US1189411A - Telephone transmission system wherein reinforcing-repeaters are employed. - Google Patents

Description

ALBERT SIMON JonAN VAN KESTEREN; or vL ssmGEn, NETHERLANDS.

TELEBHONE TRANSMISSION sfzsrnn WHEREIIT BEINFORCING-REPEATERS ARE EMPLOYED.

Specification of Ltters Patent.

Patented July 4, 1916;

Application filed December 19, .1913. Serial No. 807,749,

To 117 l wit-mu it 112 (11 concern Be it known that l. ALBERT Sums Jonas: YAX Kizs'rnmix, a subject of the Queen of the Netherlands. and residing at- Vlissingen, Province of Zeeland. Xetherlands, have invented certain new and useful Improvements in and Relating to Telephone Transmission Systems \Vherein Reinforcing-l epea-ters Are Employed, of which the following is a specification.

This invention relates to telephone transmission systems comprising repeaters for reinforcing the current wavesbetween two subscribers? stat-ions.

According to this invention, a long dis tance; line for conversation in each direction between the stations is provided, which two lines are connected at their ends to each other and also to lines leading tov each subscribers station, the latter connections being positive or inductive, while the total damping of the two lines between the points of connection is made equal to,-or greater than the total reinforcing produced by the repeater or repeaters. This arrangement allows conversation in both directions to be carriedon, without it being'nccessaryto balance portions of the lines, or use reversing switchesi v p Figure 1} of the accompanying drawing shows diagrammatically an, unsuitable system subject to the so-called buzzing or howling,. Fig. 2' shows a system according tothis invention, with one repeater for each; tall;- ing direction. Fig. shgowsa system. with several repeaters for each; talking. direction. Fig. 41 shows a system accordingto this in.-

vention. with one-relay only for both direc-' tions of talking.

Inthe system according to Fig- 1, which has not proved satisfactory in practice, the repeaters T,,.T; areins'ertediintheline c-c ata point intermediatethe talking stations C and D. It was held that. the talking curby therepea'ter T so that it becomes audible at station D, and that the talking current produced at D, is strengthened by therepeater T sothat it becomes audible at staaction. is diiferent. The talking current emanating from T, divides at the junction m, and one portion reaches thereceiver a, of the repeater T appears strengthened at b and 1 divides at. the junction 2 part then going rent prod'ucedf at stationis strengthened 60110. It has been found, however, that the through. a, into the repeater T and being transmitted reinforced tob and so on. The result is that buzzing is heard in the receivers of. the subscriber's stations, and the system is unsatisfactory. i

Fig. 2 shows a system according to this nvention.v In a long distance line comprising the parts L and L a repeater T is inserted of which a, is the receiving and b the transmitting side. The repeater T thus transmits talking'currents only in the direction. from station A to station B. The sec- 0nd line L and L transmits talking currents only in the direction from B to A, as

the repeater T is arranged with its receivlng side a, connected to station B, and'its transmitting side 6 connected to station A- zit points and q the sending and receiving lines are connected to each other and to lines leading tothe subscribers stations. The

connections tothese latter may be either direct or inductive. The lines g.A and pB may be themselveslong distance lines, so that the pointsp and g need not be near in Fig.1, will. appear in the system shown.

in 2",. as any current wave circulating in the circuit q, L,,, T 11,, 12,. L '18,, p

rapidly diminishes to zero value, as it is being: constantly damped to a greater extent, than it is reinforced.

If-xthodamping! in the line L L should be smaller than the reinforcing in said line then. in order that there should be no inadmissible howling currents, the reinforcing in the line L L must be smaller by at least. the same extent than the damping in the same line. In this case, at the point 9,

talking currents arrive which are stronger than those set out from the point p. At.

thepoint p, on the cont'rary,currents are received which are weaker than the currents sent out fromthe point 9.

It follows from the foregoing that the lines L L, and 11,. L. need not be balanced.

As the talking currents passing through the points 7) or 9, after having passed through the long distance lines, are received at the points 9 or p with little or no Weakening. the lines between A and g or between B and 1) may be of considerable length.

Fig. 3 shows an arrangement in which a number of repeaters T and '1 are inserted at arbitrary points in the long distance lines L and L The above mentioned rule applies also here, so that the total reinforcing by the repeaters T and T may at the outside be equal to the total damping in the lines L, and L between the points 79 and 9.

Fig. 4 shows a system in which the reinforcing can be effected by means of a single repeater. In this arrangement it is necessary to insert the repeater T between two long distance lines L, and L at such a distance from the junction points 79 and 9 that neither of the two circuits on the right and left hand side of the repeater T the damping will be smaller than the reinforcing. These two circuits of course need not be balanced. If the damping of the current waves in one of the two circuits situated laterally of the relay T were less than the reinforcing by the repeater T howling would take place, as described above with reference to Fig. 1. Apart from the fact that the system of Fig. 4 is not so good as the system of Figs. 2 and 3, owing to the situation of the repeater T being incapable of much variation, the system-of Fig. 4 is less efficient than the first described two systems.

The double wire lines illustrated may be obviously replaced by single wire lines with earth return, without departing from the invention, and the invention can be used in systems other than those diagrammatically illustrated.

aving thus described my invention, what I claim is: I

1. In a telephone system comprising at least one repeater for strengthening the current waves between two subscriber stations, a line for conversation in each direction between said stations, the said separate lines being electrically connected at the ends to each other and also to each subscribers station, the said lines being of such extent that the damping therein between the two points of connection is equal to, or greater than, the total strengthening produced by the re peater.

2. A telephone transmission system comprising in combination, a pair of parallel lines connected at the ends to each other and also to lines going to each subscribers station, and repeaters placed in said lines and so arranged that one line is used only for transmission in one direction and .so that the total damping in a closed circuit composed of said parallel lines is greater than the total reinforcing of the repeaters.

In testimony whereof I affix my signature in presence of two witnesses.

ALBERT'SIMON JOHAN VAN KESTEREN.

lVitnesses:

' J. A. HOOGIIAMEN,

CHR. F. Knnnsnx NEKER.

Copies of thil patent may be obtained for five cents each, by addressing the "comlilsioner of Intent,

Wmhingtm, n. c."

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