|
|
Design of the voltage controlled oscillator
Richter, Vladimír ; Pavlík, Michal (referee) ; Háze, Jiří (advisor)
This bachelor thesis deals with the issues of voltage controlled oscillators. It analyses their current state and provides the examples of them. It also describes phase locked loop stages and the usage of voltage controlled oscillators in phase locked loops. The main aim of this thesis is to design a voltage controlled oscillator and use it to realize the important simulations.
|
|
|
Digital audio interface converter with an external PLL
Klubus, Jan ; Balík, Miroslav (referee) ; Hanák, Pavel (advisor)
The design of the learning hardware for the laboratory role of the BSHE, which will serve as a test sample, and will permit students to display signals in individual parts of the circuit using an oscilloscope. This device convert the S / PDIF and AES3 signal, it have a line and headphone output and the phase lock loop will be output separately for signal tracking.
|
|
| |
|
| |
|
|
Laboratory High-Frequency Generator
Konzal, Jan ; Záplata, Filip (referee) ; Šebesta, Jiří (advisor)
This thesis describes a proposal of laboratory high frequency generator based on the principle of indirect analogue synthesis with a phase sling. The first part of the work describes the principle of a direct numerical and indirect analogue synthesis. Frequency range of the designed generator is up to 900 MHz. The output of the generator is designed to be up to 12dBm. Output impedance is 50 . To reach a frequency of oscillation lower than 800 MHz, the principle of fusion is used. Further, the control was suggested to be carried out by a microprocessor. Operating is realized using a keyboard and a rotary encoder.
|
|
|
Concept of three-phase active rectifier
Bareš, Jiří ; Pazdera, Ivo (referee) ; Huták, Petr (advisor)
This work deals with three-phase active rectifier control. In first, theoretical part it describes several control strategies with focus on voltage oriented control. For this type of control a design is worked out, and created model and its simulation is described. Second, practical part deals with realisation on microcontroller TMS320F28335, which is main processing unit of device lent by company Elcom. Therefore in this part abilities and settings of the controller along with developped control algorithm are described. Reached results of measurement are then presented and in the conclusion they are evaluated.
|
|
|
Power source for pulse magnetron sputtering
Schulz, Jakub ; Magát, Martin (referee) ; Šteffan, Pavel (advisor)
The presented thesis deals with the design and assembly of the generator for pulse magnetron sputtering. The designed device is capable of generating two square wave signals via its counter-working outputs. Both signals have independently adjustable frequency, pulse count and duty ratio. Both signals originate from two frequency syntheses controlled by microcontroller PIC16F877A. All the settings are entered by four buttons and are shown on an alphanumeric display with 16x4 characters. The duty ratio is adjusted using a special module.
|
|
|
Laboratory Model of the Vortex Speed Indicator
Kazda, Ondřej ; Kolka, Zdeněk (referee) ; Biolková, Viera (advisor)
This work is concerned with posibility of measuring a wind flow by Von Karman vortex sheed structure. The bluff body is situated in the way of air flow propagation and consequentally vortexes will be appeared. Important part of speedmeter design is measurment chamber must allow to vortex sheed propagation. The transient and the reciever are situated vertically to propagation of flow.The Ultrasonic carrier is transmitted and modulated by freqency of vortex sheeding in measurment chamber.Demodulator uses PLL to “focusing“ detection of the ultrasonic beam. This can be indicated like lock and unlock phase loop. From known value of sheed frequency can be directly calculated speed of flow.
|
|
|
Spectrum Analyzer up to 500 MHz
Čada, David ; Vimperk), Tomáš Baráth (Rohde Schwarz (referee) ; Šebesta, Jiří (advisor)
This project deals with design and realization of the spectrum analyser using double superheterodyne topology with frequency range up to 500MHz. This work solves hardware blocks like phase lock loops, intermediate frequency filters, saw filter, crystal filter, logarithmic detector. Content of work is also design description and tuning of spectrum analyzer parts.
|
|
|
Design of magnetic bar-code read head
Kadlčík, Libor ; Drexler, Petr (referee) ; Mikulka, Jan (advisor)
Magnetic bar-code is composed from ferromagnetic bars printed on a substrate. The amount of ferromagnetic material is low, therefore reading magnetic barcode requires sensitive methods. Principle of methods of sensing both low-intensity magnetic field (fluxgates) and detecting low concentration of ferromagnetic material (resonant circuit, differential sensor) will be described. There are sensors producing frequency-modulated signal, therefore we focus on frequency demodulators as well. Signal acquired by sensor suffers from convolution distortion, reconstruction methods will be introduced. The assembled device consists of sensing oscillator, frequency demodulator, amplifier and reconstructing circuit. Frequency demodulation is done by phase-locked loop or differential demodulator. Reconstruction is based on detection of inflection points, producing square signal (representing bars of barcode). Design of these blocks is described. The device is able to read magnetic barcodes and reconstruct convolutionary distorted acquired signal. The differential demodulator exhibits low noise and low temperature drift (contrary to phase-locked loop). Signal produced by reading 2 mm wide bars is reconstructed without any problems, bars of width less than 1 mm cause troubles in certain cases (due to high degree of convolution distortion).
|
guest ::
