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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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Feedback
Koniar, Martin ; Solčáni, Ján (referee) ; Rathouský, Luděk (advisor)
My diploma work is an installation, made from multiple instances of a device iniciating string resonance via electromagnetic field. These devices along with strings are placed on the wall in geometrical shape. Installation creates loop on multiple levels. Except the fact that installation have a circular shape, position of each string starts at the end of another string. Second, more inconspicious loops takes place in the electromagnetic device resonating the strings, that do that with feedback loop. Strings consist every step of chromatic scale, that repeats itself, just an octave higher. Amplification of the final sound of strings is done purely acoustically, with help of the wall on wich the piece is installed. This piece is in its nature concerned with spirituality in music, not necessarily in sense of evoking a spiritual experience, but rather demonstrating metaphors and parallels, that exists between physical aspects of tonal music and different religious ideas. The symmetrical shape of installation refer to religious and occult visuality, built f.e. in cabal on Fibonacci numbers, that is present not only in nature ( for example, the veins of the leaves grow by these numbers), but also in tonal music system (ancient philosophers were working with this concept, see Plato's Music of the Spheres). Strings in this piece produce drone sound, that is naturally evoking spirituality (most visible in buddhist monk meditation). This sound in the piece demonstrates immutability and constancy, the fact that all the chromatic tones are playing demonstrates wholeness (this fact may produce interesting resonances emerging between chromatic steps), so to speak, the unchangeable laws of physics, or to put it in religious lingo, the god law. The symbol of loop also refers to religion, like the eternal return of the same, the periodicity of history. Strings can be viewed as astrophysical symbol. Everything stated is nothing but my recourse, that should not ultimately determine the perception of the piece by viewer. The goal of the work is to offer experience without need to be put into context
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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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Redesign of Vibration Power Generator with Respect to Overall Volume and Weight
Vaněček, Michal ; Dušek, Daniel (referee) ; Hadaš, Zdeněk (advisor)
This work deals with improvement construction already of the vibration power generator design. The improvement his feature and search ideal construction with reference to material, proportions and power. Gain here mechanical properties, to come to what best tune up and development of new construction for improved check out characteristics as is achievement. Tuning up of correct parameters proceed by the simulation and modelling in ANSYS and MATLAB environment.
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Mutual interaction of pressure pulsations and pulsations of undirect pipe
Hrazdíra, Zdeněk ; Pochylý, František (referee) ; Habán, Vladimír (advisor)
This thesis deals with mathematical modeling of multiphysics FSI (fluid-structure interaction) problem, describing mutual interaction of pressure pulsations and vibrations of indirect pipe in a 2D region. Firstly, physical partial differential equations are derived separately for both media, which are in turn coupled and solved analytically. Results of mentioned models include natural frequency values, amplitude-frequency characteristics and both natural and driven damped oscillations of pipe and liquid.
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Unit for wireless transmission of electrical energy
Jelínek, Aleš ; Kopečný, Lukáš (referee) ; Žalud, Luděk (advisor)
The aim of this work is to prove the practical applicability of the concept of contactless energy transfer using induction coils. The first part deals with the mathematical model and theoretical proof of the concept being able to work in practice and describes the process of detecting resonance of receiver circuit on transmitter side. Next chapter describes hardware solution of the experimental prototype. The last part contains measurement results of a coupling coefficient of coils and discusses performance and notable features of the prototype.
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Oscillatory Power Generator Base on Mechanical Resonant Element
Mihalík, Vlastimil ; Houška, Pavel (referee) ; Hadaš, Zdeněk (advisor)
This work deals with the power supply of wireless sensors. When using a wireless sensor is desirable application of alternative energy sources, because the primary cells or batteries may reduce the extent or length of service of the sensor itself. Ambient energy can be used as a suitable alternative source. This energy must be in an appropriate form, which allows its conversion to electric energy. These appropriate, already used types include: solar en., temperature gradient en., en. of flowing liquids, vibration, etc. The advantage of vibrations is its presence in almost all mechanical systems. One of the possibilities for using the vibration of machine systems for power supply wireless sensors is using the vibration power generator with oscillating component. The generator must be designed so that its resonance frequency coincides with the frequency of vibration in the machine system. This method can be used only if the machinery system vibrations at least partially constant. Another option is to use the vibrations caused by, for example, transit transport, or different step acting factor. In this case, it is desirable that the generator is designed with variable resonant frequency, which can partly be achieved, for example, integrating several oscillating component in the body of generator. After the general analysis of the problem, graduation theses will be concerned with the possibility of use of energy from the short damped oscillation and step impulse. Focusing on a proposal of multi-element structures.
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