We found this circuit in a 1977 factory documentation. The operational amplifiers can be 741 and the symmetrical power supply. Capacitors can be changed for operation at other frequencies.
We found this circuit in a Radio Electronics from October 1976. The components are still common, but...
LEDs with appropriate resistors can be used in place of the lamps in this circuit obtained in a...
Datasheet of We found this circuit in the 1982 SGS Linear Integrated Circuits manual. A | table...