We found this circuit in a 1966’s General Electric documentation. The circuit uses diodes in unique GE packages, available at the time.
This UAA170 application circuit was taken from Siemens' own integrated circuits manual from 1976....
We found this circuit in the 1960 Mullard transistor reference manual. The phototransistor can be a...
Found in National Semionductor documentation this circuit combines a tone control with an...