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| | A telephone is a device for transmitting sound at large distances with the help of electric signals.
History:
Non-electric “telephones”:
Overall the telephone is any mechanism which can transmit sound at large distances. Unlike electric devices based on electro-magnetic signals, the first telephones were mechanical devices based on the transmission of sound by using air or other physical means.
According to a letter to Peking Gazette, in 968, a Chinese inventor Kung–fu-wing created a thumtsein which probably transmitted speech through pipes.
Pipes for holding conversations are used even today.
Known for centuries was also a rope telephone: when two diaphragms were tied with a cord or wire, transmitting sound from one end to the other by vibrations of the cord but not through a current.
This term has other meanings too.
What we call now a telephone, is a fruition of the work done by many people. Documentary evidence says that one of the first successful electrical devices which through wires transmitted music tunes and distinct speech was created by Johann Philipp Reis in Germany in 1861.
The instrument had a transmitter of a quaint design, the power source was an electrochemical battery and it had a dynamic speaker. Reis himself called the device designed by him a telephone. In the same year Antonio Meucci, an Italian immigrant in the USA, demonstrated another device which also could transmit sound through wires and was named by him a teletophone. The telephone, patented in 1876 by the American Alexander Bell was called the “speaking telegraph”. Bell’s handset was used both for the transmission and receiving of audio. Bell’s telephone did not have a bell. Calling was alerted at the other end, or the exchange operator, by whistling into the transmitter. The distance between these lines did not exceed more than 500meters.
In 1877, inventor Vaden applied the telephone key which closed the bell circuit (later the key was replaced by a switch). In the same year a Petersburg branch of the German company “Siemens and Galske” started manufacturing telephone instruments with two handsets – one for receiving and the other for the transmission of speech.
In the next year, the Russian electro-technician P.M. Golubitsky applied a condenser in telephone instruments and developed the first Russian telephone with an interesting design. This comprised of several permanent magnets. In 1885, Golubitsky developed transmitters with a centralized system of power supply in the telephone instruments.
Thomas Edison invented a carbon granule transmitter which worked up to 1980 without any changes.
The first commercial telephone conversation between New York and London took place on the 7th of January 1927 through a Trans- Atlantic telephone cable.
The history of further developments in the telephone include: an electric transmitter in place of a carbon one, a loud connection, tone dialing and digital volume compression. New technologies: IP-telephony, ISDN, DSL, cellular transmission and DECT.
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