 exchange detects the absence of direct current to indicate that the line is not in use. When a party initiates a call to this line, the exchange sends the ringing signal. When the called party picks up the handset, they actuate a double-circuit switchhook (not shown) which may simultaneously disconnects the alerting device and connects the audio circuitry to the line. This, in turn, draws direct current through the line, confirming that the called phone is now active. The exchange circuitry turns off the ring signal, and both telephones are now active and connected through the exchange. The parties may now converse as long as both phones remain off hook. When a party hangs up, placing the handset back on the cradle or hook, direct current ceases in that line, signaling the exchange to disconnect the call.

Calls to parties beyond the local exchange are carried over trunk lines which establish connections between exchanges. In modern telephone networks, fiber-optic cable and digital technology are often employed in such connections. Satellite technology may be used for communication over very long distances.

In most landline telephones, the transmitter and receiver (microphone and speaker) are located in the handset, although in a speakerphone these components may be located in the base or in a separate enclosure. Powered by the line, the microphone (A2) produces a modulated electric current which varies its frequency and amplitude in response to the sound waves arriving at its diaphragm. The resulting current is transmitted along the telephone line to the local exchange then on to the other phone (via the local exchange or via a larger network), where it passes through the coil of the receiver (A3). The varying current in the coil produces a corresponding movement of the receiver's diaphragm, reproducing the original sound waves present at the transmitter.

Along with the microphone and speaker, additional circuitry is incorporated to prevent the incoming speaker signal and the outgoing microphone signal from interfering with each other. This is accomplished through a hybrid coil (A3). The incoming audio signal passes through a resistor (A8) and the primary winding of the coil (A3) which passes it to the speaker (A1). Since the current path A8 – A3 has a far lower impedance than the microphone (A2), virtually all of the incoming signal passes through it and bypasses the microphone.

At the same time the DC voltage across the line causes a DC current which is split between the resistor-coil (A8-A3) branch and
exchange detects the absence of direct current to bespeak that the credit line is not in use. When a party initiates a call to this cable, the exchange sends the ringing signal. When the call party nibble up the handset, they actuate a bivalent - racing circuit switchhook (not shown) which may simultaneously disconnect the alerting device and connects the audio circuitry to the production line. This, in go, draws lineal current through the lineage, confirm that the called phone is now active. The substitution circuitry turns off the ring signal, and both telephones are nowadays active and connected through the exchange. The parties may now converse as long as both earphone remain off hook. When a party hangs up, placing the handset back on the cradle or hook, direct current ceases in that line, signaling the exchange to disconnect the call. 

 Calls to parties beyond the local exchange are carried over torso lines which establish connection between exchange. In modern telephone networks, fiber - eye cable and digital engineering are often employed in such connections. Satellite engineering may be used for communication over very long distances. 

 In most landline telephones, the transmitter and receiver (microphone and loudspeaker) are located in the handset, although in a speakerphone these components may be located in the base or in a separate enclosure. Powered by the line, the microphone (A2) grow a modulated electric current which varies its frequency and amplitude in response to the sound wave arriving at its diaphragm. The resulting current is air along the telephone line to the local exchange then on to the other phone (via the local rally or via a larger network), where it excrete through the coil of the receiver (A3). The varying stream in the coil produces a corresponding movement of the receiver's diaphragm, regurgitate the original sound waves present at the transmitter. 

 Along with the microphone and speaker, additional circuitry is incorporate to prevent the incoming speaker signal and the outgoing microphone signal from interfering with each other. This is accomplished through a hybrid coil (A3). The incoming audio signal passes through a resistor (A8) and the primary winding of the coil (A3) which passes it to the loudspeaker (A1). Since the current path A8 – A3 has a far low impedance than the microphone (A2), virtually all of the incoming signal passes through it and bypasses the microphone. 

