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Portable source for induction heating
Nevřela, Tomáš ; Martiš, Jan (referee) ; Knobloch, Jan (advisor)
The aim of this work is to realize and test a prototype portable source for induction heating of small parts. The project contains a theoretical basis of resonant circuits and induction heating. The device design is based on simulation results from the FEMM program, with which a focussing coil for induction heating has been designed. The parts of the thesis are the realization of the designed device, its putting into operation and the programming of the control.
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Indikator position behind the wall
Pecha, Václav ; Marcoň, Petr (referee) ; Szabó, Zoltán (advisor)
The work sums up the basic measurement principles for different kinds of searching devises. It deals with measurement using resonance. The feature of resonance and measurement techniques are described to set the location of the radiating circuite. The work contains the design of a locator of position behind a wall itself as well as the concrete switch connection, schema and description of receiver and emitter in the circuit.
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Design of a technological structure with use of BIM methodology
Brodecká, Denisa ; Bukovská, Pavla (referee) ; Vild, Martin (advisor)
Diploma thesis deals with the design of load-bearing steel structure for hot vapor air cooler. Part of this diploma thesis is also modal analysis of the construction and subsequent inspection of eigenmodes for eigen frequencies close to frequencies of the ventilator, to assess the resonance. The thesis contains of the design and check of structure elements in the computational software, including hand-done static calculation of chosen elements. Five joints are solved using Idea Statica and five hand-done checks of sub-connections, including design and solution of foundation pad. Next part of the outcome of this thesis is creation of digital construction model, including drawings. The Tekla Structures software was used to create DiMS.
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Wideband planar antenna
Večerka, Kamil ; Lukeš, Zbyněk (referee) ; Raida, Zbyněk (advisor)
In this semester work is analyzed broadband planar antennas published in foreign literature, which represents the current trend of planar antennas. It describes the overall design of the antenna including a description and enter your own simulation program Ansoft Designer, comparing simulations for various types of additional resonators and their influence on the resulting frequency characteristics.
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Solid State Tesla Coil
Pařenica, Jakub ; Mikláš, Ján (referee) ; Martiš, Jan (advisor)
The bachelor's thesis focuses on a theoretical description of the operation of Tesla's transformer, its design, including electronics, and its subsequent construction. The basic theory of the transformer replacement scheme is described. The Tesla transformer is generally described, as well as the methods of excitation of the primary side of the transformer, the generation of the discharge, the skin effect and the meaning of resonance. Furthermore, the work describes the construction of the primary coil holder, secondary coil. The work contains a pattern of the power board from the Eagle program, and everything is accompanied by photos. The work describes the recovery procedure and describes all the waveforms that were measured before and after the connection of the secondary coil.
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Mutual interaction of pressure pulsations and pipe vibration
Hrazdíra, Zdeněk ; Fialová, Simona (referee) ; Habán, Vladimír (advisor)
The aim of this thesis is to find out the effects of pipe vibrations on pressure pulsations in liquids. The pipe-liquid system is mathematically described by proper boundary conditions and wave equations, which are derived from basic physical laws. Firstly, simplified model of only liquid is considered, which is then compared to the results obtained from analysis of pipe-liquid mutual interaction.
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Switched Mode Power Supplies
Španěl, Petr ; Lettl,, Jiří (referee) ; Kadaník,, Petr (referee) ; Procházka, Petr (advisor)
This thesis deals with switched mode power supplies based on resonant principle to achieve high efficiency. Several ways of switched mode power supplies optimalisation are described as part of the work to achieve better efficiency. Priparily, the new generation of switching elements based on SiC and resonant topology are used to achieve significant switching loss minimization. The selected resonant topology is simualted in detail and then built with focus on high efficiency. The main content of the work consists in the design and realization of the switched mode power supply with selected control algorithms and their comparison. The problems associated with usage of new SiC MOSFET generation in TO-247-4L package are being solved within the design and implementation of the power source. To solve the main problems, new 3rd SiC MOSFET gate driver was developer for working with switching frequencies in hundreds of kHz and resisting very high voltage stress on the controlled transistor. The next part of the gate driver is the overcurrent protection. The overcurrent limit can be set easily by changing one component. This protection reacts very quickly in hundreds of nanoseconds, so it is capable of saving the converter even in branch failure and going to hard short circuit. The functional sample of the series resonant converter was built and revated in the work. The converter based on 3. Generation of SiC MOSFET transistors from Cree in a modern case TO-247-4L was built. For this inverter, it was also necessary to develop both the control scheme and the resonance frequency tracking to achieve accurate switching and thus achieve the use of the resonant principle of the converter to the maximum extent possible. The result of this work is up to 3 kW converter with adjustable output voltage while maintaining high efficiency up to 96%.
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Self-excited and forced pulsations of liquid in axisymmetric domain
Skopalová, Kristýna ; Habán, Vladimír (referee) ; Pochylý, František (advisor)
The diploma thesis deals with the determination of the self-excited and forced pulsation of the real fluid in the cylindrical area and in the annulus. It also focuses on a case of resonance that has an unfavorable effect on the hydraulic circuit. The result of the thesis is the analytical relations for determination of self-excited and forced shapes of flow and pressure in the closed cylindrical area, for two selected variants of kinematic excitation. In the first variant, excitation is performed in the form of a sinus function. The second variant is expressed as a sawtooth function. A pulsation of the fluid caused by the movement of the body is described for the annulus. Further, in this area, the shapes of fluid pulsation are solved without external excitation.
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