Editing Negative-feedback amplifier (section)

==History==
Paul Voigt patented a negative feedback amplifier in January 1924, though his theory lacked detail.<ref>{{Cite book | url=https://books.google.com/books?id=dunqt1rt4sAC&q=Voigt+Negative+Amplifier&pg=PA767 |title = Op Amp Applications Handbook|isbn = 9780750678445|last1 = Jung|first1 = Walt|year = 2005| publisher=Newnes }}</ref> [[Harold Stephen Black]] independently invented the negative-feedback amplifier while he was a passenger on the Lackawanna Ferry (from Hoboken Terminal to Manhattan) on his way to work at [[Bell Laboratories]] (located in Manhattan instead of New Jersey in 1927) on August 2, 1927<ref name=Black1>{{cite journal
  | last = Black
  | first = H. S.
  | title = Stabilized Feedback Amplifiers
  | journal = Bell System Tech. J.
  | volume = 13
  | issue = 1
  | pages = 1–18
  | publisher = American Telephone & Telegraph
  | date = January 1934
  | url = http://www.alcatel-lucent.com/bstj/vol13-1934/articles/bstj13-1-1.pdf
  | doi = 10.1002/j.1538-7305.1934.tb00652.x
  | access-date = January 2, 2013}}</ref> (US Patent 2,102,671,<ref>{{Cite web |last=Black |first=Harold |date=1937-12-21 |title=U.S. Patent 2,102,671: Wave Translation System |url=http://www.sos.siena.edu/~aweatherwax/electronics/black_patent.pdf |url-status=dead |archive-url=https://web.archive.org/web/20141006074403/http://www.sos.siena.edu/~aweatherwax/electronics/black_patent.pdf |archive-date=2014-10-06 |access-date= |website=www.eepatents.com}}</ref> issued in 1937). Black was working on reducing [[distortion]] in [[repeater]] amplifiers used for telephone transmission. On a blank space in his copy of ''The New York Times'',<ref>Currently on display at Bell Laboratories in Mountainside, New Jersey.</ref> he recorded the diagram found in Figure 1 and the equations derived below.<ref name=Waldhauer>
{{cite book 
|author=Waldhauer, Fred 
|title=Feedback
|page=3
|year= 1982
|publisher=Wiley 
|location=NY
|isbn=0-471-05319-8 
|url=http://worldcat.org/isbn/0471053198}}
</ref>
On August 8, 1928, Black submitted his invention to the U. S. Patent Office, which took more than 9 years to issue the patent. Black later wrote: "One reason for the delay was that the concept was so contrary to established beliefs that the Patent Office initially did not believe it would work."<ref name=Black2>
{{cite news
|author=Black, Harold
|title=Inventing the negative feedback amplifier
|date= December 1977
|publisher=IEEE Spectrum}}
</ref>