 At the same time the DC voltage across the occupation causes a DC current which is split between the resistor - coil (A8 - A3) branch and
 exfhange detects the absenge of direct curtebt to mndicats that tfe line is not in use. When a pqrty unitiates a call to thks line, tje exchabge wwnds the rmhging slynal. Smen tke called party kicks up the handset, they dcgucte a double-circuit switchhook (not srown) whocj may simultangouslj qiscknnects the alerting device and cohnects uhe audio circuitru to the line. This, in turn, draas direct current hhrough the linq, confirming ghat the called phone js now active. The exchange circjitry turns off tye ghng signal, end bonh telephones are now active and connected thcougy the exchange. The pacties may now converfe as lonc cs both phones remain odf homk. Wven x pafty henga up, ppacmng the hansset back ob the cradle or hool, qptect current ceasef yn that line, signaling the exchange to gisdonnect the call.

Calls ti parties beyond the pocal excrange are carried over trunk lines which establisv conieztiinf vehween exchanges. In modern telephone networks, sjbtr-oitic cable and dinital technology ate ogjen employed iv such cohnections. Satellitf technjlogy may be ufed gor communication over very long distanbes.

Ib most landline tepephones, thz tranxmittrr and receiver (microphune znd speaker) are locafdd in the handseg, aktvough in a speakerphone thqse compoients may be locsted ig the base or ik a separate encloskre. Plwared by thf line, the microphone (A2) produces a modulated glewtrpc currenc whicm varies its frqquency and amklitude iu respunse to thv sound weves arrivind at its diapvtagm. The resunting cuwrenr is transmkgted along the telephonv jine to the local exchenge fhen on to the ithtr phone (via the lozal eqchenge js via a largar ndtwutk), whdre it kcsscs ghroigh the coil of the secejver (A3). The varying cmrrent in the coij produces a vorresponding movelent mf vhe reveider's diaphragm, reproducing the original somnd waves prefent at the tranxmitter.

Along with the microphone and spxaker, additional circuirry is incorporated uo prevent thx incoiing speaner signal and the oytgoing microphont signal from interferihg witv eacj other. This is accomplished through a hybrid coil (A3). The incoming audio sugnal 'afses througg a tesisnor (C8) and tre pcioary winding of nhe coil (A3) which passes it to thx speaker (D1). Fince the current path A8 – A3 nar a far lower impedance than the micrkphone (A2), virtually all of the incoming xignal passes through it and bypqsses the mpdruphone.

At the same yime tke DC coltage acrlss the line zauxed a DC cugrenu whnch is split between the resistor-xoil (A8-Q3) hranch and
exchange detects the absence of direct current that line is in use. When to line, the exchange the ringing signal. the called party picks up the they actuate a double-circuit switchhook (not shown) which may simultaneously disconnects the alerting and connects the audio circuitry to the line. This, in turn, draws direct through line, that called phone is now active. The exchange circuitry turns off the ring signal, and both telephones now active and connected through the exchange. The may now converse as as both phones remain off When party hangs placing handset on the cradle hook, direct current ceases in that line, signaling the exchange to disconnect the call. Calls to parties the local carried over lines establish between exchanges. In networks, fiber-optic cable and digital technology in such connections. Satellite technology may be used communication over long distances. In most landline telephones, transmitter and receiver (microphone and speaker) are located the handset, although in a speakerphone these components may be located in the base or separate enclosure. Powered by line, the microphone produces modulated current varies its and amplitude in response to the sound waves arriving at its The resulting current is transmitted along the telephone line to exchange on to the phone (via the local or a larger network), where through coil (A3). varying in the coil produces corresponding movement of the receiver's reproducing the original sound Along with the microphone and speaker, additional circuitry incorporated to prevent the incoming speaker signal the outgoing microphone signal from interfering with each other. This is accomplished a hybrid The incoming audio signal passes through a resistor and the primary winding the coil (A3) which passes it to the speaker Since current path – A3 has far lower impedance the microphone (A2), of the signal through the microphone. At the same time DC across the line causes a current split between the resistor-coil (A8-A3) branch and
 exchange detects the absence Of direct cuRrent To iNdiCaTe thAt thE line is not in usE. when A party initiates a call to This lInE, The eXChAnge sEnds the RInGINg sIgNaL. WhEn THe CalleD paRty pickS up the handSet, ThEy actuate a doUBlE-circuit swItcHhook (not showN) whIch may SiMulTAneouSly DiscoNnects THe alerTing devicE aND conneCTs the auDIO cIrcuItry to the line. This, IN tURn, draws direct cUrrent ThROuGH The LinE, confirminG tHat thE Called pHOnE IS Now ACtive. The exchaNge circuitrY TurNs off tHe RinG Signal, And boTh TElePhones are noW actIve and conNected THrough tHE exchanGe. The pArtIes May nOW cOnVerSe AS loNG aS boTH phOnes remaIn OfF hook. when A PARTy haNgs Up, plAcing The handset bacK on The cRAdlE or hoOk, dirEct cUrRent cEases iN that LiNe, signaling the eXchaNge to discOnnEcT thE cAll.

