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Design of a measurement circuit for electrochemical cells cycling in SEM chamber
Tran, Quoc Bao ; Trochta, David (referee) ; Klvač, Ondřej (advisor)
This diploma thesis deals with the design of a measurement circuit consisting of two separate modules for measuring electric current in the order of nanoamperes (nA) for the in-situ analysis of lithium-ion cells in microscopic dimensions. The aim of this thesis is to build a prototype measurement circuit to solve the electromagnetic interference (EMI) problems associated with in-situ analysis and to perform subsequent testing of this circuit or modules. The diploma thesis is divided into two parts, namely a theoretical and an experimental part. In the theoretical part, research on electrochemical cells is described, where the focus is directed towards lithium-ion cells. The principle of the function of these cells is described and research on their degradation mechanisms has also been carried out. Furthermore, the testing methods of lithium-ion cells such as GCPL, OCV and CV have been described. In the theoretical part, the in-situ experiments already performed at Thermo Fisher Scientific Brno are described. One experiment consisted of assembling an electrochemical cell on a MEMS chip and the other experiment was performed using a micromanipulator as a current collector. Measured data were affected by electromagnetic interference. The practical part discusses the design of a measurement circuit that would theoretically solve the problems of measuring very small currents from an EMI perspective. It also describes how the measurement circuit was tested.
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Design and realization of an optical receiver module for VLC purposes.
Grygar, Josef ; Vitásek, Jan (referee) ; Dobesch, Aleš (advisor)
This work is focused on free space optical communication in visible electromagnetic spectrum known as visible light communication (VLC). Basic parameters of standard IEEE 802.15.7, advantages and disadvantages are discussed in the theoretical part of this work. Furthermore, optical link and it´s parts are described. The largest part of the work is focused on design and simulation of optical receiver for visible spectrum. Selection of component, noise and SNR calculation is discussed as well. This work also includes calculation of power energy in different parts of optical connection, PCB design of optical receiver, transmitters and power supply and output board. Behavior and parameters of electronic circuits, components and optical connection are explored, measured and compared with theoretical values.
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Wideband transimpedance photodiode amplifier
Šťastný, Martin ; Roubal, Zdeněk (referee) ; Drexler, Petr (advisor)
This thesis deals with the design of transimpedance amplifier with high gain. There are described different principles of semiconductor sensors of optical signal. There is also a comparison of different methods of converting the photocurrent to voltage. It also discusses the design of an appropriate feedback capacitor in terms of stability in participation as a transimpedance amplifier. It examines the impact of non-zero currents flowing to the input operational amplifier circuit functionality and output offset compensation. Part of the thesis is a simulation that confirms the calculated values. The thesis also deals with the implementation of the receiver and the method of correct measurement of the cut-off frequency.
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Detector of optical beam position
Lukáč, Vladimír ; Barcík, Peter (referee) ; Kolka, Zdeněk (advisor)
The bachelor's thesis deals with the design of an optical beam position detector with the required parameters. The aim was to select a suitable photodetector that captures light rays and converts them into photocurrent, to design photocurrent processing into a voltage signal with linear properties and specified parameters, to convert the analog form of the voltage signal into digital information with which a microcomputer or microcontroller can work. The analog part of the work is simulated in the program OrCAD PSpice, in which the functionality and correctness of the designs is confirmed. The digital part processes the voltage signal to the information of the used channel, its level displays this data on the display.
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Design of EMC optical converter
Štěpánek, Adam ; Hruboš, Zdeněk (referee) ; Krutílek, David (advisor)
Master's thesis is focused on designing optical converter for EMC measurement transfering signal through noisy enviroment. First part contains analysis of electromagnetic interference and its coupling and measurement, especially types of probes for interference maesurement. Next part passing through designing of optoelectric and electrooptic converter with digital intensity modulation. Last part is about realization of optical converter.
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Module for detection of ionizing radiation
Matějka, Tomáš ; Džbánek, Lukáš (referee) ; Kubíček, Michal (advisor)
This thesis deals with design of detector of ionizing X-ray radiation. Conventional PIN photodiodes are used for construction of the detector. The thesis describes issue of using PIN photodiodes for X-ray and gamma radiation detection. Transimpedance amplifier is designed with two diferent modes of detection. Both amplifier variants are compared and their suitability for specific applications is discussed. The thesis describes principle of converting analog signals to digital and describes concept of bus for multiple detectors connection to central unit. Options for paralel data processing are discused in last part of thesis. The detector is implemented and measured values are compared with simulations.
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Photoreceivers with modern integrated circuits
Matyáš, Petr ; Murina, Milan (referee) ; Drexler, Petr (advisor)
The main goal of the bachelors project is to find the proper device to design a receiver of the anologue modulated optical signal. The only condition is to use the device, which is able to output the signal of 100 MHz bandwidth. The theoretical part concerned on description of main types of a photodiode and its basic features, its advantages and disadvantages. Different circuit applications of photodiode are presented. The main advantages of using operational amplifiers in those circuits are shown. In the next part of the project a few types of circuit connections of photodiode are presented. The circuit with transimpedance amplifier is chosen as the most suitable for the required application. The next step is to select the proper electronic device. According to technical catalogues classical operational amplifier TEXAS INSTRUMENT OPA657 was proposed. Nevertheless program simulation of the designed cicuit shows that required bandwidth cannot be reached with this device. At last transimpedance amplifier ANALOG DEVICES AD8015 comes into account as suitable solution. Final analysis and calculation determine the designed circuit with this device for range up to 240MHz of output signal.
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Advancements in the development of a proportional counter measuring system
Kolář, Ondřej ; Kubíček, Michal
This paper is an interim report of theory and continuouswork on the proportional counter measuring system. Thefirst part of the article covers general principles and propertiesof several types of electronic detectors for measuring the ionizingradiation fields including the proportional counters, to highlighttheir positives and negatives. The following part discusses theprocessing of proportional counter output signal. Next, theconducted measurement of a neutron source is described, and itsresults are shown. Based on the gained experience, the simulationand design of a new preamplifier for the measuring system wascarried out.
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Interface for plethysmographic sensor
Špánik, Šimon ; Barcík, Peter (referee) ; Kolka, Zdeněk (advisor)
The bachelor's thesis deals with the topic of photoplethysmography and the signal produced by the photoplethysmographic sensor. The goal is to design a laboratory device that would serve as an interface between a photoplethysmographic sensor and a computer. The work describes the anatomy and function of the human heart, the principle of photoplethysmography, and the properties of the sensor in terms of input and output signals. Also presented here is the method of powering and filtering the relevant circuits in the form of an additional printed circuit board for a standard Arduino microprocessor module, which is powered by USB. Furthermore, in the work, it is possible to find a solution to the influence of unwanted signals using filter analog circuits and the minimization of the measured signal's own noise, which prevents the signal from continuous values to discrete time and subsequent storage using a computer application on the data storage for subsequent signal processing.
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Detector of optical beam position
Lukáč, Vladimír ; Barcík, Peter (referee) ; Kolka, Zdeněk (advisor)
The bachelor's thesis deals with the design of an optical beam position detector with the required parameters. The aim was to select a suitable photodetector that captures light rays and converts them into photocurrent, to design photocurrent processing into a voltage signal with linear properties and specified parameters, to convert the analog form of the voltage signal into digital information with which a microcomputer or microcontroller can work. The analog part of the work is simulated in the program OrCAD PSpice, in which the functionality and correctness of the designs is confirmed. The digital part processes the voltage signal to the information of the used channel, its level displays this data on the display.
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