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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Měření rozložení optické intenzity ve vzdálené zóně / Measurement of the optical intensity distribution at the far field

Vitásek, Jan January 2009 (has links)
The topic of this master’s thesis is energy measurement of the optical intensity distribu-tion at the far field. Properties of the optical intensity and the optical power are described. In this thesis solution of wave equation is done. The plane wave, spherical wave and Gaussian beam are described. In this thesis, optical trace of laser beam from transmitter laser diode to receiver PIN photodiode is described. One of the solved problems is diffraction on the lens socket. The basic configuration for diffraction investigation on lens socket was created. There were transmitting laser diode, stop with circular apertures and PIN photodiode used in the experiment. In the other part, thesis deals with measuring and detection of the optical beam. Sorts of photodiodes and their characteristics were analysed.
2

Řízení laserových diod s využitím mikrokontroléru AVR / Laser diodes controller utilizing AVR microcontroller

Boštík, Jiří January 2017 (has links)
This thesis deals with the design and subsequent realization of laser diode control devices. The circuit will be able to control the diode with using a laser driver, via a computer network or via the display for control current values, setting of initial values and more. The device will be connected also with a SD card for saving of settings. In the theoretical part there are described individual components that are needed for functionality of the device. The practical part contains a block diagram, in which is described complete feature of the device, then a draft scheme with a description of all integrated circuits and important components. At the end of this work is described the software that controls the entire designed device.
3

Regulovatelný zdroj pro napájení LED / Controllable power supply for LED lighting

Morávek, Petr January 2018 (has links)
This thesis deals with the description of artificial light sources, that use light-emitting diodes for their operation. Further down, the parameters of LEDs and their emissions are detailed. The work follows with the characterization of principles of LED power regulation. In the practical section, an example of one of the possible LED light source topologies, is designed. The offered solution includes the options to manually and automatically regulate the chromaticity of emitted light. Functionality of the solution was verified experimentally.
4

Teplotní vlastnosti automobilových zdrojů světla - LED / Thermal properties of automotive light sources - LED

Bárta, Jiří January 2018 (has links)
The aim of this theses is to summarize the basic information about thermal properties of automobile lighting sources. The main topic is a LED diode. A model of a LED diode is going to be created in Inventor. A simulation of Joule's losses will be performed in Ansys Workbench Transient.
5

Bezkontaktní měření otáček ventilátoru / Contactless measuring ventilator-revolution counter

Pokorný, Aleš January 2010 (has links)
This project is about design of contactless measuring ventilator - revolution counter. The counter serves to measurement of the speed of ventilator. The measurement is based on optical method of receiving the reflected laser beam. To measure and calculate use the revolution counter the microcontroller. This measured value is diplayed on LCD. After design follows experimental measurement.
6

Rekonfigurovatelná flíčková anténa / Reconfigurable patch antenna

Zlatníček, Radek January 2011 (has links)
The master's thesis deals with the design and implementation of a reconfigurable patch antenna. The antenna is fed by a microstrip transmission line. To the microstrip feeder, tuning stubs are connected. Each stub matches the input impedance of the antenna to 50 ? for different operation frequencies. Stubs can be individually connected to the feeder by PIN diodes; operation frequency of the antenna can be switched that way. In the project, the antenna is initially designed for antenna substrate RO3006. Then, the design will be converted to the substrate ARLON AD600 selected for the realization. In the project, modifications of stubs will be proposed to properly connect the PIN diodes. Functionality of the designed antenna will be verified by modeling in Ansoft Designer. The last part will be dealt with implementation of the antenna and the experimental measurement of their properties.
7

Osvětlovací soustava pro konfokální mikroskop s duálním rastrováním / Illuminating system for a tandem-scanning confocal microscope

Slabý, Tomáš January 2008 (has links)
The diploma thesis deals with a design of illuminating system for tandem-scanning confocal microscope using a high-power LEDs.
8

Zpětné zotavení ve výkonových integrovaných obvodech / Reverse recovery in power integrated circuits

Šuľan, Dušan January 2016 (has links)
Předkládaná práce se zabývá parametrem “Reverse Recovery Time“ u polovodičových prvků a jeho vlivem na typické spínací obvody. V první části práce je objasněno co je “Reverse Recovery Time“ a jeho jednotlivé části. V další sekci je popsána jeho fyzikální podstata. Na konci teoretická části je rozebrán jeho efekt na spínací ztráty a doporučená metoda měření tohto parametru . Praktická část práce je zaměřena na simulace Dpdr45nres45 v prostředích Cadence a TCAD. Poslední část se zabývá návrhem obvodu na měření u reálných diod a samotným měřením diod a tranzistorů.
9

Magnetická pole pro biomedicínské experimenty / Magnetic fields for biomedical experiments

Otýpka, Jan January 2010 (has links)
In this work deals with magnetic fields for use in biomedicine. This solution involves the choice of the correct geometric arrangement of coils for generating magnetic field with a homogeneous distribution of magnetic induction of the widest possible area. The paper compares thre traditional types of coils, solenoid, toroid and Helmholtz coil. For Helmholtz and solenoid coil and is then carried out an analysis of the magnetic flux density in the inner space. Next part is devoted to electrical resonance in the LC circuit. This is then utilized for the development of pulsed magnetic field in the Helmholtz coil. It summarizes the theoretical and practical knowledge to design and construction of resonant converters. The end is devoted to the measurement of circuit parameters and verification of theoretical knowledge.
10

Výkonové ztráty v optické části spoje pracujícího ve volném prostoru / Power losses in optical part of the link working in free space

Szajkó, Juraj January 2011 (has links)
Tato diplomová práce pojednává o charakteristikách laserových diod, difrakcí a o vlastnostech gausovského svazku. Je určen útlum vazby vysílací dioda - vysílací apertura v závislosti na velikostech apertury a na velikosti svazku v programu MATLAB. Jsou stanoveny optimální parametry vazby apertura-dioda.

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