National Repository of Grey Literature 65 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Portable digitally controlled stabilized source of symmetrical voltage
Hynek, David ; Drexler, Petr (referee) ; Mikulka, Jan (advisor)
This thesis deals with a design of a power supply for a measuring equipment for a geophysical mapping intended to do a reconstruction of an electrical impedance of a ground environment of water reservoirs. The power source is going to be used for laboratory measurements and for outdoor experiments. The thesis describes the selection of suitable components, equipment design and testing. The theoretical part explains the functions of used components and the principle of an electrical impedance tomography. The conclusion summarizes the properties of the proposed solution and evaluates the final product.
Utilization and Suppression of Birefringence Phenomena in Optical Fiber Sensory Applications
Motúz, Rastislav ; Hudcová, Lucie (referee) ; Vlček, Čestmír (referee) ; Drexler, Petr (advisor)
The thesis deals with integral and distributed optical fiber sensors of electric current. In the area of integral sensors the analysis is performed by Jones matrix calculus and the simultaneous influence of induced circular and undesired linear birefringence using an ortho-conjugation retroreflector. Furthermore, the proposed conjugation loop variant using half-wave phase retarders is analyzed. The theoretical conclusions are confirmed by simulation and experimental measurement. In the field of distributed fiber optic sensors, analysis and simulation for the detection of plasma currents in thermonuclear fusion reactors, based on the POTDR technique, is performed. An improvement procedure is proposed for circular-shaped vacuum vessel reactors. Plasma current detection procedure in divertor-type reactors have been newly designed and simulated to investigate the effect of the OTDR detector noise on plasma current detection accuracy.
Laser source with fiber-optic output
Roupec, Tomáš ; Mikulka, Jan (referee) ; Drexler, Petr (advisor)
This term project deals with the semiconductor laser components, and how it works. Additionally, there is an optical fiber ant networking with laser. It is written of power and cooling laser diodes and such information suggested the possible involvement of the laser diode. At the end of this work is designed laser´s exciter with charging and adjacent circuits.
Digitally controlled laboratory power supply
Spáčil, Petr ; Drexler, Petr (referee) ; Szabó, Zoltán (advisor)
This bachelor thesis deals with the divison and research of DC voltage sources. It also describes how linear and switch mode power supply works. The 8-bit ATmega16 microcontroller from the ATMEL family of AVR microcontrollers is further described. Part of this bachelor thesis is the desing of the laboratory power supply source 30V / 3A, which is in the topology of switched pre-regulation. The ATmega 16 microcontroller provides measurement and displaying values on the display.
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.
Controller of three-axis nano-metric manipulator
Pernica, Lukáš ; Jedlička, Petr (referee) ; Drexler, Petr (advisor)
This diploma thesis describes the piezoelectric phenomenon and its use for positioning with nanometric precision in laboratory use. In the thesis is description of direct and indirect piezoelectric phenomenon, various types of piezoelectric actuators and ways of their control with the aim of eliminating their hysteresis. The goal is to design a controller for piezo actuator built in the three-axis nanometric manipulator Thorlabs MAX341/M.
Detection of closure of chamber doors for an electron scanning microscope
Obšitník, Michal ; Drexler, Petr (referee) ; Nešpor, Dušan (advisor)
The aim of this work is to design a suitable sensor for the detection of the chamber door position in an electron scanning microscope when the pressure in the vacuum chamber is changed and a control program is assembled to the selected sensor. The detected motion is within one millimeter. In the first part, the work is aimed at getting acquainted with the principle of functioning of the electron scanning microscope and with the basic types of sensors for position and mechanical force detection. Subsequently, the sensors are compared according to three basic categories: price, range, and resistance to external influences. Selected theory-based sensors are tested to exclude inappropriate sensors from use. After testing, the Interlink FSR-402 resistance sensor is selected. The scheme is connected to the sensor and the operation control program is created. The result of this work is a force sensing sensor, which is triggered by the pressure of chamber door on the chamber wall when creating a vacuum and a control program that controls the results measured from the sensor and adjusts them as required.
Simulator of partial discharge signal in the UHF band
Škoda, Martin ; Kasárník,, Milan (referee) ; Drexler, Petr (advisor)
This master thesis deals with the problem of the origin and expression of partial discharges in dielectric materials. In the thesis the theoretical foundations, types and parameters of partial discharges are described. In particular, it deals with UHF (ultra high freqeuncy) electromagnetic radiation using UHF method of partial discharge detection. It also deals with the partial discharge UHF signal simulation. The development of UHF sensor systems for partial discharges requires a dive that can simulate them as accurately as possible. Furthermore, a workplace was designed for simulation and detection of partial discharges and processing of their time and frequency characteristics.
THD Analyzer
Ha, Tuan ; Drexler, Petr (referee) ; Mikulka, Jan (advisor)
This thesis deals with design of a THD analyzer for audio frequency. In the interduction, there is a description of methods of THD calculation and realization of THD analyzer. Suitable computing platform must be chosen with capability to process audio data. The expansion board is designed for audio acquisition. Part of this design is complete program that is capable of displaying spectrum and computing THD.
Laser source with fiber-optic output
Roupec, Tomáš ; Mikulka, Jan (referee) ; Drexler, Petr (advisor)
This term project deals with the semiconductor laser components, and how it works. Additionally, there is an optical fiber ant networking with laser. It is written of power and cooling laser diodes and such information suggested the possible involvement of the laser diode. At the end of this work is designed laser´s exciter with charging and adjacent circuits.

National Repository of Grey Literature : 65 records found   1 - 10nextend  jump to record:
See also: similar author names
1 Drexler, Pavel
Interested in being notified about new results for this query?
Subscribe to the RSS feed.