Telepon

thumb|right|222px|Telefon Touch Tone® kalawan lampu panunggu pesen

[thumb|222px|1896 Telefon ([Swedia)]]

**Telepon** nyaéta alat telekomunikasi anu digunakeun pikeun ngirimkeun jeung narima sora; paling ilahar sora manusa. Telepon kiwari mangrupa kalengkepan rumah tangga nu paling ilahar di dunya. Lolobana, sinyal sora tina telepon diliwatkeun kana jaringan telepon umum.

## Prinsip dasar 
Telepon ngirimkeun dua rupa informasi: sinyal jeung sora siliganti dina waktu nu béda dina sapasang kawat. Terminal telepon ogé dilengkepan ku papan nomer pikeun ngasupkeun nomer telepon (lambang alamat tujuan) waktu rék nelepon ka pamaké telepon lianna.

Waktu panelepon ngangkat gagang telepon, hal ieu mgusikkeun *switch* dina jero terminal anu ngakibatkeun telepon asup kana kaayaan aktif atawa *off hook* di mana hiji résistor *nyambungsingket* kadua kawat anu sapasang kasebut, anu ngabalukarkeun arus listrik DC ngamalir nuju ka sentral telepon. Saenggeus séntral narima arus DC, saterusna séntral ngirimkeun sinyal *nada call setup* sangkan panelepon muter nomer tujuan.

Terminal telepon ogé dilengkepan ku alat isarat (*signaling*) nu ngandung hiji kohkol (bél) pikeun ngingetkeun pamaké ngeunaan kadatangan ajakan nelepon ti pamaké lianna.

Waktu panelepon neken tombol-tombol nomer, hal ieu ngabalukarkeun panghasil (generator) nada dina jero papan nomer ngahasilekun nada DTMF anu ngalambangkeun alamat pamaké telepon lianna. Séntral nyambungkeun sapasang kawat milik panelepon kana sapasang kawat milik pamaké telepon anu dituju sarta méré béja pamaké kasebut ku cara ngirimkeun sinyal nada kirining (dering) anu ngakibatkeun bél dina terminal tujuan disada.

Mangsa telepon henteu aktif (on hook), bel, panghasil sora, alat isarat panghasil sinar atawa alat isarat lianna, disambungkeun kana kawat ku jalan hiji kapasitor. Telepon anu henteu aktif henteu *nyambungsingket* kawat, antukna séntral telepon nyaho yén telepon kasebut dina kaayaan *on hook*; ngan bél anu disambungkeun sacara listrik. Mangsa urang nelepon hiji nomer, séntral telepon ngabangkitkeun sinyal pulsa *tegangan tinggi*, anu ngabalukarkeun alat isarat disada atawa méré nyaho pihak anu ditelepon. Mangsa pihak anu ditelepon ngangkat gagang telepon, *switchhook* megantkeun sambungan kana alat isarat, terus nyambung kana alat pangirim / panarima sora, sarta hiji résistor ngahubungsinket kawat, negeskeun yén telepon geus dijawab jeung dina kaayaan aktif. Lamun kadua pasang kawat *off hook*, pangiriman jeung panarimaan isarat eureun. Kadua beulah pihak nyambung sarta bisa ngobrol ngagunakeun alat pangirim / panarima sora anu aya dina telepon.

Alat pangirim / panarima sora telepon ayana dina gagang telepon nu aya dina terminal, sarta ngandung hiji transmitter (anu mindeng disebut mikropon) jeung hiji panarima atawa *receiver*. Transmitter, anu dibéré énergi tina kawat, ngahasilkeun arus listrik anu robah-robah gumantung gelombang tekenan akustik anu dihasilkeun ku sora. Parobahan arus listrik anu dihasilkeun dirambatkeun sapanjang kawat telepon ka terminal tujuan, di mana arus listrik dimaksud dieupankeun kana gulungan kawat dina *receiver*, anu mangrupa *loudspeaker* miniatur. Arus listrik anu robah-robah dina gulungan kawat ngabalukarkeun inyana maju-mundur, ngahasilkeun gelombang tekenan akustik tina transmitter.

