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SPEECH TRANSMISSION ON A SINGLE-WIRE LINE
Valery V. Frisk,
Ph.D, Department Theory of Electrical Circuits, Moscow Technical University of Communications and Informatics, Moscow, Russia, frisk@mail.ru
Keywords: single-wire line, high voltage, eddy current, sinusoidal signal, speech transmission.
The purpose of this paper is to further the study of the electrical properties and processes in a single-wire transmission line and use it for voice. The experimental research technique consisted in the following. In the beginning transfer possibility on a single-wire line of a sinusoidal signal is investigated. The sinusoidal signal has passed on a single-wire line and was clearly audible in speaker. Spectrum was obtained on this signal output.
This experiment convincingly shows that on a single-wire line it is possible to transmit electric signals. Thus it is possible, to transfer speech, music and the information using single-wire technology.
The further experimental researches consisted in studying of possibility of a speech transmission on a single-wire line. The microphone, the microphone amplifier, the power amplifier, step-up the transformer for creation of a high voltage, the single-wire line, the step-down transformer, the second amplifier power and speaker have been for this purpose involved. A supply of all amplifiers was carried out from separate accumulators. During experiment speaker quite well reproduced speech. As a result, transmission of a speech signal received on a single-wire line.
This experiment has shown that on a single-wire line it is possible to transfer speech with success. Therefore, the single-wire line can be used to develop a speaker system alerts. It will lead to increase of overall performance of a loudspeaker. Will allow for more rapid deployment of work for its installation, as single-wire line is much simpler in design. The single-wire line has smaller weight, hence, it can be developed on the big distance, than two-wire line. It will allow to remain on comprehensible distance from sources of the raised danger, especially at acts of nature or fires. One advantage of the single wire is a loudspeaker, in principle there is no possibility that a short circuit as the second (reverse), no conductive lines. Just allow for the saving of metal. The further development of the given single-wire technology will lead to working out of a single-wire talk-back that will allow to organize single-wire wire communication between two remote subscribers.
For citation:
Frisk V.V. Speech transmission on a single-wire line. T-Comm. 2015. Vol 9. No.7, pp. 97-99. (in Russian).
Results of experiments Results of experiments
Theoretically and experimentally can show that a high AC voltage causes the propagation of eddy currents in the singlewire line [2, 3, 5]. If at the end of a single-wire line set-down transformer, the secondary winding of its low voltage level appears. This voltage can be converted into an acoustic signal. We investigate possibility of passage of a sinusoidal signal from the generator «1» to the converter «5» (fig. I).
—Œ
D-
Fig. 2. Scheme of transmission of audio signals on a single-wire line
We write with a microphone Audi signal reproduced dynamic head BAI and programs free audio file editor Audacity, Fig. 3 shows the frequency spectrum of the audio signal.
From this it can be seen that the spectrum of the signal transmitted on a single-wire line have an extremum at a frequency of 2806 Hz. This experience clearly shows that on a single-wire line can transmit electrical signals, and hence the energy [2, 6], music, speech and information.
We show how to use this single-wire technology can pass it (Fig. 4).
Microphone BMI {Philips SBC MD150/00) for converting speech into an electrical signal. To amplify the signal from the microphone used BMI microphone amplifier (BMI37).
1 - The generator of sinusoidal voltage
2 - Step-up transformer
3 - Single-wire line
4 - Step-down transformer
5 - Tlie converter of an electric signal in the acoustic
Fig. I. The Block diagramme of audio signal transfer on a single-wire line
The experimental scheme for the analysis of the sinusoidal signal transmission on a single-wire line is shown in Fig, 2.
Here the generator El and step-up transformer Tl form a high-voltage AC source. Sinusoidal signal with a fixed frequency of 2,8 kHz from the generator El is supplied to the low voltage coil step-up transformer Tl. The second end of the coil remains free. Next, an electrical signal in the form of eddy currents is distributed on a single line to the primary winding of step-down transformer T2. To the secondary winding step-down transformer T2 is connected dynamic {0.1 GD-13-390) BAI.
