Cascode-based voltage-Amplifier stage

Voltage-Amplifier stages are the basic components of commonly used high gain amplifiers the bias and other parameters of whose are set by the external negative feedback. The typical device that uses the voltage-Amplifier stage is the operational amplifier. Similar constructions can also be created on the basis of discrete transistors. From the circuit designer's point of view, the voltage-Amplifier stage defines the crucial parameters of the whole unit-the amplification factor, dominant pole of its transfer function and the slew rate. In this paper the proposal on construction of the voltage-Amplifier stage based on discrete transistors is described. When connected between the input differential amplifier and the output stage, it allows creating of cheap amplifier for HiFi applications with considerable performance. © The Authors, published by EDP Sciences, 2017

Power source unit of a small airship

This paper describes a proposal on a construction of a power supply module that is intended to be implemented in a small airship. Because the bearing capacity of the airship is limited, simple and efficient voltage converters must be employed. The paper provides a description of a proposal on mutual timing of these converters that leads to eliminating of the interferences caused by the currents that are drawn by the converters. The hereby described method allows the designers to use smaller capacitors and inductors which will result in smaller weight and dimensions of the power supply unit. Furthermore, an example of a voltage converter design is provided in the framework of the paper

Construction of compact step down voltage converter in terms of EMC

At the present there is a wide variety of step down converters on market. Due to differences in converter's prices, parameters and principles of function, it is not that easy to choose a proper one suitable for a concrete application. Moreover, really strict standards are applied in order to achieve high EMC compatibility between different devices. This article tries to show the possibilities of a really low-end DC/DC converter controller AOZ 1284. The set of measurements according to the set specifications and standard EN 61000-6-3 are presented together. Moreover, measures needed to comply to limits of the standard are shown along with it's results. © 2016 The Authors, published by EDP Sciences.Ministry of Education, Youth and Sports of the Czech Republic within the National Sustainability Programme [LO1303 (MSMT-7778/2014)]; European Regional Development Fund under the project CEBIA-Tech [CZ.1.05/2.1.00/03.0089]; Internal Grant Agency at TBU in Zlin [IGA/FAI/2016/036

Dataset of response of a semi anechoic room Frankonia SAC 3 plus driven by the electric field

This document provides real data obtained inside the semi anechoic room Frankonia SAC 3 plus that is certified for measurement of electromagnetic interferences and performing of electromagnetic susceptibility tests in the range from 30 MHz up to 18 GHz. The hereby presented data describe the response of the semi anechoic room to the electric field driven inside. The frequency range of the experiment was from 10 MHz to 80 MHz where the standing waves are most likely to occur. © 2018 The AuthorsMSMT-7778/2014, MŠMT, Ministerstvo Školství, Mládeže a Tělovýchovy; LO1303, MŠMT, Ministerstvo Školství, Mládeže a Tělovýchovy; CZ.1.05/2.1.00/03.0089, FEDER, European Regional Development FundMinistry of Education, Youth and Sports of the Czech Republic within the National Sustainability Programme [LO1303 (MSMT-7778/2014)]; European Regional Development Fund under the project CEBIA [CZ.1.05/2.1.00/03.0089

A monitoring network system and its practical demonstration on a model technological process

In order to deepen students' practical knowledge and understanding of the “Computer Networks” subject, a Monitoring Network System was developed that is able to read, collect and distribute data describing real technological processes. The Monitoring System design is based on Client/Server architecture. The model is represented by the real chemical reactor, which was created for the study of the enzymatic hydrolysis of potentially hazardous chrome-tanned wastes generated during leather manufacturing. Final system should be implemented at the university to the graduates and the system should be modular with possible communication support. The setup of the monitoring system comes with all needed explanation and procedures. © 2018, World Scientific and Engineering Academy and Society. All rights reserved

