telephone current
41Guardian telephone exchange — Entrance to the Guardian Exchange, Manchester. The entrance is on George Street, between Princess Street and Dickinson Street in Manchester City Centre Guardian Exchange was an underground telephone exchange built in Manchester in the 1950s. It… …
42Reis telephone — The Reis telephone, was an invention by Philipp Reis inspired by a French article in 1854 (by Bourseul) on how to create microphone like devices. His first successful work was achieved in October 1861. In 1862, Reis demonstrated his telephone to… …
43History of the telephone — The history of the telephone chronicles the development of electrical technology that enabled bidirectional human speech conversations over distances farther than a person could shout.Telephone prehistoryMechanical devicesBefore the invention of… …
44Business telephone system — Early model 464G Western Electric key telephone set A business telephone system is any of a range of a multiline telephone systems typically used in business environments, encompassing systems ranging from small key systems to large scale private …
45Romania telephone area codes — Country Code: 40Access code: 0 .As of 2002 the area codes are county codes. They are formed by two digits ( 30 69 ) for the 41 counties, and 1 for Bucharest. Depending on the company that operates the ground line, before the county code another… …
46Direct current — (red curve). The horizontal axis measures time; the vertical, current or voltage. Direct current (DC) is the unidirectional flow of electric charge. Direct current is produced by such sources as batteries, thermocouples, solar cells, and… …
47Tucker telephone — The Tucker Telephone is a torture device designed using parts from an old fashioned crank telephone. The electric generator of the telephone is wired in sequence to two dry cell batteries so that the instrument can be used to administer electric… …
48New York Telephone — Verizon New York, Inc. Type Holding of Verizon Communications Industry Telecommunications Founded 1896 …
49American Telephone & Telegraph — For other companies with similar names, see AT T (disambiguation). Infobox Company company name = AT T Corporation company logo = type = Private (Subsidiary of AT T Inc.) foundation = 1885 location = Bedminster, New Jersey, United States industry …
50Bell Telephone Company — The Bell Telephone Company, a common law joint stock company, was organized in Boston, Massachusetts on July 9, 1877 by Alexander Graham Bell s father in law Gardiner Greene Hubbard, who also helped organize a sister company the New England… …
