Volume 49, Issue 7-8, 2014

Issue 7-8, 2014


Vol. 49. No 7-8/2014
Monthly scientific and technical journal
Published by:
The Union of Electronics, Electrical Engineering and Telecommunications /CEEC/, BULGARIA




Nikolay R. Rangelov, Nikolay L. Hinov
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Study of the uncertainty measuring of the detonation velocity in a waveguide of non-electric blasting system
Milka D. Vicheva, Georgi S. Stanchev

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The block-diagram of equipment for measuring the velocity of detonation in non-electrical waveguides for blasting is developed. Calibrated time intervals between two pulses corresponding to the specified distance between the ...  read more

40 years an anechoic chamber for automatic antenna measurements in Department of Communication Engineering and Technologies at Technical University of Varna
Georgi T. Chervenkov, Lyubomir P. Kamburov, Georgi S. Kirov

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The creation and development of the anechoic chamber for automatic antenna measurements in the Department of Communication Engineering and Technologies at Technical University of Varna since mid 1970’s to now days is described ...  read more

Three element broadband acoustic array with constant array factor
Peter S. Apostolov, Georgi P. Georgiev

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In the paper a problem of spatial signals filtration with high selectivity is discussed. To approximate the ideal array factor – Kronecker-δ, approximation method of compressed cosines is used. The approximation with third-degree ...  read more

Sensor and actuator nodes for multi-zone demand-controlled ventilation
Marin B. Marinov, Todor S. Djamiykov, Volker Zerbe

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With sensor-based demand controlled ventilation the ventilation rates are controlled through signals from indoor and outdoor air sensors and so better control of the indoor pollutant concentration and lower energy consumption ...  read more

Cost-efficient metallographic preparation methods of electronic components and assemblies
Georgi A. Farkov, Valentin H. Videkov

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Control of the soldering process and failure analysis are an important part of quality assurance at today manufacturers of electronic components and assemblies. Many methods exist – non-destructive and destructive, each ...  read more

Determine the energy of the impulse scheme for electrical excitation laser type “double impulse”
Svetoslav Т. Ivanov, Yanca N. Kissova

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In most lasers with optical excitation essential element of the emitter except the active environment and optical resonator is a converter of electrical energy in the exciting light radiation – gas discharge or halogen ...  read more

Subtraction procedure for drift and tremor removing from ECG: system level synthesis with Compaan
Tsvetan P. Shoshkov, Georgy S. Mihov

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The electrocardiogram (ECG) is often contaminated with interferences such as drift and tremor. The subtraction procedure has proved its efficiency in removing interferences from the ECG. Development process of such device ...  read more

Buck-Boost ZVS DC-DC quasi-resonant converter: design, modeling, simulation and experimentation
Nikolay R. Rangelov, Nikolay L. Hinov

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In the paper work are shown results from researching of a single transistor Buck-Boost ZVS DCDC Quasi-Resonant Converter. Initially an analysis of the electromagnetic processes in the power part of the circuit has been made. ...  read more