Telephone

Synonymtelephone(equipmentthattransmitsvoiceinbothdirectionsthroughelectricalsignals)generallyreferstotelephones.

Basicstructure

CombinedAtlas(2photos)

PhoneThemachineisaterminaldevicethattransmitsvoiceinbothdirectionsthroughelectricalsignals.

Historicalimprovementsandinventionstotelephonesinclude:tonermicrophones,manualtelephoneexchangeboards,dials,automatictelephoneexchanges,program-controlledtelephoneexchanges,dual-tonemulti-frequencydialing,voicedigitalsampling,etc.Newtechnologiesinclude:ISDN,DSL,analogmobilephonesanddigitalmobilephones.

Basicbuttons

Telephonepowercord,telephoneline,take-upswitch,receiver,boosterbutton,transmitter,localnumberchip,ringtoneAndhands-freespeaker,memorycodekey,memorynumberpiece,numberkey,memoryretrievalkey,memorystoragekey,redialkey,workindicator,hands-freekey,Rkey,hands-freemicrophone,ringtoneadjustmentswitch,P/Tswitch,hands-freereceivingvolumeadjustmentknob.

Workingprinciple

Telephonecommunicationisacommunicationtechnologythatusesthemediumof"electricity"totransmitlanguagethroughthemutualconversionofsoundenergyandelectricenergy.Tocommunicatebetweentwousers,thesimplestformistoconnecttwotelephoneswithapairoflines.

Whenthecallerpicksupthetelephoneandspeakstothemicrophone,thevibrationofthevocalcordsexcitestheairtovibrate,formingsoundwaves.

Soundwavesactonthemicrophonetogeneratecurrent,whichiscalledvoicecurrent.

Thevoicecurrentistransmittedalongthelinetothereceiveroftheotherparty'sphone.

Thefunctionofthereceiverisjusttheoppositeofthatofthemicrophone-itconvertstheelectriccurrentintosoundwaves,whicharetransmittedtotheearsthroughtheair.

Inthisway,thesimplestcallprocessiscompleted.

DevelopmentHistory

ThetelephonewasinventedbyAmericanA.G.Bellin1876.Heusedtwowirestoconnecttwotransmittersandreceiverswiththesamestructureandequippedwithavibratingdiaphragmontheelectromagnet,andfirstlyrealizedthecallbetweenthetwoends.Butthecommunicationdistanceisshortandtheefficiencyislow.Charcoalmicrophonesappearedin1878,whichgreatlyimprovedtheefficiencyoftelephonemicrophones.Thereceiverstructurehasalsobeenimproved.Theearliesttelephonewasamagnettelephone,whichwaspoweredbyitsownbatteryandusedahand-crankedgeneratortosendcallsignals.In1880,acommonpowertelephoneappeared,andthepowersupplywascentralizedbyacommonpowerswitch,eliminatingtheneedforhand-broadcastgeneratorsanddrybatteries.In1891,arotarydialtypeautomatictelephoneappeared,whichcansendoutDCdialpulses,controltheactionoftheautomaticswitch,selectthecalleduser,andautomaticallycompletetheswitchingfunction.Therebypushingthetelephonecommunicationtoanewstage.Bytheendofthe1960s,apush-buttonfullelectronictelephoneappeared.Inadditiontothepulsenumberingmethod,dual-tonemulti-frequency(DTMF)numberingmethodhasappeared.Withthedevelopmentofprogram-controlledexchanges,dual-tonekeytelephoneshavegraduallybecomepopular.Electronictelephonecircuitsaremovingtowardsintegration,andtelephonespecificintegratedcircuitshavebeenwidelyusedinvariouscomponentsoftelephonecircuits.Variousmulti-functiontelephonesandspecialpurposetelephoneshavealsoemerged.Bytheearly1990s,thereweretelephonesthatintegratedthethreefunctionsofdialing,talking,andringingonasingleintegratedcircuit.Withthedevelopmentofvoicerecognitiontechnology,newtypesoftelephonesthatdirectlyusevoiceto"dial"arealsoemerging.

Theoriginaltelephone(terminal)wasamagnet-typetelephoneconsistingofamicrogeneratorandabattery.Whenmakingacall,theusercrankedthemicrogeneratortosendoutanelectricalsignaltocalltheotherparty.AftertheotherpartystartedthephoneFormacallloop.Later,in1877,afterT.E.Edisoninventedthecarbonmicrophoneandtheinductionline,thecommunicationdistancewasextended.Inthesameyear,thepublictelephonewasinvented.In1891,itfinallydevelopeduntilA.B.Strowgerinventedtheautomatictelephone.

Basicfunctions

Thetelephoneissetontheusersideatthestartandendoftelephonecommunication,andistheuserterminalequipmentofthetelephonenetwork.Moderntelephonescanconvenientlyrealizecallsandconversationsbetweenterminalusers,whichareformedaftermorethanonehundredyearsofresearchandcountlessimprovementsbymanypeople.Althoughtheirstylesareverydifferent,theygenerallyhavethefollowingbasicfunctions:

1,audio-electricalinterchange

Becauseoftheneedforfastandlong-distanceCommunicationcannotdirectlytransmitsound,butmustfirstturnthesoundintoanelectricsignal(thatis,useelectricityasacarrier),andthenrestoretheelectricsignaltosoundafterreachingtheotherparty.

2.Off-hookrecognition

Whenthecallerpicksupthephone,theexchangeshouldbeabletoknow"someonewantstomakeacall"function,Sothattheswitchisreadyforconnection.

3.Sendingsignals

Theautomatictelephonesetsdirecttheworkofthetelephoneexchangebysendingdial-upsignals,andthenestablishesaconnectionbetweenthetwotelephonesets.Connected.

