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Adaptive frequency filter
Dolák, Jan ; Murina, Milan (referee) ; Sedláček, Jiří (advisor)
This thesis deals with passive and active frequency filters and their realization. The mail goal of my thesis was to design, simulate and realize adaptive frequency filter with the possibility of alternating it's parameters. The designed filter should be an active band stop filter of fourth kind with the possibility of alternating it's resonance frequence f0 and it's coefficient of quality Q. At the beggining it was needed to study the theory of frequency filters, types of frequency filters, which are often used in praxis, their properties and ways of their realizations. Use of active filters with operational amplifiers was optimal possibility of their realization. Because of there was given them the biggest attention in this part of the thesis. Then it was searched the most acceptable solution of required band stop filter, witch would have the best properties. Digital potentiometers operated by microcontroller were chosen for setting different values of various parameters. Designed circuits were realized after the decision and adaptation of optimal wirings and then the programme for operating of microcontroller and digital potentiometers was configured. By this way designed circuits were experimentally measured.
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Non-linear Circuits with Controlled Current Sources
Dolák, Jan ; Hanák, Pavel (referee) ; Kubánek, David (advisor)
This thesis treats of problems of nonlinear circuits. In introduction the basic possibilities of solving nonlinear circuits are described. Then the basic information on modern current active elements is mentioned, for example current follower, current operational amplifier and current conveyor. In the next part of this thesis the problem of real characteristics of semiconductor diodes is described, major attention is focused on reverse recovery time. Three various types of circuits with nonlinear elements are described in this masters thesis. The first type of circuits are diode precision rectifiers, the full-wave rectifiers containing voltage operational amplifier are most explored, current follower and other active components are described in previous chapters. Simulations in PSpice were executed for each of these circuits. Then the attention was devoted to increase of maximum working frequence. The minimum necessary amplitude of input signal was also analyzed. In the following part two designs of diode function converters are processed, function converter with voltage operational amplifier and function converter with current follower. For each of the diode function converters designed, simulations were executed to find their real properties. The variety of diode voltage limiters and diode current limiters are the third type of nonlinear circuits described, from which the upper limiter and double limiter are investigated in more detail. Simulations were executed for all limiters and their functionality and problems connected with their usage for limitation of high frequency signals were analyzed. In the last part of the thesis there is described the practical realization of precise rectifier, which showed the best ability to process high frequency signals of all investigated circuits. This circuit was realized so that it is able to operate in current and mixed mode. Measured values of real circuits were compared with values gained from the simulations.
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The history of physical education and sport in unions of the Kosmák region of Orel
DOLÁK, Jan
The bachelor's thesis deals with the history of physical education and sport in Kosmák County Orel. Kosmák County was established by agreeing to the division of West Moravian County at the General Congress of the Czechoslovak Eagle on July 31, 1947. The named county is based in Znojmo and the individual units are from the Znojmo region. However, the activities of this county were stopped by the communist regime. After many years under the communist regime, the county was successfully restored on January 1, 1996. In the individual phases after the restoration, unities were formed, but they did not survive on the Eagle scene and ceased their activities. Kosmák County now has 6 units: Mramotice, Pavlice, Přeskáče, Únanov, Vémyslice and Znojmo. The work further clarifies the life of the county patron Václav Kosmák. Secondly, it focuses on the course of Orel's activities from the beginning to the present and describes the personality of Orel's physical education, Jan Šrámek.
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Adaptive frequency filter
Dolák, Jan ; Murina, Milan (referee) ; Sedláček, Jiří (advisor)
This thesis deals with passive and active frequency filters and their realization. The mail goal of my thesis was to design, simulate and realize adaptive frequency filter with the possibility of alternating it's parameters. The designed filter should be an active band stop filter of fourth kind with the possibility of alternating it's resonance frequence f0 and it's coefficient of quality Q. At the beggining it was needed to study the theory of frequency filters, types of frequency filters, which are often used in praxis, their properties and ways of their realizations. Use of active filters with operational amplifiers was optimal possibility of their realization. Because of there was given them the biggest attention in this part of the thesis. Then it was searched the most acceptable solution of required band stop filter, witch would have the best properties. Digital potentiometers operated by microcontroller were chosen for setting different values of various parameters. Designed circuits were realized after the decision and adaptation of optimal wirings and then the programme for operating of microcontroller and digital potentiometers was configured. By this way designed circuits were experimentally measured.
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Non-linear Circuits with Controlled Current Sources
Dolák, Jan ; Hanák, Pavel (referee) ; Kubánek, David (advisor)
This thesis treats of problems of nonlinear circuits. In introduction the basic possibilities of solving nonlinear circuits are described. Then the basic information on modern current active elements is mentioned, for example current follower, current operational amplifier and current conveyor. In the next part of this thesis the problem of real characteristics of semiconductor diodes is described, major attention is focused on reverse recovery time. Three various types of circuits with nonlinear elements are described in this masters thesis. The first type of circuits are diode precision rectifiers, the full-wave rectifiers containing voltage operational amplifier are most explored, current follower and other active components are described in previous chapters. Simulations in PSpice were executed for each of these circuits. Then the attention was devoted to increase of maximum working frequence. The minimum necessary amplitude of input signal was also analyzed. In the following part two designs of diode function converters are processed, function converter with voltage operational amplifier and function converter with current follower. For each of the diode function converters designed, simulations were executed to find their real properties. The variety of diode voltage limiters and diode current limiters are the third type of nonlinear circuits described, from which the upper limiter and double limiter are investigated in more detail. Simulations were executed for all limiters and their functionality and problems connected with their usage for limitation of high frequency signals were analyzed. In the last part of the thesis there is described the practical realization of precise rectifier, which showed the best ability to process high frequency signals of all investigated circuits. This circuit was realized so that it is able to operate in current and mixed mode. Measured values of real circuits were compared with values gained from the simulations.
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