This circuit generates sinusoidal signals that depend on the input oscillator. The circuit is from a Radio Elecrtronics from April 1988. The signals are in the range of a few hundred kilohertz.
This didactic circuit was found in a 2001 documentation. It presents the result of programming in binary...
This VFO circuit generates signals from 2 Hz to 50 Hz. We found it in Popular Electronics from...
This circuit can be used as a buzzer from 3 different locations, allowing you to identify where it went...