Electromagnetic field generated by wireless alarm devices

Together with the rise of importance of devices employing wireless networks based on the principle of radio frequency data transfers, also the discussion on harmfulness of the electromagnetic radiation has occurred. The authors of this paper obviously cannot provide unambiguous answers to stop this discussion. On the other way, they can provide the reader of this paper with real data obtained by measurements processed inside a semi anechoic chamber that were performed at several wireless alarm peripherals. The measured values are compared to the technical and hygienic standards so the reader can form an idea of the amount of the radiated energy. Moreover, examples of waterfall diagrams of spectra generated by the devices are also listed in this paper. © 2018 De Gruyter Open Ltd. All Rights Reserved.MEYS, Ministry of Education, Youth and Science; MSMT-7778/2014, National Landcare Programme; LO1303, National Landcare Programme; CZ.1.05/2.1.00/03.0089, ERDF, European Regional Development FundMinistry of Education, Youth and Sports of the Czech Republic within the National Sustainability Programme [LO1303 (MSMT-7778/2014)]; European Regional Development Fund under the project CEBIA-Tech [CZ.1.05/2.1.00/03.0089

Remote controlled gate controller using a GSM network and Arduino platform

Most remote controllers for entrance gates operate on free frequencies 433 or 868 MHz. However, this technology limits the user comfort, as it is usually not common that bi-directional communication is established. A higher comfort of controlling the entrance gates can be achieved by employing the GSM network for transmission of commands and messages between the gate controller and the user. In this case, only a conventional GSM cellular phone is needed to control the gate. A description of such a controller based on the GSM module and Arduino controller is provided in this paper.Ministry of Education, Youth and Sports of the Czech Republic within The National Sustainability Programme Project [LO1303 (MSMT-7778/2014)]; European Regional Development Fund under the project CEBIA-Tech [CZ.1.05/2.1.00/03.0089

RFID reader immunity test against electrostatic discharge

This paper provides a description of an immunity test against the electrostatic discharge according to the standard EN 61000-4-2 that was applied to an RFID reader. The RFID reader was primarily developed for access systems, employing the on-board recognition of the RFID tags. The results obtained by the test are described hereby as well as the discussion on the security of this solution. The results of this experiment are beneficial for the developers of RFID devices, as these devices are endangered by the electrostatic discharge brought by their users. The hereby described results also shown a security hole in a simple access system based on the RFID technology. Details can be found in the paper.Ministry of Education, Youth and Sports of the Czech Republic within The National Sustainability Programme Project [LO1303 (MSMT-7778/2014)]; European Regional Development Fund under the project CEBIA-Tech [CZ.1.05/2.1.00/03.0089

Conditions for testing effects of radio-frequency electromagnetic fields on electronic devices

In the last years, a large growth of radio-frequency electromagnetic interference was detected, especially in the frequency bands from 0.8 GHz up to 6 GHz. Tests of immunity of electrical devices must be carried out, because this type of interference can significantly affect their functionality. The aim of this paper is to explain the issue of electromagnetic susceptibility and describe the conditions of testing the immunity of electronic devices against the radio-frequency electromagnetic field according to the relevant electromagnetic compatibility standards. Also, sample electromagnetic immunity tests on the basic set of the intrusion and hold-up alarm system will be presented. © 2018, World Scientific and Engineering Academy and Society. All rights reserved.IGA / CebiaTech / 2017/006; 2017-2019, Ministry of Education of the Republic of Belarus; MSMT-7778/2014, Novartis Foundation for Sustainable Development; LO1303, Novartis Foundation for Sustainable Development; MEYS, Ministry of Education, Youth and Science; FEDER, European Regional Development Fund; CZ .1.05 / 2.1.00 / 03.0089; VI2017201905

Intensity of EMF generated by electronic safety system devices

As the importance of wireless networks based on radio frequencies increases in time, a space for discussion on harmfulness of the electromagnetic radiation has occurred. On the one hand there are studies showing that a direct influence of non-ionizing electromagnetic waves on the human organism was not confirmed until a certain intensity has been reached. On the other hand, critical voices appear, warning that even low intensities of non-ionizing electromagnetic fields are harmful to the human body, if it is exposed to the radiation for a prolonged time. The authors of this paper have no ambition to resolve this dispute. However, they provide data on the intensity of the electromagnetic fields generated by several components of electronic security system that are operating on the basis of the wireless network. The data have been gained in a specialized workplace and will allow the reader to imagine how intensive the radio signals generated by the battery-operated devices are compared to the current hygienic and technical limits. © The Authors, published by EDP Sciences, 2017