US1545558A - Tandem-operated echo suppressor - Google Patents

Tandem-operated echo suppressor Download PDF

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Publication number
US1545558A
US1545558A US723796A US72379624A US1545558A US 1545558 A US1545558 A US 1545558A US 723796 A US723796 A US 723796A US 72379624 A US72379624 A US 72379624A US 1545558 A US1545558 A US 1545558A
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US
United States
Prior art keywords
circuit
echo
wire
circuits
tandem
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US723796A
Other languages
English (en)
Inventor
Harold S Hamilton
Sumner B Wright
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
AT&T Corp
Original Assignee
American Telephone and Telegraph Co Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by American Telephone and Telegraph Co Inc filed Critical American Telephone and Telegraph Co Inc
Priority to US723796A priority Critical patent/US1545558A/en
Application granted granted Critical
Publication of US1545558A publication Critical patent/US1545558A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B3/00—Line transmission systems
    • H04B3/02—Details
    • H04B3/20—Reducing echo effects or singing; Opening or closing transmitting path; Conditioning for transmission in one direction or the other
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B3/00—Line transmission systems
    • H04B3/02—Details
    • H04B3/04—Control of transmission; Equalising
    • H04B3/10—Control of transmission; Equalising by pilot signal

Definitions

  • rho oiiieeis of the invention is to an urmingcine wherebytwo or ch eo pod with echo supa l a M rod in tandem.
  • .u four-wire circuit is schematically shown, said circuit being equipped with the usual one-way repeaters and :in colic suppressor between stations X and Y, while a similar circuit is shownbeiween stations Y and Z for terminal connections over either circuit.
  • Each individual echo suppressor functionsiu its normal manner, th at is,-wlien transmission takes place "from X to Y the .XY suppressor operates and short circuits" the opposite branch of the four-wire circuit, suppressing echoes from Y, and ice verse.
  • Fig. 2 shows schematically an arrangement for obviating this difi iculty by making both suppressor units associated with one of the four-wire circuits inoperative when the two circuits are connected together in tandem.
  • the operators through toll cord circuit is shown at Y between thetwo four-wide circuits.
  • This toll cord is arranged so that when all four of its plugs are inserted in the. line and network jacks by which the four-wire circuits are terminated at station Y. the line terminals of the four-wire circuits as well as the network terminals will be directly connected together.
  • Relays B ll, and G are operated as shown so that positive battery C, is applied to the right-hand core simplex D
  • the relay F upon being energized, closes the control wire (which may be a simplex or composite circuit of any well known type if desired) at one point, but the energization of the polar relay G, opens the control Wire at another point so that the circuit of the relay H at the echo suppressor is not closed and consequently the two units of the echo suppressor remain in their normal condition.
  • the right-hand cords at office Y are then inserted in the Y-Z circuit.
  • Current flows from positive battery G over the contact of relay 13,, through simplex l'). derived from re aeating coil L, over the line plug and jack terminals to simplex E and thence through neutral relay F, and polar relay G to grormd.
  • This current-is of opposite polarity from the current flowing through the left line cord anc operates the neutral relay F, but does not peratc the polar relay G Consequently, ground is connected to the masses Y-Z control wire so that current from battery J in the echo suppressor flows through and operates the relay H thereby opening the short-circuiting connections controlled by the two units of the echo suppressor.
  • the two echo suppressor units associated with the Y-Z circuit are. therefore disabled and the built-up circuit is then complete with only the XY suppressor functioning.
  • both relays F and G would be operated without affecting the control wire to the relay H so that the echo suppressor units windings associated with the tour-wire circuit between office Y and office Z would be permitted to function normally.
  • a circuit would be completed from positive battery 0 over' the .front contact of relav Ba. over the simplex i in tifieial line ei'mneci-ious.
  • the tuniim eomrse" -11 between the two fourmzire circuits shown in i i $3 may be extended from office i0 :inomer office at for reieys B ii end the left of biz usiizs' another throu h toll cor-d circuit; at X equipped simili .iy to tiisi; shown. at Y. in this ease the network N Wiii be (iiseoimeeteii irom the hybrid eoii at office X and the hyhrid soil. connected to a network jack :iil o manner similar to that shown at office Y.
  • a transmission system e plurality of transmission circuits ziflap eci. to he-eon-. necked in tandem, a. pair of eeho suppressor units associated with, each cirouiii, one unit llCv being; responsive toheurrent-s transmitted in one direction. to disable the circuit for 'i-lfil'lS-z mission in the opposife il'iIEiGiJiOil and the tandem. to render all of the eel f ressor uni-s u eiieotive e iteeloi xiii mi t,$i%ifi$6(i with oiz e fm i T &0
  • a transmission system a plurality of transmission circuits adapted to be connected in tandem, a pair of echo suppressor units associated With each circuit, one unit being responsive to currents transmitted in one direction to disable thecircuit for transmission in the opposite direction and the other unit being responsive to currents transmitted in the opposite direction for disabling the circuit for transmission in said first direction, means for connecting said transmission circuits in tandem, and circuits con trolled by said means for rendering all of the echo suppressor units ineffective except the pair associated with one of said transmission circuits.
  • a transmission system a plurality of transmission circuits adapted to be con.- nected in tandem, a pair of echo suppressor units associatedwith each circuit, one unit being responsive to currents transmitted in one direction to disable the circuit for transmission in the opposite direction and the other unit being responsive to currents transmitted in the opposite direction for dis abling the circuit for transmission in said first direction, and a cord circuit for interconnecting a pair of said transmission circuits in tandem, and means associated with said cord circuit for rendering the'pair of echo suppressor units associated with one of said transmission circuits ineffective.
  • a transmission system a plurality of transmission circuits adapted to be connected in tandem, a pair of echo suppressor units associated with each circuit, one unit being responsive to currents transmitted in one direction to disable the circuit for transmission in the opposite direction and the other unit being responsive to currents transmitted in the opposite direction for disabling the ircuit for transmission in said first direcwhereby the pair of echo suppressor uuits-associated with either of the connected transmission circuits may be rendered ineffective while leaving the other pair in operative condition.
  • a transmission system a plurality of transmission circuits adapted to be connected in tandem.
  • a pair of echo suppressor units associated with eaclicircuit one unit being responsive to currents transmitted in one direction to disable the circuit for transmission in the opposite direction and the other unit being responsive to currents transmitted in the opposite direction for disabling the circuit for transmission in said first direction
  • a, cord circuit for connecting a pair of said ti nsmission circuits in tandem, and controling circuits associated with said cord ,circuit for rendering the pair of echo suppressor units'associated with either of said transmission circuits inoperative, said controlling circuits being so arranged that When the cord circuit is connected to one of said transmission circuits it will not afi'ect the echo suppressor units associated therewith but when connected to the other transmission circuit the pair of echo suppressor units associated therewith Will be rendered ineffective.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
US723796A 1924-07-02 1924-07-02 Tandem-operated echo suppressor Expired - Lifetime US1545558A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US723796A US1545558A (en) 1924-07-02 1924-07-02 Tandem-operated echo suppressor