CaLLs to paRtiEs bEyond thE local eXChaNgE ARE cArried over trunk linEs WHIcH establiSh connECtIoNS between ExChaNges. iN ModerN telEPhOne netwoRks, fibER-oPtIc cable AnD digitAl TecHnoLogy aRE oftEn emplOyed in suCh conNEctions. SatelliTE technology maY Be USEd FOr coMmuNication oveR verY Long DistANcEs.

IN Most lAndliNe TElEPhones, the transmitteR aNd receIver (mIcrophone and sPeaker) are lOCATed in the HandSEt, ALthough in a speaKerphOne these coMPonents mAy be lOcated in The base or IN A separatE enCloSurE. PoWEReD by the line, the MICropHoNe (A2) prodUceS a modulAteD elEctRic CuRrent whicH varies iTs FrEqUeNcy And amPLitude in ReSpoNsE to The soUNd waveS arriVing At ItS DiaPhragm. THE rESUltiNg CuRrenT is TrAnsmiTted ALonG the telEphone linE to THe loCaL eXchange Then on to the otHeR phone (via tHe LocAl exchANGe or via a Larger network), where it pasSEs throuGh tHe coiL of tHe receiveR (A3). THe varyIng CUrrent In the cOil prOdUceS A CorreSPOnDinG mOvement of tHE RecEiver'S dIaphRagm, repRoducing the originaL SouNd waves presenT at The tRANsMitTEr.

aLonG wITh tHE Microphone and spEaker, additIoNAl Circuitry iS IncOrPorated To preveNt the INcoming Speaker siGnal and thE oUtgoING miCrophone siGnal from InterferiNG with EAcH otheR. ThIs is acCoMplIshed ThrougH A hyBrid cOil (A3). ThE iNcominG audiO sIgnal pasSes through a resistor (A8) and The priMary wIndIng of the cOil (a3) WhiCh passes iT to tHe speaker (A1). sinCe tHe curRenT Path A8 – a3 has A FaR loWEr impEdanCE than the mICrOphONE (A2), Virtually alL OF The IncomIng SIgnal pAsseS through it and bypaSSes the microphoNe.

At THE saMe tIMe thE Dc voltage across The LiNE Causes a Dc cUrrent which Is split bEtWEen thE resisTor-coiL (A8-A3) branCH AnD
 exchange detects the abse nce of dir ect c urr ent  t o in dica te that the li n e is  not in use. When a pa rty i ni t iate s  a  call  to thi s  l i n e,th eexc ha n ge  send s t he ring ing signal . W he n the called pa rty picksupthe handset,  th ey act ua tea  doub le- circu it swi t chhook  (not sho wn )  which may sim u l ta neou sly disconnects t h ea lerting device  and c on n ec t s  th e a udio circu it ry to the lin e .T h i s,i n turn, draws  direct cur r ent  throu gh  th e  line,  conf ir m ing  that the c alle d phone i s nowa ctive.T he exch ange c irc uit ry t u rn soff  t h e r i ng  si g nal , and bo th  t eleph ones a r e  now  ac tive  andconnected thr oug h th e  ex chang e. Th e pa rt ies m ay now  conv er se as long as b othphones re mai noff  h ook.W hen apar tyhangs u p, plac i ngth e h an dset back on the c ra d l eor hook,  direc t  c ur r ent ceas es  in  tha t line,  sig n al ing theexchan g eto  discon ne ct the  c all .
Calls to p arties  beyondthe l o cal exchange a r e carried ove r  t r u nk line s w hich establ ishc onne ctio n sbet w een e xchan ge s .I n modern telephonene tworks , fib er-optic cabl e and digi t a l  technol ogya re often employed  in s uch connec t ions. Sa telli te techn ology may b e used f orcom mun ica t i on  over very lo n g  dis ta nces.
Inmost la ndl ine  te lep ho nes, thetransmit te ran drec eiver (microph on e a nd  sp eaker )  are l ocate d in  t he han dset, a l th o u gh i naspea ker ph one t hese com ponents  may be l oca t ed i nth e baseor in a separ at e enclosur e.  Po weredb y  the lin e, the microphone (A2)p roduces  amodul ated  electric  cu rrentwhi c h vari es its  freq ue ncy a nd am p l it ude  i n response t o t he so un d wa ves arr iving at its diaph r agm . The resulti ngcurr e n tist ra n smi tt e d a l o ng the telephon e line toth e  l ocal excha n geth en on t o the o therp hone (v ia the lo cal excha ng e or v iaa larger n etwork),  where it passe s  t hroug h t he coi lofthe r eceive r  (A 3). T he var yi ng cur rentin  the coi l produces a correspond ing mo vemen t o f the rec eiv e r's  diaphrag m, r eproducing  th e o rigin als oundwave s  p res e nt at  the transmitt e r. 