When a party "hangs up" (puts the handset on the cradle), DC current céases to flow in that line, thus signaling to the exchange switch to disconnect the telephone call.

## History 
Credit for inventing the electric telephone remains in dispute. Antonio Meucci, Johann Philipp Reis, Alexander Graham Bell, and Elisha Gray, among others, have all been credited with the invention.

The éarly history of the telephone is a confusing morass of claim and counterclaim, which was not clarified by the huge mass of lawsuits which hoped to resolve the patent claims of individuals. The Bell and Edison patents, however, were forensically victorious and commercially decisive.

### Early development 
The following is a brief summary of the development of the telephone:

* 28 December 1871—Antonio Meucci files a patent caveat (n.3335) in the U.S. Patent Office titled "Sound Telegraph", describing communication of voice between two péople by wire.
* 1874—Meucci, after having renewed the cavéat for two yéars, fails to find the money to renew it. The cavéat lapses.
* 6 April 1875—Bell's U.S. Patent 161,739 "Transmitters and Receivers for Electric Telegraphs" is granted. This uses multiple vibrating steel reeds in make-bréak circuits.
* 11 February 1876—Gray invents a liquid transmitter for use with a telephone but does not build one.
* 14 February 1876—Elisha Gray files a patent caveat for transmitting the human voice through a telegraphic circuit.
* 14 February 1876—Alexander Bell applies for the patent "Improvements in Telegraphy", for electromagnetic telephones using undulating currents.
* 19 February 1876—Gray is notified by the U.S. Patent Office of an interference between his cavéat and Bell's patent application. Gray decides to abandon his cavéat.
* 7 March 1876—Bell's U.S. patent 174,465 "Improvement in Telegraphy" is granted, covering "the method of, and apparatus for, transmitting vocal or other sounds telegraphically … by causing electrical undulations, similar in form to the vibrations of the air accompanying the said vocal or other sound."
* 10 March 1876—The first successful telephone transmission of cléar speech when Bell spoke into his device, “Mr. Watson, come here, I want to see you.” and Watson héard éach word distinctly.

## See also 

* Elisha Gray and Alexander Bell telephone controversy
* Answering machine
* Bell labs
* Bell System
* Carterfone
* Dial tone
* Emergency phone
* Telephone newspaper
* Area code
* Telecommunications
* Telephone switchboard
* Telephony
* Fax
* Mobile phone
* History of mobile phones
* Federal telephone excise tax

## References 
* Coe, Lewis (1995), *The Telephone and Its Several Inventors: A History*, McFarland, North Carolina, 1995. ISBN 0-7864-0138-9
* Evenson, A. Edward (2000), *The Telephone Patent Conspiracy of 1876: The Elisha Gray - Alexander Bell Controversy*, McFarland, North Carolina, 2000. ISBN 0-7864-0883-9
* Baker, Burton H. (2000), *The Gray Matter: The Forgotten Story of the Telephone*, Telepress, St. Joseph, MI, 2000. ISBN 0-615-11329-X
* Huurdeman, Anton A. (2003), *The Worldwide History of Telecommunications*, IEEE Press and J. Wiley & Sons, 2003. ISBN 0-471-20505-2
* Josephson, Matthew (1992), *Edison: A Biography*, Wiley, 1992. ISBN 0-471-54806-5
* Bruce, Robert V. (1990), *Alexander Graham Bell and the Conquest of Solitude*, Cornell University Press, Ithaca, 1990.

## Further reading 
* Robert Sobel, *The Entrepreneurs: Explorations Within the American Business Tradition* (Weybright & Talley 1974), ISBN 0-679-40064-8.
* Kenneth P. Todd, *A Capsule History of the Bell System* 

## Tumbu luar 
* 1911 Britannica "Telephone" article
* 
* Vintage Telephones 
* Mobile Phones - Specifications in a number of languages