Karl Dale Swartzel Jr. (June 19, 1907 - April 23, 1998) was the inventor of the operational amplifier (or 'opamp'). He filed the patent for the 'summing amplifier' in 1941 when working at Bell Labs.[1]
Notes and References
US . 2401779 . Summing amplifier . 11 June 1941 . 1 May 1941 . 1 May 1941 . Karl D. Swartzel Jr. . Bell Telephone Labor Inc..
