Alexander M. Nicholson was an American scientist, most notable for inventing the first

crystal oscillator A crystal oscillator is an electronic oscillator circuit that uses a piezoelectric crystal as a frequency-selective element. The oscillator frequency is often used to keep track of time, as in quartz wristwatches, to provide a stable clock ...

, using a piece of

Rochelle salt Potassium sodium tartrate tetrahydrate, also known as Rochelle salt, is a double salt of tartaric acid first prepared (in about 1675) by an apothecary, Pierre Seignette, of La Rochelle, France. Potassium sodium tartrate and monopotassium phospha ...

in 1917 while working at

Bell Telephone Laboratories Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984), then AT&T Bell Laboratories (1984–1996) and Bell Labs Innovations (1996–2007), is an American industrial research and scientific development company owned by mult ...

. He then filed a patent the next year.Nicholson, Alexander M. ''Generating and transmitting electric currents'' , filed April 10, 1918, granted August 27, 1940 His priority was later disputed by

Walter Guyton Cady Walter Guyton Cady (December 10, 1874 – December 9, 1974) was a noted American physicist and electrical engineer. He was a pioneer in piezoelectricity, and in 1921 developed the first quartz crystal oscillator. Cady was born in Providence, Rho ...

who invented the first quartz crystal oscillator in 1921.

References

American inventors Year of birth missing Year of death missing {{US-inventor-stub