Other insulating techniques, such as covering the insulated wires with tin foil and using additional insulating layers, were employed. The technique of wrapping the conducting wires in lead was developed to eliminate electromagnetic noise in the lines. In the 1880's the major telephone cable concerns were noise elimination, waterproofing and fitting more wires in each cable. Telephone cables were needed to replace the large number of aerial wires present in the cities. There was a large demand for telephone cables. They were insulated with cotton, cotton impregnated with paraffin, gutta percha or a rubber compound, and then in wrapped in lead. The cables contained up to 100 copper wires. The cables made by the different manufacturers were very similar but not identical. Some of the early telephone cable applications were across the East River Bridge, under the North River between New York and New Jersey and across the Delaware River from Philadelphia to Camden. By 1887 all of the newly manufactured cables were metallic circuit cables. Early cables were single grounded wires followed by metallic circuits lines after their development. Telephone cables were employed for aerial, underwater and underground use around 1879. Gutta percha and various rubber compounds were used for insulating and water proofing the telegraph and early telephone cables. Early telephone cables relied upon the technology used in the manufacture of telegraph cables. Better insulation, both electromagnestic and water resistance, were required. Many telephone wires were contained in one telephone cable. Interest grew in the development of telephone cables. Advances were also made in design of insulators and wire transpositions. There was a gradual conversion from grounded to metallic circuit lines between 18. The entire overhead wiring system had to be replaced with two wires instead of one for the metallic circuit lines. The installation of metallic circuits was both physically and financially difficult. The metallic circuit was an important development in telephony because it eliminated a lot of the electrical disturbances and unwanted noise in the lines. The metallic circuit or two-wire circuit was developed and patented by Alexander Graham Bell in 1881. The use of hard drawn copper wire then expanded into electrical transmission lines and throughout the electrical industry. Many manufacturers started producing hard drawn copper wire in order to meet the increased demand for telephone wires.
In 1885 a hard drawn copper telephone line was set up between New York and Philadelphia. In 1884 an experimental long distance telephone line made of copper was set up between Boston and New York. The hard drawn copper wire was strong enough for overhead wires and copper took over the telephone wire market.
#WHEN WAS THE TELEPHONE INVENTED SERIES#
He had soft, annealed copper wire drawn through a series of dies in order to increase its tensile strength. Then in 1877 Thomas Doolittle developed the process for hard drawn copper wire in the Naugatuck Valley of Connecticut. Some wires were galvanized for corrosion resistance, but corrosion problems were never the less prevalent. The telephone lines were single grounded wires made of iron or steel. The first telephone lines were overhead lines, placed on telephone poles or attached to racks on rooftops. 1 Telephone lines were needed to connect private telephones with the central interconnection facility. A central interconnection facility was needed, a place where telephone lines would be connected as desired.
People wanted to be able to talk with more than one other household. The use of private lines was, of course, very restrictive. It connected the home of Charles Williams Jr. The first telephone line was set up in Boston in 1877. In other words, each person that had a telephone could talk to one other telephone. At first, the telephone lines were separate lines that connected pairs of telephones. Alexander Graham Bell invented the telephone over 100 years ago.
0 kommentar(er)
