US1722039A

US1722039A - Signal-operated repeater circuits

Info

Publication number: US1722039A
Application number: US158195A
Authority: US
Inventors: Homer W Dudley
Original assignee: Bell Telephone Laboratories Inc
Current assignee: AT&T Corp
Priority date: 1926-12-31
Filing date: 1926-12-31
Publication date: 1929-07-23
Anticipated expiration: 1946-07-23
Also published as: DE510103C

Description

July 23, i929 H. W. DUDLEY l LZZDQSS SIGNAL OPERATED REPEATER CIRCUITS original Find Dec. s1. 192e Hg z Patented July l 23, 1929.

UNITED STA-Tas PATENT OFFICE.

HOHER W. DUDLEY, OF BROOKLYN, NEW 4YORK, ASSIGNOB TO BELL TELEPHONE LABORATORIES, INCORPORATED, OF NEW YORK1\l'.K Y., A CORPORATION OF NEW YORK.

SIG-NAL-OEIERATEl) BEPEATER CIRCUITS.

Application iled December 31, 19255, Serial No. 158,195. Renewed April 25, 1928.

This invention relates to signal operated' repeater circuits in which one-way repeaters are arranged to be automatically pomted in the direction in which signal Waves are b'eing transmitted over a two-way line.

An object of the invention is to simpllfy signal operated repeater circuits.

Another object of the invention 1s to provide an improved signal operated repeater circuit for use between relatively noisy and relatively quiet signal lines.

Heretofore, so-called signal or voice operated repeater circuits have been of two general types, one, the so-called biased type 1n which a repeater is left in condition to transmit-.eciently only in the direction in which it last transmitted until transmission in the other direction is initiated, and the other, the so-called neutral type in which, between periods of transmission, the repeater is not 1n condition to transmit ehciently in either direction.

In accordance with a feature of this invention, there is provided a repeater which 1s normally pointed in one direction, regardless of the direction in which transmission last took place, but which is pointed in the other direction when transmission in that direction is initiated.

In accordance with another feature of this invention, several repeaters of the above type are employed in a transmission circuit, part of them being pointed normally in each direction so that no matter in which direction wavesl are to be transmitted, only a part of the nepeater pointing circuits will have to be operated to put the entire system in operation.

The repeater circuit of this invention is of the biased type for transmission'in one direction and of the neutral type for transmission in the other direction so that it is well fitted for use in a transmission system in which the conditions are such that one type is best suitedfor transmission in one direction while the other type is desirable for transmission in the other direction. For example, it is well suited for connectingI a relatively quiet' line to a relatively noisy line in which case it is connected so as to normally transmit waves from the quiet line to the noisy line. s When used in thls manner, the signal operated circuit at the output of the repeater will not have to maint-ain so great a margin against amplilied noise.

. impresse in addition, un, @nena of this invention.

is very simple and requires only one amplifier and one delay circuit.

This invention can be more readily understood by reference to the following detailed description in connection with the drawing in which:

Fig. 1 shows diagrammatically one embodiment of the invention, and

Figs. 2 and 3 show two transmission systems employmg repeater circuits of the type shown in Fig. 1.

Referring .to Fig. 1, there is shown a repeater circuit having west terminals 4 and east terminals 5. There is provided a repeater or amplifier 6 which is preferably of the vacuum tube type. This amplifier is so connected to the

terminals

4 and 5 that transmission from west to east may take place without any change in the transmission circuit.

Relays

7 and 8 are provided for pointlng the repeater in the opposite direction when transmission from east to west is initiated. The windings of these relays are con-- nected to the output of an amplifier-rectifier 9, the input of which is connected to the terminals 5. rlhe operation of relay 7 also opens the input circuit of a second amplifier-rectiier 10 which has a relay 11 connected to its output circuit for opening the input circuit of the amplifier-rectifier 9 when transmission from west to east is taking place. A delay network 12 is connected between the terminals 5 and the contacts of relay 8 so that the transmission of waves from east to west is delayed until the

relays

8 and 7 have had suticient time to operate to point the ampliier 6 in the proper direction.' 'lhis network also delays the transmission from west to east for suiicient time to permit the operation of relay 11 to' open the circuitsupplying

relays

7 and 8.

" Thus', waves impressed on the west terminals 4 are directly transmitted through the aliiplier 6 and at the same time a portion of the energy impressed on the west terminals is transmitted through a separate circuit to energize the amplifier-rectier 10 to operate Vthe relay 11. The relay 11 opens the input circuit of the am liier-recter 9 so that it can not be energize by the amplifier waves in the out ut of the amplifier 6. Also, waves 'on the east terminals 5 energize the amplifier-rectifier 9 to operate

relays

7 and 8 repointing the amplifier 6 to transmit waves `from east to west and opening the input circuit of the amplifier-rectifier 1() so that it will not be affected by the amplified waves.

