We found this circuit in the National Semiconductor's Linear Applications Handbook of 1994. The circuit uses an operational transconductance amplifier.
This tone generator for CW was found in a publication by Gernsback from 1960. The circuit makes use...
This circuit was obtained in an old US 1974 documentation when Nixie tube displays were common. The...
This circuit was found in an 80s National Semiconductor documentation. The configuration holds...