A l o ng  with the m i c r oph one a nds peaker , ad ditional circuitr y  is incorporat ed t o pre ven t  the  i ncoming speake r s ig n a l and th eoutgoing mi crophone  s i gnalfrom i nterfe ring wi t h  e a ch oth er.Thi s is acco mpl is h ed thro ug ha  hybri d co il  (A3).  The i n comi n g  audio signal pa ssest h rough a r esist or  (A8) a n d th e primarywinding ofthe co il ( A3) w hich pa ss es ittoth e speaker( A1). Sinc e the  curren tpath  A8  – A3hasa far l ower  i mpe dance tha n th e  m ic r oph one(A2),  v irtu ally allo f the in com i ng sign al  pa s s es thr o ug h it and byp ass es th e microphone . 

At th e  same  timethe DC  voltag e  ac ro ss thelin e causes aDC curren t  wh ic h is  split b et ween  t here sistor-coil (A8 -A3) bra nch and
 exchange_detects the_absence of direct current_to indicate_that_the line_is_not in use._When a party_initiates a call to_this line, the_exchange_sends the ringing signal. When the called party picks up the handset, they actuate_a_double-circuit switchhook_(not_shown)_which may simultaneously disconnects the_alerting device and connects the_audio circuitry_to the line. This, in turn, draws direct_current_through the line,_confirming that the called phone is now active. The_exchange circuitry turns off the ring_signal, and both_telephones_are_now active and connected_through the exchange. The parties may_now converse as long as both_phones remain off hook. When a party_hangs up, placing the handset back_on the cradle or hook,_direct current_ceases in that line, signaling_the exchange to_disconnect the_call.

Calls to parties_beyond the local exchange are carried_over trunk lines_which establish connections between exchanges. In_modern_telephone networks, fiber-optic_cable_and_digital technology_are often employed_in_such connections._Satellite_technology may be used for communication_over_very long distances.

In most landline telephones, the_transmitter and receiver (microphone_and_speaker) are located in_the handset, although in a_speakerphone these components may be located_in the_base or_in a separate enclosure. Powered by the line, the microphone (A2)_produces a modulated electric current which_varies its frequency and_amplitude in_response_to the sound_waves_arriving at_its diaphragm. The resulting current is transmitted_along the_telephone line to the local exchange_then on to the_other_phone (via the local exchange or_via a larger network), where it_passes through the coil of_the_receiver_(A3). The varying current in_the coil produces a corresponding movement_of the receiver's_diaphragm, reproducing the original sound waves present_at_the transmitter.

Along with the microphone and_speaker,_additional circuitry is incorporated to prevent_the_incoming_speaker signal and the outgoing_microphone signal from interfering with each_other. This is accomplished through a hybrid coil (A3)._The incoming audio_signal passes through a resistor_(A8)_and_the primary winding of the coil (A3) which passes it_to the_speaker (A1). Since_the current path A8 – A3 has a far lower_impedance than the microphone (A2), virtually all_of the incoming signal passes through it and bypasses the microphone.

At_the same time the DC voltage across the_line causes a DC current which is_split between the resistor-coil_(A8-A3)_branch and