Western Electric Co., Incorporated, Engineerir^ 35ept«, Nev; York* iflETHOD OF OPBRATIOK TRUNK CIRCUIT Two Way - Ayrar^ged For Oross-Corjnection - To miscellaneous At « Special “A“ Board - Full Hechanical avitchirxg System. (3 Pages) Page #1. Issue ir2 BT'-431220* April 8 , 1921, Answering Jack And Lamp GENERiiL BESCRIPTIOH 1, This twO'Hvay trunk circuit is used to hanAle traffic between a special “A'* position and a Stromberg-Oarlson exchange* It is also used for conpletirxg calls o ^,r/3v. trsanivsi tant^e^T positions to a 3 Car Ison exchanCQ* Zt On :in inootnizig call from Stromber^Carlson exchange the line lamp liglits at the special A board, Waen the plug of an ansv/erir.g cord is inserted in the asso- ciated answering jack, the line lamp is extinguished and the talking circuit is closed# S. .aen tne plvg of ?. jaaiing oora or a Eanoal tandem c<M multiple jack at tfce special, A board, the line lamp lights at the otrombei^ -H exchange . 4. Standard supervision is given both operators by reversirg; the tip and g circuits between the two ends^ DETAILED DESCRIPTION OPERATION 5 . On an incomir^ call from a S*romberg-Carlson exchange B/,® ^ placing be,ttery on the sleeve lead of the multiple jacks relay. When and lighting the line lamp at the A board under oontro o , ; , limited the pl^ of an answering cord Is inserted in the jack af ^ 0-1 rfla^ ' line 1^ the CO relay operates, in turn operatir^ the rel^. operated releases tlie B relay and operates the OI-l o^f-^es, in tL line lar^. It also closes - srp^^/^e^ersTsIhr^olarity tufcn operating the 3-1 rel^. The operc-tion Av,r>niie'h the windirxps of of the battery to the tip and rir,g of toard frfflo lighting, tho A relay te prevent the supervisory l^P at the coruiect- and opens the circuit through the audible ringing sieU^l ’"'“l releas-, ion is taken down at the Stromberg-Carlson exobango, tte ^ ^ iug the S-1 relay ivhich battery to the answering cord through the mnd^r^s ‘ ^ .Xp^ of the cord is removed at tte “A- board as a discoruiect oS rated relays and from the answering jack at the special A board, releasx.^ all oieiat rcstorir^ the circuit to normal. m ■ • cr.'vpr-ial '‘A’ board, the release 6. In case discorxxotion originates at from the of the CO relay relsases the Cl relay, '^^®«°™®X^^?f„^^P^f/^hrsupervisory lamp rir.g and tip of the line respectively ana thereoy lightings the supervi cry at the otrcmberg-Carlson board as a discoriuect signal* (3 Ps^es) Page #2, Issue #2 - BT-431220. April 6, 1920* V* './lien the plug of a special A callir^ cord or a nianual tandem cord is in- serted in a luultiple jack at tls special A hoard, the calling cord supervisory lamp lights and the A relay operates, operating the 01 relay* The operation of tie 01 relay closes the tip and ring fciirough the repeating coil, lighting the line laij) at tlie Stromherg-Carlson ezchar^e, and operates the CI-1 relay which connects the audit le ringing signal lead to the tip of the line sending a ririglng tone back to the calling subscriber* VJhen the call is answered at the Strauberg-Garlson e^:- cliar^e the line lamp is extinguished and the S -relay operates, operatirig the b-1 relay v/hich opens the circuit through the audible ringing signal lead, and reverses the polarity of the battery flowing to the calling cord through the windings of tlB A relay, extinguisliing tiB cord supervisory lamp* VJhen tlie connection is talcen dov/n at tiie Btromberg-Carlson exclaange the supervisory lamp lights as a disconnect sig- nal, wlierer^on tlB plug Is removed from the multiple jack at the Special A board, . restoring the circuit to normal# If the plug of the cord is withdravvn first at the special “A" board the A relay releases, in turn releasing the Cl relay 'which causes the s’u^jervisory lamp at the Stromberg-Carlson board to light as a disconnect signal* B1 S V BIO C,0* B71 A E216 Cl Spl.B relay per ]>*22637 ® opliS per ]>-14961 3-1 #178-AQ CI-1 EInG » — HB H-RV • 7/16/21. ( SPages) Page #3, Is STUB #2 -* Bl!>-431220* April 8, 1920. CIRCUIT BEGUIREIvSHTS OPERATE KON-GPERATE After a soak of approx- isoately ,3 Amp, Test .OIS Amp. Ee-Adj. *016 Amp. After ^ soak of approximately ,3 Amp. Test .003 Aiip. Re-Ad j. .005 Amp. Test ,023 Amp* Re-Ad j. .022 Amp. Test #007 Amp. Re-Ad j. *002 Amp. Test .0019 Amp. Re-Ad j. .002 Amp. Test .0006 A 2 np* Re-Ad j. .0006 Amp* Test *029 Amp. Re-Ad j. .021 Amp. Test .014 Amp. Re-Ad J. .015 Anp. Test .0015 Amp. Re-Ad j. .0014 Amp. Test .040 Amp. Re-Ad^. .025 Amp. Test .045 Amp. Re-Ad j. .030 Amp. Test .0007 Amp. Re-Ad j. .0007 Amp. Test .0047 Amp. Re-Ado* *005 Amp. Test *0019 Amp. Re-Adj. .002 Amp. CHK*I).— EGL, APPROVED ClX. SIUYTEB, G.H.D.