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Driver of Semiconductor laser for 1Gbit/s
Melichárek, Radek ; Vařacha, František (referee) ; Prokeš, Aleš (advisor)
This thesis describes a design of a driver for a specific type of laser VCSEL. Models for simulation in PSpice OrCAD have been developed for this type of laser. The qualities of the designed driver aim to be equal to the integrated drivers that are available and to remove some of their drawbacks. It consists of the following components: input LVPECL receiver/driver, differential amplifier, fixed source of a modulation current, circuit of automatic power control. Regulation of the modulation current is dealt with atypically using an aptly selected input LVPECL receiver/driver which enables to control the voltage amplitude on its output by means of voltage. The thesis also describes different types of coupling between laser and driver. The most appropriate alternative is selected taking into consideration the unconventional design of the driver. The connection of the driver is supplemented by a microcontroller which secures control of output optical power by means of a serial bus RS232.
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Driver of high brightness white LED
Tomášek, Petr ; Kubíček, Michal (referee) ; Frýza, Tomáš (advisor)
This document is analysing LED driving with switch power supply from classic electric network 230V/50Hz. First chapter analysis LED diodes function and its fundamental parameters . In the second chapter, there is essential information about electric power supply. Third chapter is analysing switch power supply, including simple techniques, which are not used nowadays. In the fourth chapter, there is analysis of LED driver and circuit design. Fifth chapter is analysing construction of driver and its safety. There i salso information about measuring of parameters of constructed driver.
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Utilization of light emitting diode lighting
Podola, David ; Černý, Michal (referee) ; Paloušek, David (advisor)
This bachelor thesis deals with problems of illumination by LED diodes. Basic concepts of lighting technology are defined in the first part. The second part is dealing with the construction of body LED diodes and explains the principle of white light formation to LED. Introduces problems of cooling. Gives an overview of the available power sources for LEDs. Provides an overview of how to control lighting by using motion sensors and presence sensors. Will be made basic economic balance sheet, which will evaluate the advantages of using LED sources. Attachments provide the LED catalogs of manufacturers, accessories for LED and comment on other sources of information.
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Current source for the switchgear thermal test
Košíček, Jiří ; Huták, Petr (referee) ; Patočka, Miroslav (advisor)
This thesis describes the design of semiconductor source for laboratory measurements of switchgears. The proposed source is able to use 16-250Hz frequency, fulfilling the standard value of voltage and current distortion. There are explained the theoretical knowledge of various types of inverters without transformer in the thesis. Furthermore, a circumferential proposal of source is made, which includes calculating the desired properties of individual components, their choice from offers from various manufacturers, and subsequently is constructed the total design solution. It is described the control and management of designed source and it is evaluated for the function finally.
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Controlled light source
Pazderský, Tomáš ; Macků, Robert (referee) ; Škarvada, Pavel (advisor)
The aim of the Master´s thesis is proposing and implementation of computer controlled optical radiation source. The theoretical part describes the photometric, the radiometric quantities, applied components such as LED, the microcontroller and possible methods for the LED brightness control. The development of the device is described from the selection of the individual LEDs to the end of the device assembling and programing. On the several LEDs were made properties measurement. A circuit with microcontroller was designed and then was fabricated. The device was programmed for communication and control from the PC. The entire electronic is fitted in the metal frame of the construction box and finally the device functionality is tested.
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USB battery tester
Andrysík, Lukáš ; Langhammer, Lukáš (referee) ; Lattenberg, Ivo (advisor)
This bachelor's thesis contains construction of battery tester along with primary and secondary cells comparsion. It consists of four parts - the first one focuses on general description of the most commonly used electrochemical cells, their characteristics, advantages and disadvantages. Second one relates to design a custom equipment for testing these cells including software, parts values calculations and common problems with the design. Third part is mainly about mechanical design and PCB manufacture. The last section is devoted to comparsion of several models of cells in terms of capacity and performance under different conditions.
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Laboratory Measurements of Skin Conductance
Slouka, Petr ; Harabiš, Vratislav (referee) ; Sekora, Jiří (advisor)
This thesis contains an introduction to anatomy and physiology of the skin highlighting its barrier function. The barrier function of the skin enables it to separate internal organism from external environment. thermore, the electrical properties of the skin are described and possibilities of skin conductance measurement are discussed. The thesis presents a design of a device for the skin conductance measurement as the method of evaluation for barrier function. Alternating current is used for measurement during iontophoresis for evaluation of skin conductance. Circuit design and circuit board are included with a list of parts. The designed device was realized and in the end it was tested and the results were discussed.
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Draft sources 1000A AC current sensors for calibration
Klimeš, Jan ; Vetiška, Vojtěch (referee) ; Dohnal, Petr (advisor)
This bachelor thesis deals with design and construction of device for precise measurement of 1000 A alternate current. This thesis theoretically discusses the possibilities of conventional solutions, such as current transformers, as well as modern methods in the form of current sensors. The output of this thesis is a solution of problems with accuracy and discussion of other possible ways to reduce systematic error. The thesis discusses structure of the current transformer, the digitalizing of the signal and its usage as an input for engineering units. The device is then tested for final accuracy.
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Static and dynamic properties of current sources
Čech, Vojtěch ; Boušek, Jaroslav (referee) ; Horák, Michal (advisor)
The goal of this thesis is to describe the main attributes of current sources and their use as current mirrors. It is focused on the most common variations, and is specially targeted the principles and features of the Wilson-current-mirror, which is composed of bipolar and unipolar transistors. The goal is to compare them, on the basis of the analysis.
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LED Driver evaluation kit for Automotive Front-Lighting
Večeřa, Jindřich ; Kubíček, Michal (referee) ; Dřínovský, Jiří (advisor)
This thesis deals with design of evaluation platform for integrated circuit NCV78934, which is designed to control LED headlights in automotive industry. The theory concerning the current regulation of buck converter, schematic design, PCB design and software design are also included in the thesis. Finally the measured data and testing procedures of the designed evaluation platform are discussed.
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