Single-wire line
-30dB--36 dB--t2dB
-54 dB-
-S6dB-■72dB- -78dB-
i
l
l j
-90 dB ■ ■ ■ ■
1000Hz Cursor: 2633 Hz (E7) 3000Hz « -51 dB P 5000 HI eak: 2806 №{F7) » -33,2 dB
Fig, 3. Spectral characteristics of low-frequency signal
: 3
-Œ
3-
I 8
1 - Microphone
2 - Microphone amplifier
3 - Amplifier I
4 - Step-up transformer
5 - Single-wire line
6 - Step-down transformer
7 Amplifier 2 S - Dvnamic
Fig. 4. Block diagram of speech transmission on a single-wire line
To further strengthen used first amplifier {TDA2005R). The transformer Tl is designed to boost the voltage of the signal. To one end of the secondary winding of Tl is connected single-wire line. The second end of the coil remains free. At the end of a single-wire line set-down transformer T2. The second winding down transformer T2 is connected a second amplifier (TDAI562Q). This amplifier is connected speaker BAI,
The experimental scheme for analyzing a speech transmission on a single-wire line is shown in Fig. 5.
Microphone amplifier
Single-wire line
Amplifier 2
Fig. 5. Speech transmission on a single-wire line with a microphone and three amplifiers
Work of the given scheme consists in the following. Speech by means of microphone BMI will be transformed to an electric signal. The electric signal amplifies the microphone amplifier and the first amplifier. The amplified signal is supplied to the primary winding of step-up transformer TL The high voltage signal generated step-up transformer Tl, produces a distribution of the eddy current wire line [4]. At the end of a single-line set-down transformer T2. In secon-
dary windings of lowering transformer T2 there is an alternating voltage (signal) of the lowered level. This signal amplifies the second amplifier to size necessary for work dynamics BAI.
The experiment showed that the speaker BAI satisfactorily reproduce it at a reasonable volume level.
As a result, received speech transmission via single-wire technology.
The single-wire technology can be used for working out of a loudspeaker of system of the notification. Loudspeaker converts it into an electrical signal, strengthen it and converts back into sound waves propagating in air. Improving the efficiency of the speaker may have an impact on the quality of the audio transmission, and ultimately on people's lives, especially during natural disasters or fires.
With further improvement may be constructed singlewire intercom and organize single-wire wire connection between two remote sites.
References
1. Sirebkov D.C. 2010, 'Rezonansnye sistemy raspredelenija jelek-tricheskoj jenergii', Jelektrojenergija. Peredacha i raspredelenie, no. 3, pp. 72-75. [in Russian].
2. Frisk V.V. 2013, 'Obnaruzhenie indukcionnyh tokov v linii svjazi', Nelinejnyj mir, no, 8, pp. 73-75. [in Russian].
3. Frisk V.V. 2013, 'Vihrevye toki v odnoprovodnoj linii svjazi', T-Comm, no. 10, pp. 98-99. [in Russian].
4. Frisk VY. 2013, 'Ispol'zovanie odnoprovodnoj linii peredachi dlja pitanija razlichnyh jelektrotehnicheskih ustrojstv', Trudy konfer-encii «Telekommunikacionnye i vychislitel'nye sistemy», 27 nojabrja 201 3 g. Moskva. -M.: lnformpress-94, pp. 106-107. [in Russian].
5. Frisk V.V. 2014, 'Researches of electric processes in a singlewire line and in the flat condenser', T-Comm, no. I, pp. 58-59. [in Russian].
6. Frisk V.V. 2014, 'Vihrevye toki v odnoprovodnoj linii', Trudy konferencii «Telekommunikacionnye i vychislitel'nye sistemy», 26.1 1.2014. - M.: lnformpress-94, 2014, pp. 107-109. [in Russian].
ПЕРЕДАЧА РЕЧИ ПО ОДНОПРОВОДНОЙ ЛИНИИ
Фриск Валерий Владимирович, к.т.н., доцент, Московский технический университет связи и информатики
(МТУСИ), Россия, Москва, frisk@mail.ru
Аннотация
Целью данной работы является изучение электрических свойств и процессов в однопроводной линии передачи и применение её для передачи речи.
