National Repository of Grey Literature 211 records found  beginprevious175 - 184nextend  jump to record: Search took 0.01 seconds. 
Converter with very low input voltage
Jaško, Michal ; Beneš, Petr (referee) ; Havránek, Zdeněk (advisor)
This Bachelor’s thesis describes a design and testing of an increasing direct voltage converter transforming light energy received by a photodiode to electrical energy with sufficient output voltage to power digital circuits. The theoretical part forms an overview of commercial circuits and the Linear Technology LTC3109 and the combination of Seiko S-822Z20 and S-8353D30MC are chosen as suitable for the further research. The function principles of these circuits are described. In the practical part the maximum output power and efficiency dependences on the internal resistance of the power source of the circuits are measured. Based on the results the characteristics of the Linear Technology circuit with different variants of the input transformers are compared. A modified Seiko circuit with an input photodiode is designed and its function is verified by laser diode powering through an optical fiber.
Splicing of special optical fibers
Hlavatý, Václav ; Holík, Milan (referee) ; Mikel, Břetislav (advisor)
The aim of thesis is to design welding processes for special optical fibers. The text describes procedures of modification of the basic welding process for three types of PM fibers. For each fiber type was created specific welding process. All optimized welding processes were tested in terms of reproducibility.
Analysis of optical access networks in the Czech Republic
Štefančík, Matej ; Šifta, Radim (referee) ; Münster, Petr (advisor)
The work provides an introduction to optical access networks. Describes the basic functional units, the architecture of these networks, defines the basic network elements. Discusses various construction technologies from classic to modern. The next chapter analyzes optical access networks in the Czech republic. Focused on actual status of these networks, based on statistical data. An important part is the future direction of development over the next few years. The new trends and ideas that appear in this field. At the end of the chapter was summarized anonymous survey conducted through a questionnaire sent to the owner of the optical access networks, the output of which were the parameters of the networks. All collected data served as a source for design creation of the standard variants of optical access networks along with the technical specifications and financial balances. For individual network designs were developed models in the simulation environment used for the analysis. The last chapter briefly compared strengths and weaknesses of created variants of the optical access networks.
Optical fiber link analysis
Šefara, Petr ; Hudcová, Lucie (referee) ; Poliak, Juraj (advisor)
This theses report on theoretical findings about spreading light in an optical fiber and about causes of origin parasitic effects in optical fiber and their impact on carried signal. There is also explained basic methods of measuring this effects. In this theses is made concept of laboratory measurment of parameters optical link using tutorial set PROMAX EF-970.
Design of Measurement Net
Krajčír, Róbert ; Drexler, Petr (referee) ; Kadlec, Radim (advisor)
This thesis deals with transfer of measured data from sensors placed on pulse power generator for long distances in areas with strong outer interference. Main goal is to design fast and reliable network. Therefore some basic transfer methods, which are available for usage, are analyzed. Regarding to the characteristics of these methods, the most suitable option was chosen, which is analog fiber optic link. In the next phase, the concept of the network itself is dealt with, including analysis and choice from variety of modulation techniques, transmitters and recievers and their characteristics. Variety of drive and amplifier circuits are also mentioned, with emphasis on their influence on transfer and noise attributes and available bandwidth. Based on theoretical analysis and component pros discovered, exact parts are chosen and complete concept of the network is established, including auxiliary circuits. According to this concept printed circuit boards for both transmitter and reciever are made and tested.
Mathematical analysis and simulation of optical fiber transmission parameters
Smrž, Jan ; Šporik, Jan (referee) ; Tejkal, Vladimír (advisor)
This thesis deals with the transmission of optical fibers, their properties and method of calculation. The paper presents different types of fiber types and standards. There is a description of the connection of optical fibers with different methods, including variations joints. Further side effects are broken fibers, dispersion and attenuation. The last part is devoted to describing the program, which was part of this work. The program is used to calculate the transmission parameters of optical fibers and optical losses incurred in connection.
Optical transmission applications in industries
Worbis, Vít ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
The aim of the semestral work term use of optical transmission in the industry is to find the right equipment for communication in industrial applications, which would lead to better control and management of these applications. My show almost seamless connection between the device, which is controlled by another device such as a computer. The first chapter shows how inside the core optical fiber and reflected beams are then carried around the skylight. The second section lists the differences between the copper and fiber cabling, there is described why metallic line slowly destroyed and replaced him fully optics. In the third chapter, I focused on the optical fiber, what are its characteristics, from which parts are made and what is distributed. In the fourth part shows the optical transmitters for multimode and singlemode optical fibers, which are differences between them, which are produced and with what characteristics, etc. In the fifth chapter is applied to a network of possible involvement in the industrial zone, is designed only as they could theoretically be industrial zone controlled by the machine. In the sixth part of the thesis I have tried to design a laboratory task that consists of those optical converters. It is only a small sample, as used in the industry far more extensive involvement.
Measuring unit for analysis of fibre grid properties
Urban, František ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
Thesis focuses on measurement of the properties of the Bragg faber gratings.The method of measurement is based on the spectral scanning by use of the thermal tuning of the laser diode. The optical fiber set for greating evaluation is designed. The thesis contains the design of the electronic control board for laser diodes and photodetectors.
The modulation techniques used in WDM optical networks
Lučenič, Lukáš ; Filka, Miloslav (referee) ; Kočí, Lukáš (advisor)
The main goal of the diploma thesis is DWDM simulation of optical network, defined by recommandation ITU-T. Optical network includes 16 communication channels with length of fiber 50 km. Each channel have to be set with bandwith 50GHz and Bit rate with minimal value 10Gbit/s. The final simulation model includes 8 types of modulation techniques. The result of the thesis is comparison modulation techniques in terms of usability of bandwith and comparison of the quality of transfer
Optical fiber point sensors
Okoun, Petr ; Čučka, Milan (referee) ; Urban, František (advisor)
This diploma thesis analyzes a structure of spot optical sensors with longitudinal grid and multiple Bragg grating and possibilities of spot optical sensors use and implementation in the industry. Basic principles of light propagation through optical environment are described in the introduction part, followed by description of phenomena in optical fibers and sensors. The distribution of fiber optic sensors and the use of optic fiber in spot mode is described further. The optical sensor system is designed on the basis of analysis with description of its construction at the end of this work. A significant part is devoted to the analysis of longitudinal structures in the fiber in response to multiple Bragg gratings, their subsequent manufacture and suggestion of use in sensors industry.

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