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Non-linear circuit structures with active current elements
Langhammer, Lukáš ; Lattenberg, Ivo (referee) ; Koton, Jaroslav (advisor)
This thesis deals with non-linear curcuit structures with current active elements. In its introduction this work deals with a description of the current conveyor. Further the text pays attention to the possiblities of the circuits for modification signals in analogue technology. First are described circuits of diode limiters and transducer. Great attention is paid to the amplifiers with current active parts. In conclusion are realized circuits of universal precise full-wave rectifiers using operational amplifier and current conveyor and made comparisons.
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Electronically tunable frequency filters
Štěpán, Radim ; Jeřábek, Jan (referee) ; Herencsár, Norbert (advisor)
This bachelor thesis deals with a proposal of electronically controllable filters by means of modern active elemental parts such as current conveyors, transconduct amplifiers or programmable current amplifiers. The suggestion of new connection of frequency filters uses graphic chart of active and passive elements. In the introduction there is described the survey of signal flow graphs, modern active elements suitable for proposal frequency elements. The procedure of proposal of controllable frequency filter based on set typical formula of designed circuit is demonstrated as an example. On a basis of different modifications the designed circuit is made with various types of active elements. Simulation results of the program PCspice confirmed the proper working of the proposal circuits.
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Electronically tunable oscillators
Polanský, David ; Šotner, Roman (referee) ; Petržela, Jiří (advisor)
The goal of bacheolor’s project introduce the reader to the basic principles of oscillator with a possibility of coherent electrical tunning frequency. Project is focused on utilization of non-standard active elements like OTA and CCII. A few wiring circuits are listed, in which it's tunning scale is calculated in PSpise program. Next these devices are compared.
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Multifunctional analog frequency filters
Žůrek, Radomil ; Koton, Jaroslav (referee) ; Minarčík, Martin (advisor)
Main topic of this bachelor thesis are the frequency filters and their application. It presents multifunction frequency filter circuits with focus on active circuit elements like current conveyors (GCC), voltage conveyors (GVC) and transconductance amplifiers (OTA), which operate in both voltage and current modes. Then it presents the outcomes of designing 26 second order frequency filters, all operating in both voltage and current modes. It discusses in theory the problematics of M-C graph design, which is graphics-based analogy of voltage and current incidental matrices. Selected circuit designs are examined as examples with their transfer functions determined and results presented as module frequency characteristics. Individual M-C graphs (signal flow graph) are designed for each filter circuit. In conclusion are summarized the characteristics of M-C graphs and their suitable applications.
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Controlled analog frequency filters
Martinek, Pavel ; Koton, Jaroslav (referee) ; Minarčík, Martin (advisor)
In this bachelor’s thesis are described elements frequency filters, especially OTA amplifier, current and voltage conveyor. There're presented possibilities of control frequency-selection filters and components to control, analog multipliers, DA converters, controlled amplifiers and digitally controlled potentiometers. There are discussed some circuits of controlled filters and their possibilities of independent control of parameters f0, Q. Frequency characteristics for mentioned filters are verified simulator programme. The circuits are modified to other type filter and again frequency charakterestics are verified simulator programme PsPice.
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Universal precision rectifiers with current active elements
Ryšavý, Lukáš ; Jeřábek, Jan (referee) ; Langhammer, Lukáš (advisor)
In this thesis new circuit solutions of universal precision rectifiers with current active elements are proposed. Based on the knowledge of current active elements, universal precision rectifiers and adverse impacts on these circuits new circuit solutions are proposed. These circuits are then simulated and compared with the known circuits of precision rectifiers. In concusion two original circuits and two proposed circuit solutions based on original ones are implemented, their properties are experimentally measured and their function are verified. The main active element in the original circuit are the OPA or THS, the proposed circuits are used the OPA and THS and the universal current conveyor, which offers a wide range of application use and realization of different variations of active current elements.
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Oscillators and function generators using current and voltage conveyors
Šťastný, Lukáš ; Jeřábek, Jan (referee) ; Koton, Jaroslav (advisor)
Conveyors are an integral part of modern devices. In this thesis, a slew of areas oscillators and function generators with current and voltage conveyors. Individual applications are categorized according involvement with conveyors and other elements. The functionality of the need for involvement in the program PSpice simulation. As a current conveyor is used OPA861, EL2082, further use of RC circuits and opto-CNY 17.
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Nonlinear circuits using current active elements
Langhammer, Lukáš ; Kubánek, David (referee) ; Koton, Jaroslav (advisor)
This thesis deals with non-linear curcuit structures with current active elements. In its introduction this work deals with a description of the current active elements, such as current conveyor, transconductance operational amplifier and current follower. Further the text pays attention to the possiblities of the circuits for modification signals in analogue technology. First are described circuits of diode limiters and transducer. Great attention is paid to the amplifiers with current active elements. Are propřed simulated and practically realized circuits of universal precise full-wave rectifiers using operational amplifier and current conveyor and made comparisons of known and proposed circuits. The paper also discussed other circuit structures using of current active elements, such as multiplier, divider, a triangular signal generator and oscillators.
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Versatile autonomous circuit equivalents of floating and grounded passive elements
Štěpán, Radim ; Koton, Jaroslav (referee) ; Herencsár, Norbert (advisor)
This thesis deals with a proposal of versatile autonomous circuit equivalents of floating and grounded passive elements by means of modern active tectonic blocks, such as current and voltage conveyors of all three generations. Current conveyors range as essential tectonic blocks in a current mode. Concerning signal processing, it encompasses a mixed tectonic block. In most cases, these elements may be substituted for presently insufficient operating amplifiers. The voltage conveyor was defined on the basis of duality of current and voltage modes. This element could be selected as a suitable active component for circuits operating in a voltage mode. Implementing the connection, a general autonomous circuit is taken into account. By selecting given admittances, a FDNR (floating frequency dependent negative resistance) element, floating capacitance, floating inductance and ground to floating admittance converter may be implemented. The practical part describes connections which fulfill given requirements. The suggested elements are simulated in comparison with ideal elements and subsequently, they are applied to a frequency filter. The second order filter with a proposed induction coil was practically assembled and experimentally measured in a laboratory. The measured results were compared to simulations received by the use of ideal and real models of current and voltage conveyors.
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Analysis, features and applications of available current mode multipliers
Miksl, Jan ; Jeřábek, Jan (referee) ; Šotner, Roman (advisor)
The diploma thesis deals with analysis, validation, measurement of parameters of the commercially available current multiplies (namely the EL2082 and EL4083) and their applications in practice. Control analysis are carried out in OrCAD PSpice program and compared with values from datasheets. Control analysis are focused on AC and DC characteristics of these active blocks. There are discusses the input impedance, the output impedance, the current gain and the possibility of electronic adjusting. The parameters of the elements were verified by measurements. Proposals for circuit applications (selective circuit, oscillator, frequency filter) with EL2082 and EL4083 are presented and analyzed in the program OrCAD. Three oscillator circuit designs are experimentally tested and the results are compared with the theoretical expectations and simulations in OrCAD. The possibility of electronic control for oscillators is examined. Also the sensitivity and the tolerance analysis are carried out. The constructional details of oscillators are presented at the end of this work.
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