Biography:Karl D. Swartzel Jr.

From HandWiki

Karl Dale Swartzel Jr. (June 19, 1907 – April 23, 1998)[1] was the inventor of the operational amplifier (or 'op-amps'). He filed the patent for the 'summing amplifier' in 1941 when working at Bell Labs.[2]

References

  1. Karl D. Swartzel Jr. at Find a Grave
  2. "Summing amplifier" US patent 2401779, published 11 June 1941, assigned to Bell Telephone Labor Inc.