|
|
Adaptive antialiasing frequency filter
Sovadina, Václav ; Murina, Milan (referee) ; Sedláček, Jiří (advisor)
The aim of this project is to become acquainted with the Bessel approximation function and to present the possible connections of the adaptive antialiasing filter. Then, cascade and partition filter realizations are designed and their computer analysis are carried out. Furthermore, the thesis deals with the options of electronic realignment of filters. A common connection of digital potentiometer along with the block diagram of the whole mechanism are described. The next part presents a construction of the analogue part of the filter, measuring of its real characteristics and the control circuit for the analogue part.
|
|
|
Adaptive active band - pass
Velička, Pavel ; Murina, Milan (referee) ; Sedláček, Jiří (advisor)
The aim of this thesis is to find and propose solutions adaptive ARC frequency bandpass filter, where it will be possible to change the bandwidth and tuning the center frequency. Centre frequency will be tuning in the range from 10kHz to 100kHz. Bandwidth is tunable to the maximum range that will enable us to select involvement. The thesis selected two methods of implementation of the filter. It made the comparison and selection of improved variants. Thesis includes calculations of the resulting variant filter and describes how to tune the filter, and then simplify the tune selected filter. Bachelor thesis includes a complete filter design for its implementation. A suitable method of electronic tuning were selected digital potentiometers controlled programmed microcontroller. This method was also subsequently implemented.
|
|
|
Sound source localization
Vélim, Jan ; Brejl, Milan (referee) ; Fedra, Zbyněk (advisor)
The paper discusses a possibility of localization of a sound source inside a wooden beam. The method is based on measuring signals from two microphones, assuming the sound source lies between the microphones. The position of the sound source is calculated from the delay between the signals. The calculation of the delay is done by correlation of the signals in the frequency range. ARM architecture microcontroller is used to for the calculations.
|
|
|
Digitally controlled power supply
Madron, Martin ; Šotner, Roman (referee) ; Kubíček, Michal (advisor)
This bachelor´s thesis is about design of digitally controlled power supply. The introduction describes the basic principle of power supplies and their division. The thesis deals with solving the adjustable current source with adjustable current cutout. The solution of supply was made using linear stabilizers L200 controlled by digital potentiometers. Control handles microcontroller ATmega16 from Atmel. The user interface is realized by the matrix keyboard and LCD display. At the conclusion of the work there is a selection of the structural components.
|
|
|
Electronically controlled active 2-nd order filter
Ševčík, Břetislav ; Petržela, Jiří (referee) ; Šotner, Roman (advisor)
The diploma thesis deals with the modern design of the control circuits for digital potentiometers and their application in analog systems. The concept of the digital control is demonstrated on the electronically controlled active 2-nd order filter and programmable oscillator. The proposed design of the active filter describes a programmable active 2-nd order filter Sallen-Key. In this circuit it is possible independently programme cut-off frequency, Q factor and type of approximation with very good accuracy. The circuits of the designed filter and designed oscillator are simulated in PSpice (OrCAD), parasite effects and effects of the real parts are studied. Properties simulated circuits are compare with experimental results. These results appreciate quality and efficiency of the digitally controlled potentiometers in dependence on variable input circuit parameters. Integral part of this project is author’s universal control program called Digipot and comunications interface for many types of digital potentiometers with I2C, SPI or Up/Down interface. It is possible to use this device for many applications. The constructional details of the filter are presented at the end of this work. The software equipment is availability on enclosed CD.
|
|
|
Frequency filters controlled via microprocessors
Bronec, David ; Kincl, Zdeněk (referee) ; Biolková, Viera (advisor)
This thesis is focused on the microprocessor-controlled frequency filter project. The main goal of the thesis is to present basic terms and principles of frequency filters and active frequency filters for cascading synthesis. Furthermore, the work contains information on digital potentiometers. The thesis includes circuit simulations and a project of connecting with a printed circuit board. The last chapter contains the results of the measurements.
|
|
|
Control unit for Eurorack audio modular system
Zach, Pavel ; Novotný, Radovan (referee) ; Levek, Vladimír (advisor)
The aim of the thesis is to design and implement a control system for a Eurorack modular audio system. The system consists of a voltage controlled oscillator, circuits for its control and is equipped with MIDI connectivity. The theoretical part describes the different sound synthesis methods and how the synthesis is implemented. Furthermore, the text discusses the integrated circuit used and the MIDI protocol itself. The practical part focuses on the design of the control block, which contains a voltage controlled oscillator. The module provides signals for other modules of the Eurorack platform and is capable of communicating with a computer and other MIDI peripherals.
|
|
|
Microcontroller-based graphic equalizer
Šmotek, Jiří ; Šebesta, Jiří (referee) ; Dušek, Martin (advisor)
This bachelor's thesis deals with problems of correction of audio-signal by help of equalizer. The first part discusses the fundamental properties of electronic filters. The second part describes graphic equalizer and its schematics. A simulation of this suggested connection is executed in the PSpice software. Furthermore, the circuit diagram is presented and the proposal of PCB design equalizer is realized using the digital potentiometers instead of the classic potentiometers. Following part is then focused on description of a programme for the microcontroller and PC. The last part finally presents the measurement.
|
|
|
ARC filter for frequency analyser
Janečka, Martin ; Murina, Milan (referee) ; Sedláček, Jiří (advisor)
The aim of this work is to propose and realization an active frequency filter with a 4th grade bandpass for making it possible to electronically tune the resonant frequency in range of 10Hz to 100kHz and adjust bandwidth. The thesis discussed two possibilities of filter connections using cascade synthesis. To choose a better option a filter simulations were made in Pspice. Based on the simulations, the number of components and the possibility of electronic tuning a better option is selected. This circuit is implemented, measured and then compared with simulations.
|
|
|
Digitally controlled multifunction filter
Hubka, Patrik ; Kubíček, Michal (referee) ; Ševčík, Břetislav (advisor)
he bachelor thesis deals with the modern design of analog filter where the digital potentiometers to control circuit parameters are used. The main purpose of this thesis is to create a fully digitally controlled filter at frequencies above 1 MHz based on LT1568 integrated circuit. The main circuit parameters such as cut-off frequency, gain, filter order and type of approximation function are digitally controlled. Analysis of parasitic effects of digital potentiometers is included. The integrated circuit functionallity is demonstrated by LTspice circuit simulator. Finally, the experimental measurement results for various circuit parameters setting are included.
|
guest ::
