WEBVTT

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In 1832, matematicianul Carl Grauss

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si profesorul de fizica Wilhelm Weber

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au creat un sistem 
care le permitea sa comunice

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de la distanta in timp ce desfasurau experimente -

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conectand observatorul cu laboratorul de fizica.

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Ei au rezolvat o problema foarte importanta,

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care era mai mult o enigma:

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cum sa transmita toate literele alfabetului

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folosind un circuit - sau o linie.

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Iar sistemul lor folosea un galvanometru

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deoarece se stia ca curentul electric, 
trecand printr-o

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bobina, creaza un camp magnetic 
care strabate

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centrul spirei, putand devia un ac.

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Dar in loc sa miste pur si simplu un ac
de la distanta

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sistemul lor a folosit un comutator

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care ar putea sa inverseze instantaneu
directia curentului.

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Acest lucru ar determina inversarea

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campului magnetic din jurul bobinei,

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iar acul ar devia fie la dreapta, fie la stanga

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in functie de directia curentului --

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oferindu-le astfel doua evenimente
de semnalizare diferite --

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sau "simboluri" -- deviere la dreapta sau la stanga.

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Cel mai important, el a atribuit simboluri

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mai scurte pentru literele cele mai obisnuite.

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[De exemplu], 'A' a fost o deviere unica
la dreapta

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Iar 'E' a fost o deviere unica
la stanga.

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Si a folosit codurile mai lungi
pentru literele mai putin folosite,

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cum ar fi 'K', care a constat in trei
devieri la dreapta.

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Si in acel moment, viteza de transmisie

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era in jur de noua litere pe minut.

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Toate acele de telegraf care au urmat

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aveau aceeasi limitare --

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si aceasta consta intr-o problema
de inginerie.

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"Viteza de semnalizare" era redusa.

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Acum viteza de semnalizare consta in

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numarul de devieri pe minut

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care puteau fi transmise si receptionate
cu precizie.

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Si daca se comprimau laolalta 
evenimentele de semnalizare

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persoana care receptioneaza ar fi fost 
confuza din cauza variatiilor rapide

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care produc erori --

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la fel cum notele cantate la un pian
in mod sustinut se vor imbina

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si vor deveni mai putin distincte --
daca sunt cantate rapid.

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Si, in timp viteza de semnalizare

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a fost imbunatatita incremental.

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Una dintre imbunatatiri a constat
in adaugarea unui magnet

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permanent de mici dimensiuni
la partea exterioara a bobinei.

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Acest lucru a contribuit
la retragerea acului inapoi

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in pozitia neutra,
dupa fiecare deviere.

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Si aceste modele au stat la baza
unei game largi de

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ace de telegraf, care au fost instalate
in intreaga Europa.

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Compania de telegraf electric

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a fost prima companie 
de telegraf publica.

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A fost creata in 1846, dupa ce proprietarii
au achizitionat

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principalele brevete de telegraf cu ac
de la acea vreme.


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Dar viteza diverselor telegrafe cu ac

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nu a depasit niciodata
in jur de 60 de litere pe minut -

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