With this circuit found in an American documentation from 1969 it is possible to vary the selectivity (Q factor) of a tuned circuit. The operational is from that time.
Found in an Electronic Design from the 90s, this circuit generates a mathematical function given by the...
This circuit was obtained in the Audio Handbook of the National Semiconductor of 1977. The...
This circuit was obtained in the publication 101 Electronics Projects of 1979. The circuit can be...