This notch filter was found in National Semiconductor documentation from the 1980s. Operational amplifiers are from that era. The configuration can be adapted to use modern operational amplifiers.
This sinusoidal oscillator was found in Radio Electronics in 1989. It uses a 741, but other...
This is the circuit of a commercial flash from the 60’s. The circuit was published by the march...
This circuit is suggested by Motorola in its 1990 Linear Databook. The integrated circuit is no...