THE TELEPHONE ESENGELDY ALYHAN

STAGES OF DEVELOPMENT OF PHONES. The phone ("far-distance" from Greek τλε - far and φωνή - voice, sound) is a device for transmitting and receiving sound over a distance. Modern phones transmit by means of electrical signals. According to statistics, 72% of young people and 39% of older people can not imagine a day without a mobile and landline phone. In general, a phone is any device capable of transmitting sound over a long distance.

HISTORY

NON-ELECTRIC "PHONES" The earliest telephones were mechanical devices that were based on the propagation of sound in continuous media (air) or other physical means, unlike electrical appliances using electromagnetic signals. According to a letter in the "Peking Gazette", in 968, the Chinese inventor of Kung Fu-wing created a thumtsein, which probably transmitted sound through pipes. Talks through the pipes are still used today in the transmission of sound over short distances between fixed points (on ships, enterprises, etc.). "The rope phone" is also known for many centuries. In it two diaphragms were connected by a string or wire.

ELECTRIC PHONES. The invention of the device, which would use the properties of electricity to transmit and receive sound, was preceded by the appearance of an electric telegraph and its successful application during the first half of the 19th century years. Charles Bursel, a mechanical engineer and vice- inspector of the Paris Telegraph, developed the idea of telephony. The first principle of the phone S. Bursel outlined in his dissertation in 1854, but before the practical implementation of telephone communication, he did not reach. S. Bursel was also the first to use the word "telephone".

In 1860, an immigrant of Italian origin, Antonio Meucci, demonstrated in the US a device that could transmit sounds over wires, and named Telectrophon. Meucci applied for a patent of his invention in 1871.

In 1861, the German physicist and inventor Johann Philippe Reis demonstrated another device that could also transmit musical tones and human speech over wires. The device had a microphone of original design, a power source (galvanic battery) and a speaker. Reyes himself called the device Telephon designed by him.

The phone, patented in the USA in 1876, by Alexander Bell, was called the "speaking telegraph". Bell's tube served in turn for both transmission and reception of human speech. A. Bell's phone did not ring, later it was invented by A. Bell's colleague - T. Watson (1878). The call of the subscriber was made through the tube with a whistle. The range of this line did not exceed 500 meters. June 25, Alexander Bell first demonstrated his phone at the first World Electrical Exhibition in Philadelphia.

In 1877, the inventor Waden used a telegraph key to call the subscriber, which closed the chain of the bell (later the key was replaced by a button). In the same year, the St. Petersburg plant of the German firm Siemens and Halske began manufacturing telephone sets with two telephone handsets - one for receiving the other for voice transmission.

In 1878 the Russian electrical engineer P. M. Golubitsky used a condenser in telephone sets and developed the first Russian phone of the original design, in which several permanent magnets were applied. In 1885 Golubitsky developed a system for centralized supply of microphones for telephone sets.

In , Thomas Edison proposed using carbon powder instead of a coal rod in coal microphones, that is, he invented a coal microphone with coal powder, which practically did not change until 1980, and in some places still works.

The first commercial telephone conversation between New York and London occurred on January 7, 1927 over a transatlantic telephone cable.

MODERNITY

RADIOTELEPHONE A cordless telephone (radiotelephone) is a telephone that communicates with a telephone line using radio communication, which provides freedom of movement to a speaker not connected to this line. Such a telephone consists of a base station and one or more wireless terminals (handsets). The base is connected to a wired telephone network; The connection between the tubes and the base is realized by means of modulated radio waves of this or that frequency. In addition to communication with the telephone network, cordless phones can support additional functions, for example, communication between several handsets of the same base, an answering machine. The range of action is from 50 to 300 meters (an average of about m.

Also, radiotelephones include DECT phones and ISDN. DECT - Represents an easy system consisting of a base to which lines from a public automatic telephone exchange are connected and one or several wireless handsets that can communicate both among themselves and ring over external lines. ISDN is a digital network with service integration. Allows you to combine telephone and data services.

CELL PHONES A radio communication system aimed at providing the user with a connection anywhere. It consists of a large number of base stations, interconnected by central switches, and cellular phones. The cellular phone is switched on at the nearest base station when switched on and, if its number is called, the central switch finds the phone and transfers the call to it via the nearest base station. During the movement, the cellular phone is transferred from one base station to another without disconnection, even if there is a conversation (the Handover function). The base stations are called cell towers, there are micro towers with a broadcasting radius of meters, averages meters and a macro of meters.

SATELLITE PHONE This is a mobile phone that transmits information directly through a special communication satellite. Depending on the communication operator, the coverage area can be either the entire Earth, or only certain regions. In size, the satellite phone is comparable to a conventional mobile phone released in the 1980s and 1990s, but usually has an additional antenna. There are also satellite phones in a stationary version. Such phones are used for communication in areas where there is no cellular communication.

IP TELEPHONY This is a communication system that provides the transmission of a voice signal over the Internet or any other IP-networks. Properties: conference Call forwarding Automatic redial Caller identification Since 2005, the use of specialized programs (for example Skype) has made IP-telephony practically free.

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