|
|
RF power meter
Hlaváč, Štěpán ; Jedlička,, Petr (referee) ; Drexler, Petr (advisor)
This master’s thesis describes various principles of measurement of electromagnetic waves in a free space and on a line. Used sensors and their real parameters are given for every method. The analysis of protections of high-frequency inputs of measuring instruments is done here and the most suitable method and protections of input for realization are chosen. The analysis of design of secondary protection of high-frequency input is done in this project. The protection of input is realized and measured. The suitable method of measurement is chosen as well as the sensor for measurement of power. The block diagram and circuit diagram of the meter of power are designed. According to designed conception the measuring instrument for measurement of power is realized and its single qualities are measured during the realization. In the final part its precision is measured and the evaluation of results is done.
|
|
|
Vector phase-sensitive measurement amplifier
Rejnuš, Milan ; Vlček, Čestmír (referee) ; Drexler, Petr (advisor)
The master’s thesis describes known methods of signal measurement using principle of synchronous detection. Various methods are presented, their principles are examined and the problems when using them are analyzed. Further, procedures for reduction of adverse effects are described also. Second part of this thesis is focused on the instrument design. The instrument is intended for detection and processing of the output signals in a given optometric system. The proposed device is designed to operate on the principle of synchronous detection method using a vector signal evaluation. Advantages and disadvantages are discussed below.
|
|
|
RF analog fiber optic link
Kelbler, Petr ; Jedlička, Petr (referee) ; Drexler, Petr (advisor)
This thesis analyzes the problem of design analog fiber optic link for transmission high frequency signals. Analog fiber optic link will be used in system for detection and localization a partial discharge activity MOSAD-PD-UHF, where will replace existing solution with coaxial cables, which is not appropriate for highly noise environment. MOSAD-PD-UHF system is developed in department of theoretical and experimental electrical engineering. At the first, MOSAD-PD-UHF system and individual parts of optical chain are theoretical described. In following part are compared a few commercially available analog fiber optic link and design of chosen transmit and receive module are described. . The thesis final part deals with construction of optical link and measured parameters are discussed.
|
|
|
Measurement system for pulsed current source
Myška, Radek ; Križan, René (referee) ; Drexler, Petr (advisor)
This work deals with the description and analysis of suitable methods for measurement of non-periodical high-level current pulses. For pulsed current source design and development a suitable measurement system is required. In this work shunt resistor, Rogowski sensor and magneto-optic sensor are presented. The analysis of their properties is performed in order to design a suitable sensor for test current pulse measurement. A design of Rogowski coil sensor has been made. An experimental measurement of current pulses with short time relations has been performed. The suitability of the coil sensor for non-harmonic waveforms measurement has been evaluated on the basis of measurement results. In case of the magneto-optic sensor a concept utilizing an optical fiber has been proposed. The design of the sensor has been performed also. Individual parts of the sensor were verified. Experimental magneto-optic sensors have been built and their properties have been studied.
|
|
|
Power-Over-Fiber power supply
Kos, David ; Vlček, Čestmír (referee) ; Drexler, Petr (advisor)
This thesis deals with the possibilities of energy transmission by optical fiber for the purpose of powering of electronic systems. It comprises issues of electrical energy conversion to optical energy, coupling the power into the optical fiber, coupling between fiber and opto-electric transducer, conversion of optical energy to electrical energy, and transformation on required voltage levels. The principles of such Power-Over-Fiber are discussed in the first part of the work. Various technologies for the implementation of key system parts and their effectivity are discussed. In the next part, several Power-Over-Fiber commercial devices are compared. Subsequently, systems for Power-Over-Fiber experimental implementations are proposed. They are based on the utilization of semiconductor laser, multimode fiber, photovoltaic cell and related electronic circuits. The final part of the thesis deals with the construction of experimental systems and measurement of parameters of transmitted power and efficiency.
|
|
|
The system of load matching to the energy converter
Halama, Petr ; Mandlík, Michal (referee) ; Drexler, Petr (advisor)
This master’s thesis deals with energy harvesting from the mechanical energy sources. The mechanical energy may be converted into the electrical by means of a vibrational microgenerator. The thesis deals also with the production of energy from different renewable sources. There have been identified conditions for effective transformation of the remaining energy. In order to satisfy these conditions a circuit for load matching to energy harvester has to be used. Four variants of matching circuit have been designed and analyzed in PSpice or LTspice. It has been designed a system of power factor correction controlled by circuit with discrete components and also by microcontroller. For one of these variants a specific integrated circuit has been used. The designed circuits have been built and their parameters haven been determined by measurement.
|
|
|
Holographic records
Žáčik, Michal ; Drexler, Petr (referee) ; Fiala, Pavel (advisor)
Holographic records are relatively new technology. Their application is very wide. They apply in engineering, geology, medicine, communication technologies and in security services. This document discuss about short history of holography, basic principles and properities of used waves. Single types of hologprahy are divided by frequency (wavelength) of used wave. This work addicts to requirements of material properities that are applicable for recording and describes some of materials used for recording. There is also illustrated the basic principle of reconstruction of hologram. There is intended a method of recording hologram for MHz frequencies and also a suitable recording material.
|
|
|
Methods for localization of pulsed broadband signal source
Machala, Petr ; Hadinec, Michal (referee) ; Drexler, Petr (advisor)
The topic of this barchelor’s thesis is the analysis of problems regarding localization of partial discharges (PD) and related PD recording, processing and interpretation in time and frequency domain. In majority of cases the occurrence of partial discharges refers to a certain defect in the measured device, therefore in practice (eg large equipment such as oil transformers) it appears to be very useful and economical to determine the exact position, where PDs are formed. To address these complex issues, it is necessary to design the entire measuring chain from PD detection to measured data processing and localization itself. In terms of data processing and PD localization many different localization and detection methods can be applied, some of them are presented in this documentation. These methods are gradually studied, implemented and afterwards tested using the input data of the experiment.
|
|
|
Laser beam coherence in turbulent atmosphere
Polanský, David ; Drexler, Petr (referee) ; Hudcová, Lucie (advisor)
In the first part of the thesis discusses the function of the laser design and construction of its class. Here is an explanation of coherence and other properties of laser radiation. Listed below are the possibilities of energy distribution in the laser beam. Described in particular Gaussian beam. The paper explains the phenomena of bending and Young's experiment. The paper examines the influence of atmospheric environment in the transmission of electromagnetic waves, defined as light. Particular attention is devoted to atmospheric turbulence. In the second part are first discussed the possibility of measuring atmospheric turbulence and coherence of laser beam parameters. The following is designed to measure workplace coherence width and coherence length in a turbulent environment. At these workplaces were measured. The results of these measurements are also listed in the job. The following comparison of results with theoretical values.
|
|
|
Digitally controlled power supply
Stupka, Dominik ; Drexler, Petr (referee) ; Szabó, Zoltán (advisor)
This document describes design of the laboratory power supply with digital control. Power control consists from a control section which handles communication between the modules and the power section.Into the power section is integrated switching and linear regulator. The designed power supply contains two such modules. To control are used microcontrollers from Atmel. Source parameters are 2 x 30 V / 0 – 3 A. During the construction we have to emphasis on the accuracy of regulation the output values and the modularity of the solution.
|
guest ::
