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.
We found this circuit in an old documentation. Its purpose is to turn on warning lights when the...
This percussion circuit was found in an Electronics World of 1968. The transistor may be general...
We found this transmitter circuit with a single chip in the Motorola Linear Databook of 1990. The...