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The waveform of 230 V and 50 Hz compared with 120 V and 60 Hz. The utility frequency, (power) line frequency (American English) or mains frequency (British English) is the nominal frequency of the oscillations of alternating current (AC) in a wide area synchronous grid transmitted from a power station to the end-user.
Prior to the emergence of television as the dominant entertainment medium in the 1950s, families gathered to listen to the home radio in the evening. The Golden Age of Radio , also known as the old-time radio ( OTR ) era, was an era of radio in the United States where it was the dominant electronic home entertainment medium .
15 March – The Copenhagen Frequency Plan is implemented by broadcasters throughout Europe. 1 May – Springbok Radio, South Africa's first commercial radio station, takes to the airwaves. It will broadcast for 35 years, until 31 December 1985.
Italian physicist and electrical engineer Galileo Ferraris publishes a paper on the induction motor, and Serbian-American engineer Nikola Tesla gets a US patent on the same device [4] [5] 1890: Thomas Alva Edison invents the fuse: 1893: During the Fourth International Conference of Electricians in Chicago, electrical units were defined 1893
The 32-volt system could also power other specially made appliances as well as electric lights around the farm. Other farm radios, especially from the late 1930s to the 1950s, reverted to using a large "A-B" dry cell that provided both 90 V for the tube plates and 1.5 V for the tube filaments, as did most tube-based portable radios of that era.
Voltages used for electric power transmission increased throughout the 20th century. [50] The first "high voltage" AC power station, rated 4-MW 10-kV 85-Hz, was put into service in 1889 by Sebastian Ziani de Ferranti at Deptford, London. [33] The first electric power transmission line in North America operated at 4000 V.
1892: Scottish electrical engineer and astronomer George Forbes suggests Branly's filing tube may react in the presence of Hertzian waves. 1893: Nikola Tesla delivers a lecture "On Light and other High Frequency Phenomena" before the Franklin Institute in Philadelphia and the National Electric Light Association St Louis.
The Western Electric model 500 telephone series was the standard domestic desk telephone set issued by the Bell System in North America from 1950 through the 1984 Bell System divestiture. The successor to the model 302 telephone , the model 500's modular construction compared to previous types simplified manufacture and repair and facilitated a ...