Very cool resource: GAP/R -- George A. Philbrick Researches
This site is a free non-profit repository of materials from GAP/R George A Philbrick Researches, the company that launched the commercial use of the Operational Amplifier in 1952.The design of the Operational Amplifier was one of those watershed moments in electrical engineering. Here was a circuit that could be made to do a lot of different functions, the selection of which was determined by only a handful of external components. A true "magic box". Growing up, I was aware of Philbrick during his Teledyne Philbrick incarnation and when I became interested in electronic music and sound effects, the op-amp was a key component in virtually any circuit you could build -- oscillator, filter, mixer, envelope generator, sequencer -- you name it and it had op-amps in it. A very cool resource...
I dedicate this site to the many engineers that gave the Analog industry its great start with their state-of-the-art Philbrick products, and by setting new professional standards, and creating new ways to solve engineering problems with the application of analog elements. After Philbrick, these engineers went on to lay the foundations of the analog industry in new companies like Linear Technology, Analog Devices and National Semiconductor, among many others.
The first commercial Operational amplifier was the K2-W op-amp. It was based on the amplifier used in the Philbrick modular Analog-Computor "black boxes". That amplifier's basic circuit architecture, in turn, was probably inspired by an earlier amplifier designed by Loebe Julie (Dan Sheingold and Bob Pease, thanks for helping me with this information). The K2-W Operational Amplifier entered the commercial market in 1952. It performed mathematical Operations in analog computers. Soon after, the K2-W and its successors saw wide application in industry. The Analog Computer was one educational vehicle to familiarize the engineer and the engineering student, with Operational Amplifier techniques. GAP/R also took on a crucial educational leadership role with application guides and tutorials.
