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Ultra low noise switching power supply
Raba, Jaroslav ; Leuchter,, Jan (referee) ; Šrámek, Petr (advisor)
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.
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Spin waves in non-trivial magnetic landscapes
Klíma, Jan ; Staňo, Michal (referee) ; Wojewoda, Ondřej (advisor)
Magnonics is a branch of physics dealing with spin waves, or their quanta – magnons. Spin waves are one of the candidates for beyond CMOS technology. Circuits and components utilizing the properties of spin waves have the potential to complement or replace the current technologies based on CMOS chips, which are nearing their physical limit. Information processing via spin waves requires the ability to effectively steer spin waves in magnonic circuits, especially in variously bent waveguides connecting individual circuit elements. Due to spin waves’ anisotropic behaviour, this remains on of the challenges to tackle. In the presented thesis, we used corrugating of the magnetic layer of the waveguides, which induces uniaxial magnetic anisotropy, with which we can control the magnetisation landscape in the waveguide with sub-micrometre precision. Using this approach, we can achieve zero-field-propagation of spin waves in desired modes in arbitrary directions. To aid our designs, we developed a model that analyses energy contributions and calculates the resulting effective magnetic field. Using this model and a thorough analysis of the dispersion relation, we designed a bent magnonic waveguide capable of steering spin waves, which we demonstrated by Brillouin light scattering microscopy.
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Power supply
Matějů, Jan ; Uher, Miroslav (referee) ; Beneš, Petr (advisor)
This work is focused on development of a laboratory power source with low output ripple, its construction and measuring its basic parameters. Basic point of interestion is systems design of a digital controled power source. Document describes problems which has occured and its solutions. Describes designing of a circuit board, its construction and measuring its parameters. Below describes system design, construction and examination of a display and keyboard for operating the device. As a result of this work is realized and measured system design, which achieved relativem low levels of output ripple, short reaction time on change of load, but slower reaction of a current limit. Some parameters has not been entirely fine-tuned, especialy speed of reaction of current limit, amplitude of output distortion volage and stability diring short circuit on output clamps.
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Ultra low noise switching power supply
Raba, Jaroslav ; Leuchter,, Jan (referee) ; Šrámek, Petr (advisor)
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.
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