?da do conversor DC-DC, correntes de sa?da do painel, do conversor, da carga e da bateria. O conjunto fotovoltaico foi inicialmente ensaiado em laborat?rio (simulando seu funcionamento em condi??es ideais de opera??o) e, em seguida, submetido a testes em condi??es reais de campo. O ?ngulo da inclina??o do painel foi fixado em 5,5?, compat?vel com a latitude da cidade de Natal. Fatores como condi??es clim?ticas (varia??es simult?neas de altas temperaturas e radia??es solares), valores da resist?ncia de carga, baixo limite da m?xima pot?ncia solicitada pela carga (20,88W) foram fatores predominantes para que painel n?o operasse com n?veis de efici?ncia energ?tica maiores que 5 ? 6 %. O rendimento m?dio do conversor projetado nos ensaios de campo alcan?ou 95 %

This master‘s thesis deals with the design of battery powered soldering iron. The soldering iron will be placed in the plastic box from a conventional transformer soldering iron. First, we need to find the parameters of the original transformer soldering iron. Then design a synchronous step-down converter, driver of converter, BMS circuits, and component placement in a plastic box. The battery-powered soldering iron was successfully revived and tested, the final parameters of the converter are: voltage 0.4 V at 80 A current. The total power on the soldering wire is 32 W. Technically, this is a very interesting alternative to the classic version of the soldering iron, which can be used for assembly or repairs in poorly accessible locations.

This thesis focuses on optimization and increasing the efficiency of high-power DC/DC switching converters with transformer (switching power supplies). The work focuses mainly on using converters with flyback topology for high power, even though it is a common belief that this type of converter is not suitable for high power. This topology was selected because of potentially better achievable parameters, especially the efficiency, in comparison to a commonly used forward converter – in a flyback converter, losses are produced only in one magnetic component (transformer) in contrast to two components (transformer and inductor) in the forward converter. Compared to resonant and quasi-resonant converters, the flyback converter is easily controllable in the whole output voltage and current range. To make the flyback converter favorable for a high-power use, some innovative circuit modifications were made and modern semiconductor and passive components were used. Theoretical part of the work deals with efficiency optimization of the flyback converter, based on analytical solution. Operating parameters of the converter – switching frequency and parameters of the transformer (flux density and numbers of turns) are commonly only guessed or chosen from experience. The objective of this part is a mathematically exact determination of these parameters to achieve lowest total losses of the converter for given input parameters. In a certain case, it was possible to obtain the final solution analytically, in other cases the final solution step had to be done with a help of software. A prototype of a 12-kW switching power supply with a flyback converter was constructed to validate the proposed solutions and methods. The power supply fits into a space of only 33x33x16 cm. Modern semiconductors based on the silicon-carbide (SiC) technology (MOS-FET transistors and diodes) were used. After bringing the converter to a full-power operation, an efficiency of 96.8 % of the DC/DC converter was measured. High efficiency was obtained for a wide range of output parameters. A certain comparison with a forward converter with the same output parameters is done in the work. Not only from an efficiency point of view, the flyback converter seems very perspective.

This diploma thesis deals with design of DC/DC converter which will be used in one-phase inverter powered from batteries. Required parameters are output power of 100 W, input voltage of 24 V and output voltage of 350 V. In the first part is briefly discussed used topology of flyback converter. In the next part is designed impulse transformer with a request to design impulse transformer as small as possible. Thesis continues with draft of power components placed on primary and secondary side of converter. In this thesis is part about limitation of voltage overshoot at turn off transistor. Next part of this thesis deals with the design of control circuits using an integrated circuit from the UC384x family. Thesis continues with the production and debugging of the converter. At the end of this thesis are measurements confirming the correctness of the proposed design.

This diploma thesis deals with analysis of function and subsequent construction of a quasi-resonant DC / DC converter 300 V / 50 V for an output of about 1.5 kW. The aim of this work is to test and describe the behavior of an experimental converter at various operating parameters. In the theoretical part, resonant circuits are described, as well as our connection of the resonant converter. Based on the used topology and the simulated behavior of the converter, the individual components of the power circuit and its control and excitation circuit are designed in Chapters 4 and 5. The sixth chapter deals with the construction and testing of the converter, including a description of its behavior. The last chapter contains technical documentation.

This thesis is about theory of switching power supplies and about a specific solution of switching power supply for electron microscope. In the beginning of the thesis are mentioned various solutions of part blocks of switching power supplies, their advanteges and disadvanteges, and their suitability for electron microscopy. In the next part of the thesis are described requirements and design scheme of switching power supply for scanning part of electron microscope. The thesis i also about technical solution and practical testing of the switching power supply and verification of its functions.