This 800 Hz sinusoidal oscillator was found in a 1970s American documentation. The transistor supports a modern general-purpose equivalent. The frequency is given by the RC network that can be changed.
The circuit shown is from an old European publication. In it we have the way to activate a relay...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
This circuit was found in an American documentation and can be added to common amplifiers of any...