This filter is from a 1977 publication. The circuit employs three 741 or other operational amplifiers. The supply must be symmetrical and the components with (*) are low tolerance.
This signal generator found in Japanese documentation of 1973 uses an unusual integrated circuit...
This circuit was obtained in the publication 101 Electronics Projects of 1979. The circuit can be...
We found this circuit in an old European publication. Integrated circuits are not common today and the...