4.Ringing

Whentheotherpartycalls,thephonecantelltheownerwitharingtone:"Someoneiscalling."

5.Electricalconnection

Inthetelephone,thecomponentsthatrealizethesefivefunctionsare:transmitterandreceiver,hookswitch,dial(orkeyboard),telephoneRingandtelephoneloop.

Maincategories

Wiredtelephone

Thetelephonehasthefunctionofconvertingthesoundwaveoftheterminalintoanelectronicsignal,whichistransmittedtotheremotepartythroughthetelephoneline,andatthesametime,theotherpartyThetransmittedelectronicsignalisregeneratedintovoice(soundwave)tomakeacall,anditsendsasignal(dialpulse)thatcanbeselectedfrommultipleparties,andfunctionstoinformtheotherpartyofthecallingtone.Thetelephoneconsistsofatransmitterthatconvertsvoiceintocurrentandsendsittothetelephoneline,areceiverthatrestoresthecurrenttransmittedbytheotherpartytovoice,dialsorbuttonstocalltheotherparty,andsendstheringingtoneofthecallingtone,andconnectsthesetothetelephonelineforexecution.Itsfunctionalcircuitnetworkandothercomponents.Thereisasmallboxfullofcarbonparticlesinthetransmitter,andthereisathinduraluminalloyvibratingplateinfrontofit.Thevibratingplatevibratesaccordingtothevoice,vibratingthecarbonparticles,andthecarbonparticlesconductcurrent.Withthecontactdegreeoftheparticles,theresistancechangestogenerateavoicecurrent.Afterthereceiverreceivesthevoicecurrentoftheotherparty,themagneticforcecausedbythevoicecurrentisgeneratedonthecoil,andtheironvibrationplateisvibratedtomakeasound.

Cordlessphone

Wirelessloop-cordlessphone

Phonehandset

Digitalcordlessphone

AnalogCordlessphone

Mobilephonehandset

PHS(wirelessphone)

Smartphone

WiththecontinuousrapiddevelopmentofITtechnology,Theprocessingpowerofembeddedterminalequipmentisgettingstrongerandstronger.Atthebeginningofthe21stcentury,a"smartphone"withapersonaldataassistant(PDA)phoneappeared.

Inadditiontocompletefixed-linephonefunctions,smartphonesusuallyalsohavelarge-capacitybusinesscardmanagementfunctions,incomingandoutgoingcallmanagementfunctions,preventionofphone)Managementfunctions,aswellasmanyfunctionsofauxiliaryoffice,suchas:schedule,memo,calendar,calculatorandotherfunctions.Earlysmartphonesuseddial-upaccesstotheInternet,whichhadacertaininformationexchangecapability,andrealizedthefunctionsofsendingshortmessagesandreceivingtextmessages.Withthedevelopmentoffixed-linesmartphonesinChinafornearlyadecade,theirprocessingcapabilitieshavebeenstrengthened,andthefunctionsofsmartphoneshavegraduallyincreased.

SmartphoneshavetheabilitytoaccesstheInternetviatheInternetandhavestrongmultimediafunctions.ItcanbrowsetheInternet,playaudioandvideo,andhavefunctionssuchase-booksandelectronicphotoframes.Atthesametime,thefunctionsofsmartphonesinassistingoffice,assistingmarketing,andentertainmenthavealsobeengreatlyenhanced.Onthebasisofoverturningtraditionalfixedtelephones,morebusinessfunctionsandPDAfunctionshavebeenrealized.

Useenvironment

Useconditions

Environmenttemperature:-10℃~40℃

Relativehumidity:45%~95%

Atmosphericpressure:860~1060mbar

Environmentalnoise:≤60dB(A)

Technicalperformance

1.Workingfrequency:300~3400HZ

2,pulseon-offratio:1.6±0.2:1

3,dualtonedialfrequencyoffset:≤±1.5%

4,dualtoneSignallevel:①Lowfrequencygroup:-9±3dB;②Highfrequencygroup:-7±3dB;③Thehighfrequencycomponentinthefrequencycombinationis2±1dBhigherthanthelowfrequencycomponent

5,theringtonelevel:≥70dB(A)

6.Electroacousticperformance:

①At0km,objectivetransmissionreferenceequivalent≥+3;at3kilometers,objectivetransmissionreferenceequivalent≤+15;At5kilometers,theobjectivetransmissionreferenceequivalentis≤+15.

②At0kilometers,theobjectivereceivingreferenceequivalentis≥-5;at3kilometers,theobjectivereceivingreferenceequivalentis≤+2;at5kilometers,theobjectivereceivingreferenceequivalentis≤+2.

③At0kilometers,theobjectivesidetonereferenceequivalentis≥+3;at3kilometers,theobjectivesidetonereferenceequivalentis≥+10;at5kilometers,theobjectivesidetonereferenceequivalentis≥+10.

Futuredevelopment

Thedevelopmentofhigh-techtelephonesisformedwiththedevelopmentofwirelesscommunication.ThedevelopmenttrendoftelephoneshasevolvedtoIMT-200servicesthatcanusesatellitecommunicationsafterDigitaltelephonesandPCS.IMT-200supportshigh-speedtransmissionofinformation,packet,imageandothermultimediaservices.Inthefuture,allvoicephones,directcircuitsfortelegramusers,pagingande-mailwillbeavailableeverywhereintheworld.Withthepopularityofe-mail,thenetworkisbecomingmoreandmore.Internettelephonyisanunstoppabledevelopmenttrend.Theexistingfixedtelephonescannolongerprovidepeople'sneeds.Inthefuture,fixed-linetelephoneswillbeequippedwithcamerasandcoloredliquidcrystaldisplays.Whenwereceivefixed-linetelephones,wecanseebothsides.

Related Articles
TOP