Nonelectric "telephone"
Overall, the phone - is any device capable of transmitting sound over long distances. Most first telephones were mechanical devices that are based on sound propagation in continuous media (air) or other physical means, as opposed to electric devices using electromagnetic signals.
According to a letter to «Peking Gazette», in 968, a Chinese inventor Kung-Fu-wing created thumtsein, which is likely to transmit sound through the pipes. Talking through pipes used today in the transmission of sound over short distances between fixed points (on ships, companies, etc.).
"Rope phone" is also known for centuries. There are two diaphragms connected with string or wire.
Electric phone
Millennium after millennium people communicate only by using sound propagation in a continuous medium - air. To send messages over long distances use primitive methods, such as whistles, gongs or drums. An invention is a device that transmit and receive audio would use the properties of electricity, preceded the
appearance of the electric telegraph and its successful application in the first half of XIX century.
1849-1854 years. Charles Burselem, a mechanical engineer and deputy inspector Paris telegraph, developed the idea of calling. The first principle of the phone Sh Bursel outlined in his thesis in 1854, but the practical implementation of a telephone connection, it never arrived. Sh Bursel was also the first to use the word "phone". [Citation needed 953 days]
In 1860, the U.S. immigrant Italian descent Antonio Meucci demonstrated a device that could transmit sounds by wire, and he called Telectrophon. Meucci filed a patent for his invention in 1871.
In 1861, German physicist and inventor Johann Philipp Reis demonstrated another device that could also transfer music tones and verbal communication by wire. The machine had a microphone original design, the power supply (galvanic battery) and speaker. Flight called himself designed his device Telephon.
Telephone, patented in the U.S. in 1876 Alexander Graham Bell, was called a "talking telegraph". Bell served as the tube at a time and for transmission and reception of human speech. The phone A. Bell was not the call was later invented counterpart A. Bell - T. Watson (1878). Make calls made through the tube by a whistle. The range of this line does not exceed 500 meters.
Alexander Graham Bell applied for the patent office in Washington for his invention February 14, 1876. Two hours later, a request for "Apparatus for transmitting and receiving vocal sounds wire method" filed by E. Gray of Chicago.
March 7, 1876 Alexander Graham Bell received a patent on the invention of the telephone. Curiously, A. Bell tried not invent the phone, and the "harmonic telegraph". While in telegraphy is facing huge shortage of lines.
June 25, 1876. Alexander Graham Bell first demonstrated his phone at the first World Electrical Exhibition in Philadelphia.
B 1877 Vaden inventor applied for calling a subscriber telegraph key, which closed circuit ring (key was later replaced by the button). That same year, the St. Petersburg plant by German company "Siemens and Halske" started to make phones with two handsets - one for receiving the other for voice.
B 1878 Russian electrical P. M. Golubitsky used in telephone handsets capacitor and developed the first Russian phone original design, which was used several permanent magnets. In 1885, Golubitsky developed a system of centralized power microphones phones.
In the years 1877-1878, Thomas Edison suggested using a carbon microphone instead of a coal shaft coal powder, that is, invented the carbon microphone with a carbon powder, which worked almost unchanged until 1980, and in some places still works.
December 31, 1898 to open the phone line Moscow - Petersburg.
The first commercial telephone conversation between New York and London took place January 7, 1927 on transatlantic telephone cable. USSR was connected to New York City via the cable 14 April 1936. The first call took place between the People's Commissar of Communications and duty Telephone and Telegraph Company of New York. Communication was held on established international phone lines in French.
Prior to the Cuban missile crisis phone for communication between the two countries was unpopular. Connection then realized by political observers Zorin, who contacted Edward Kennedy [citation needed 374 days]. Then a straight line was arranged between the USSR and the USA.
The history of the further development of the phone includes an electric microphone, came to replace coal, speakerphone, tone dialing, digital audio compression. New technology IP-telephony, ISDN, DSL, cellular, DECT.
Radiotelephony
Represent a system consisting of a base, to which the analog or digital subscriber lines from the PBX and one or more wireless handsets that can both transmit to each other, and to call on external lines. Operate on different frequencies. Previously released only analog devices with a carrier frequency of a few tens of MHz. These devices were exposed to noise, and sometimes in his pipe could hear conversations on the same phone from the next apartment. These phones were mainly equipped with only one tube.
Then the phone went on sale with a carrier frequency of 900 MHz and digitally encoded signal. In these devices, the sound quality is better, increased range of reliable operation and prevent accidental tapping of your neighbors talking. The next step was phone with a carrier frequency of 2.4 GHz. These devices are sometimes made with multiple handsets, increased the range and sound quality.
Recently the phone went on sale with a carrier frequency of 5.8 GHz with the communication range is sometimes enough to work within a block with good sound quality. These phones often allow you to connect multiple tubes and generally operate without interference in apartments equipped with other wireless devices (such as wireless internet). These carriers are working for mobile phones sold in the U.S. and Canada.
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