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1920: The first regularly operating radio station KDKA goes on air on 2 November 1920 in Philadelphia, USA. It is the first time electronics are used to transmit information and entertainment to the public at large. The same year in Germany an instrumental concert was broadcast on the radio from a long-wave transmitter in Wusterhausen.
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.
During the first 50 years of commercial use of electric power, standards developed rapidly based on growing experience. Technical, safety, and economic factors influenced the development of all wiring devices and numerous varieties were invented. After the two-prong electric plug was introduced in the 1920s, the three-pin outlet was developed.
1954: Invention of the solar battery by Bell Telephone scientists, Calvin Souther Fuller, Daryl Chapin and Gerald Pearson capturing the Sun's power. First practical means of collecting energy from the Sun and turning it into a current of electricity. 1955: The hovercraft is patented by Christopher Cockerell.
While some early radios used some type of amplification through electric current or battery, through the mid-1920s the most common type of receiver was the crystal set. In the 1920s, amplifying vacuum tubes revolutionized both radio receivers and transmitters.
The electric guitar was a key instrument in the development of musical styles that emerged since the late 1940s, such as Chicago blues, early rock and roll, rockabilly, and 1960s blues rock. Electric guitars are used in almost every popular music genre. [239] U.S. patent #2,089,171 was filed by Beauchamp on June 2, 1934, and issued on August 10 ...
Although the obvious candidate was the Radio Corporation of America (RCA), on October 5, 1920, the Westinghouse Electric & Manufacturing Company took out an option for $335,000 for the commercial rights for both the regenerative and superheterodyne patents, with an additional $200,000 to be paid if Armstrong prevailed in the regenerative patent ...
It was the first convenient battery for the masses and made portable electrical devices practical, and led directly to the invention of the flashlight. The zinc–carbon battery (as it came to be known) is still manufactured today. In parallel, in 1887 Wilhelm Hellesen developed his own dry cell design. It has been claimed that Hellesen's ...