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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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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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Power-supply generating specified current pulses
Svoboda, Karel ; Petržela, Jiří (referee) ; Šotner, Roman (advisor)
This bachelor’s thesis deals with generation of current impulses, which can be defined in range of few ampers, to resistive load. The first part of this project is focused on analysing of single circuit´s concepts and posibility of theirs analog control. The next part of this work describes whole setup of designed circuit. This thesis includes simulations from PSpice and signal snapshots from an oscilloscope, which prove the functionality and parameters of the whole device. Final section of this work discuss all results achieved during design proces.
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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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Operating Characteristics of LED Sources
Brdečko, Aleš ; Diviš, Daniel (referee) ; Baxant, Petr (advisor)
This semester thesis is dealing with issues of LED (light emiting diod).In the text we can find general summary knowledges about LED, relating their history, construction, principle of working and also treatise about of semiconductor compounds. In thesis are given examples of use indicating their advantages and disadvantages and indicating their parameters. The practical content of this thesis is evaluation of measurement performed on some samples of LED especially graphics addiction of crosses and V-A characteristics measured in addiction on current.
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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 electric distribution network 230V/50Hz. In the first chapter you can find short thesis about electric power supplies. Second chapter contains info about power supplies and their safety and EMC requirements. In the third chapter is analysis of LED. Chapter IV. is dedicated to LED power supply circuit desing and the last chapter is about construction and measuring of parametres of designed power supply.
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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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Optical tweezers for coherence-controlled holographic microscope
Straka, Branislav ; Jákl, Petr (referee) ; Dostál, Zbyněk (advisor)
In the master's thesis, there has been described and explained the principle of operation of the second generation coherence controlled holographic microscope (CCHM2) designed at the Brno University of Technology. There has also been listed theoretical description of the operation of the optical trap, together with the calculation of the forces acting on it, ways of measuring the stiffness of the optical trap and the principle of~creating a time-shared optical traps. The optical tweezers forming a separate module connectable to CCHM2 was designed. Simulation and optimization of parameters of the optical system, mechanical design, manufacturing documentation, current source to power the laser diode which allows to control the diode output power by the controller card connected to the PC was designed. The galvano-optics mirror angle is controlled by the PC card too. The optical tweezer has been designed, manufactured and tested in conjunction with the CCHM2.
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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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