If any correcting networks or filters are required for transmission in both directions, p

they may be included as part of the amplifier circuit 6l unless they are of value as delay circuits in which case they should be inserted in place of or as a part of the network 12. If itis desired to transmit with unequal efliciency in the two directions, appropriate networks for. transmitting from westy to east may be inserted in the input leads 13 or the output leads 14, and appropriate networks for transmitting from east to west may be connected in the Ainput leads 15 or the output leads 16, as desired.

With the type of circuit described, no time is lost for transmission from west to east, but transmission in the opposite direction requires some time for operation of the relays. On the other hand, the

relays

7 and 8 normally connected to the output of the amplifier must maintain a margin against amplified noise, so that noise on the west line, amplified by the amplifier 6, will not operate them.

With regard to the time of operation, the disadvantages may be overcome in a transmission system by pointing alternate repeaters in opposite directions so that, for the system as a whole, transmission in either direction will only require the operation of one half of the repeaters. a noisy line is to be connected to a quiet line, a repeater of this type presents certain definite advantages as hereinafter described.

Fig. 2 shows a transmission system for transmitting between a station A and a station B. The system comprises a relatively quiet section of line 20 connectedbetween two relatively noisy sections of

lines

21 and 22.

Repeaters

23 and 24, which are the type shown in Fi 1, are connected between the line 20

andt e lines

21 and 22, respectively. As indicated, these repeaters are connected in such a Vway that transmission normally takes place from the quiet line to the -noisy lines and for transmission in the opposite direction they must be repointed.- In this way no strict 'requirements as to-margin againstamplified noise are placed upon the relays connected to the output of the amplifiers. The quiet line might, for example, be a section of submarine cable of such length or attenuationthat a sufiiciently accurate balance to obtain the necessary high gain with the standard type of repeater could not be provided.

Fig.'3 shows a similar system in which

repeaters

26 and 27 are connected between a noisy line 28 and two relatively

quiet lines

29 and 30, respectively. Inthis system, as indicated, the repeaters are so .connected as to normally transmit from the quiet lines to In situations in which.

, In the systems of both Figs. 2 and 3 transmission in either direction requires the operation of the printing circuit of only one reeater.

What is claimed is: f f

1. In a two-way signaling circuit, a oneway repeater normally connected to transmit waves in one direction, means responsive to waves in the other direction for pointing said repeater toamplify waves in that direction, and means responsive to waves being transmitted in said one direction for making said first means inoperative.

2. A combination according to the preceding claim, and a delay circuit common to a portion of said signaling circuit traversed by the waves transmitted in either direction therein, and located so as to prevent transmission of the waves in said one direction to the first mentioned means until the second mentioned means has operated, and to prevent transmission of the waves in said other direction to said repeater until the first mentioned means has operated.

3. In combination, a plurality of twoway l way repeater, and means for normally v connecting said repeater to transmit waves in one direction and for automatically pointing said repeater in the opposite direction in response to waves being transmitted in that direction, substantially half of said repeater circuits being connected so as to normally transmit waves in one direction and the remainder of said repeater circuits being connected so as tonormally transmit waves in the. opposite direction.

4. In combination, a relatively quiet twoway signaling line, a relatively noisy twoway signaling line, a one-way repeater connected between4 said lines and operative al,-

ways in the absence of signaling transmission in either direction in said lines, and for signaling transmission in the direction from said quiet line to said noisy line, to transmit waves from said quiet line to said noisy line andmeans for pointing said repeater in the opposite direction in response to signaling waves from said noisy line.

5. In combination, a pair of two-way transmission lines, a one-way repeaterA normally connected to transmit waves from one of said lines to the other, a relay responsive to waves from said other line for pointing said repeater in the opposite direction, and a second relay responsive to waves from said rst line for making said first relay inoperative, said second relay being made inoperative by the action of said first relay.

6.`A combination according to the preceding claimj in which a delay circuit is connected between the point in said other line to Which said first relay is connected and said repeater.

7. In a two-Way signaling circuit, a one- Way circuit normally connected to transmit Waves in one direction, means responsive to waves in the other direction for pointing said one-Way circuit to transmit Waves in that direction, and means responsive to Waves being transmitted in said one direction for making said first means inoperative.

8. In combination, a pair of two-Way transmission lines, a one-Way circuit normally one-Way circuit in the opposite direction, andv a second relay responsive to Waves from said one line for making the first mentioned relayu inoperative, said second relay being made inoperative by the action of said rst mentioned V relay.

In Witness whereof, I hereunto subscribe I my name this 29th day of December A. D. 1926.

HOIWER W. DIIDLEY. I