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US723796A US1545558A (en) 1924-07-02 1924-07-02 Tandem-operated echo suppressor
GB27117/24A GB245554A (en) 1924-11-13 1924-11-13 Improvements in or relating to telephone repeater circuits

Publications (1)

Publication Number Publication Date
US1545558A true US1545558A (en) 1925-07-14

Family

ID=10254473

Family Applications (2)

Application Number Title Priority Date Filing Date
US723796A Expired - Lifetime US1545558A (en) 1924-07-02 1924-07-02 Tandem-operated echo suppressor
US723802A Expired - Lifetime US1545541A (en) 1924-07-02 1924-07-02 Tandem-operated echo suppressor

Family Applications After (1)

Application Number Title Priority Date Filing Date
US723802A Expired - Lifetime US1545541A (en) 1924-07-02 1924-07-02 Tandem-operated echo suppressor

Country Status (6)

Country Link
US (2) US1545558A (cs)
CH (1) CH113647A (cs)
DE (1) DE474670C (cs)
FR (1) FR596065A (cs)
GB (1) GB245554A (cs)
NL (1) NL15798C (cs)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2990457A (en) * 1958-02-04 1961-06-27 Bell Telephone Labor Inc Tandem echo suppressor circuits

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2990457A (en) * 1958-02-04 1961-06-27 Bell Telephone Labor Inc Tandem echo suppressor circuits

Also Published As

Publication number Publication date
FR596065A (fr) 1925-10-15
NL15798C (cs) 1927-01-15
US1545541A (en) 1925-07-14
CH113647A (fr) 1926-02-16
DE474670C (de) 1929-04-12
GB245554A (en) 1926-01-14

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