The Philbrick Archive and Operational Amplifier

 Educational Tutors, History Vintage  No Responses »
Mar 042011
 

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 Philbrick Archive and Operational Amplifier

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.

Bob Pease’s desk circa 1970 at Teledyne-Philbrick, as photographed by student intern Stu Brennan.

From EE Tech Metrics – dapj

Parallel Controlled Power Supply

 Schematics  No Responses »
May 052010
 
Parallel Controlled Power Supply

Parallel-controlled circuits operate as self-controlled, variable resistors, connected in parallel to the load impedance (parallel loads). They react extremely fast and also control immediately pulses and very short mains break-downs, resulting from strong loads. These devices are preferably used in TV receivers, which have a B-class operated audio output stage. Without any parallel control the [...]

Antenna-amplifier with BFT 12 for FM-range

 Amateur Radio, Schematics  No Responses »
May 042010
 
Antenna-amplifier with BFT 12 for FM-range

The only way to improve the reception of FM-signals or particularly of stereo FM-signals under disadvantageous receiving conditions is to amplify the antenna signal. This should be made directly at the antenna, since the loss is increased meter by meter of any cable. In most cases higher line attenuations can be expected than usually calculated. [...]