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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.

Presented thesis analyses a function of the particular type of the nanopositioner with aim to suggest and construct an electronic device suitable for control of the nanopositioner slider. In presented material there is a description of the control signals and possibility of their generating in the respect of slider movement accuracy. The main goal of the thesis is to describe electronic units ranging from power supply, control processor unit part to end part that directly joint nanopositioner. There is also programme equipment for microcontroller and computer, communication description, movement measuring and calibration and draft for the close-up of the control loop for additional increase of the movement accuracy.

This diplom thesis theoretically deals about principle of pulse welding current source. Work explains operation principle of the single acting transmit converter used in realized construction and mention the others examples of converters types. Goal of the work is design individual parts of source : input filter, pulse transformer, output inductor and power semiconductors components. Thesis also contains description of the regulation circuitry of the converter, auxiliary power supply and pre-driver for power transistors. If everything will be all right prototype of the source will be assembled and measured. Results will be compared with theoretical assumptions.

This thesis is about to introduce the development of switched power supply with output voltage of 5,5 kV and power of 4,3 kW. This thesis directly follows the outputs of two previous semester projects. Main task is about to finish the development of remaining printed circuit boards and perform launching of all parts of developed power supply. Next necessary task is about to assemble a functional prototype of the supply using the developed parts, performing a series of measurement supply’s parameters and creating of technical documentation of mechanical part. There are all stages of supply’s development included in this thesis. From the first part, that describes various types of converters, through the design of all the supply’s parts, to final implementation of functional prototype. There are the results of measurement supply’s parameters at the end of this thesis.

This thesis deals with the issue of switching power supply in terms of noise ratios in the output voltage. In the theoretical part analyzes the basic principle of classical and resonant topology switching power converters in terms of output voltage ripple and switching noise. There are also some possibilities of compensation to minimize switching noise and output ripple. The second part describes the custom design a low noise switching power supply, which is composed of an active power factor corrector, power converters and ripple limiter. The main power converter is designed as an LLC resonant converter. The last part deals with the actual construction of the proposed source, its measurement and presentation of the results.