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Teletype teleprinters in use in England during World War II Example of teleprinter art: a portrait of Dag Hammarskjöld, 1962. A teleprinter (teletypewriter, teletype or TTY) is an electromechanical device that can be used to send and receive typed messages through various communications channels, in both point-to-point and point-to-multipoint configurations.
The Number Five Crossbar Switching System ( 5XB switch) is a telephone switch for telephone exchanges designed by Bell Labs and manufactured by Western Electric starting in 1947. It was used in the Bell System principally as a Class 5 telephone switch in the public switched telephone network (PSTN) until the early 1990s, when it was replaced ...
Alexander Graham Bell was awarded the first U.S. patent for the invention of the telephone in 1876. Elisha Gray, 1876, designed a telephone using a water microphone in Highland Park, Illinois. Tivadar Puskás proposed the telephone switchboard exchange in 1876. Thomas Edison invented the carbon microphone which produced a strong telephone ...
Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message. Thus flag semaphore is a method of telegraphy, whereas pigeon post is not. Ancient signalling systems, although sometimes quite extensive and sophisticated as in ...
Bank of two-motion switches. The Strowger switch is the first commercially successful electromechanical stepping switch telephone exchange system. It was developed by the Strowger Automatic Telephone Exchange Company founded in 1891 by Almon Brown Strowger. Because of its operational characteristics, it is also known as a step-by-step ( SXS ...
Field telephones are telephones used for military communications. They can draw power from their own battery, from a telephone exchange (via a central battery known as CB), or from an external power source. Some need no battery, being sound-powered telephones . Telephone linesmen ford Lunga River during the Guadalcanal Campaign of World War II.
AT&T push button telephone made by Western Electric, model 2500 DMG black, 1980. A telephone, colloquially referred to as a phone, is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most efficiently the human ...
A telephone number serves as an address for switching telephone calls using a system of destination code routing. [1] Telephone numbers are entered or dialed by a calling party on the originating telephone set, which transmits the sequence of digits in the process of signaling to a telephone exchange. The exchange completes the call either to ...