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Switching loss reduction in the switch-mode supplies
Vašíček, Adam ; Vorel, Pavel (referee) ; Patočka, Miroslav (advisor)
The master's thesis covers in its first parts origins and consequnces of the switching losses, basic principles of the various resonant tanks and resonant DC/DC converters. Afterwards the innovative approach of the multiperiod modulation is presented. The main advantages of this kind of modulation include very wide zero current switching region and lowering the switching frequency as the output voltage decreases. In the remaining part of the thesis a prototype converter design is described.
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Electronic power-supply for high-pressure lamps
Prachař, Petr ; Kubíček, Michal (referee) ; Šotner, Roman (advisor)
This paper describes the principle functions of high pressure sodium and metal halide lamps. Electronic control circuit involves specific feaures (dimming effect). The proposal is implemented with emphasis on high efficiency and high power factor. An important factor in the proposal is also possibility to connect a many types of high-pressure discharge lamps with different electrical properties. The output inverter operates in resonant mode at high frequency and it is controlled by a microprocessor. It is powered by a bridgeless buck power factor correction.
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Back-up power supply 230V/50Hz/300VA with a battery supply 12V
Snítilý, David ; Patočka, Miroslav (referee) ; Vorel, Pavel (advisor)
The aim of this project is to describe, design and create a converter from 12V DC to 230 VRMS. The power of this device is about 500W. The device consists of two main converters. The first one is step-up DC/DC converter and the other is DC/AC inverter. Step-up converter is designed as a resonant converter. It is useful for pushing down losses in semiconductors and inceasing efficiency. The inverter is changing DC voltage from the first converter to AC voltage. Control of this device is realized with DSP Motorola. This device should be used mainly for supply common devices up to 500W. Main usage is planed in a car or to another place where is not posible to connect some device to plug.
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Resonant and quasi-resonant converters
Krška, Vlastimil ; Sedláček, Jiří (referee) ; Murina, Milan (advisor)
Project is engaged in concept and realization of quasi – resonant converter with switching in minimum voltage which derive benefit from resonance capacitor and inductor. It is one of the possibilities how to increase efficiency of switch – mode power supply. While using resonant converters the losses are reduced, when the resonant inductor will connect and disconnect at zero current in inductor, or at zero voltage on inductor. Base of the power supply is chip NCP1337. Concept comes from detailed analysis functions of integrated curcuit and others curcuits of switch – mode power supply. Project includes a complete concept of all partial curcuits, description of a construction and the main parameters measured on the realized sample.
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Wireless power transfer 20 kW
Tománek, Radek ; Vorel, Pavel (referee) ; Martiš, Jan (advisor)
This thesis deals with the design of wireless power transfer at a distance of 600 mm dimensioned to 20 kW. The transfer is provided by inductive coupling of resonant circuits with 800 mm diameter coils. It contains a description of the design and calculations of individual parts, stating specific values. It also includes description and schematics of control circuits.
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DC/DC converter for car-audio amplifier
Šmarda, Vladislav ; Vorel, Pavel (referee) ; Červinka, Dalibor (advisor)
This Bachelor thesis deals with the design and construction of a resonant switching power supply for car audio-amplifier. The main subject of the theoretical part is the mathematical description of the applied ZVCS Push-Push topology. Also a general guide, for designing this type of topology is mentioned. There is described the optimalization procedure of the main switch mode power transformer with respect to the high efficiency of the proposed power supply. Then the designed power supply is made and tested.
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Switch-Mode Power Suplies for Electronic Circuits
Hantl, Josef ; Steinbauer, Miloslav (referee) ; Murina, Milan (advisor)
This bachelor’s thesis deals problems with Switching Power supplies and their comparison with classical power supplies. In this project, functions of basic kinds of convertors for Switchmode supplies and their characteristics, are explained. It adverts to possibilities improving of effectivity of power supplies by using resonant and quasiresonant convertors in switching supplies. The thesis designs a circuit conception, detailed perimeter design of Switchmode supply and contains simulation this circuitry. One part of this project are details for realisation power supply (drawing printed circuit, list of used materials).
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Oscilloscope supply source with a low parasitic capacity of the galvanic separation
Tauš, Michal ; Martiš, Jan (referee) ; Vorel, Pavel (advisor)
This thesis deals with design of a DC/DC converter for powering the oscilloscope. The main parameters for selecting a suitable inverter are: galvanic isolation of input and output parts of the inverter and low parasitic capacitance of galvanic isolation. The required power of the inverter is 100 W and the output voltage is 325 V. The introduction briefly explains why the DC/DC converter with transformer will be used. The first part of the work deals with the selection of a suitable types of DC/DC converter with transformer for powering the oscilloscope. The next part is devoted to designing of the power parts of resonant converter and single acting flyback converter. This is followed by a complete design of a single-acting flyback converter, including the realization and measurement of the time courses of important quantities.
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Medium Power LCC Resonant Converter
Petrásek, Radek ; Dřínovský, Jiří (referee) ; Šebesta, Jiří (advisor)
The aim of this diploma thesis is to study the resonant converters operation. This paper is concretely specialized to design and implementation the LLC resonant converter with output power about 350 watts. LLC resonant converter is prospective solution for similar applications. The general advantages are that the power MOSFETs are working on zero voltage switching condition, which reduce the switching loss and improve EMI performance. The detailed design for the LLC resonant tank characteristics presented in this paper, which fully guarantees the ZVS condition. This study is based on replacing the rectifier and load by an equivalent resistance applies the first harmonics approximation and the assumption that the current trough the diodes of the output rectifier has a sinusoidal waveform.
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