This circuit allows the activation of a remote telephone bell made with a common piezoelectric capsule. The circuit does not need power, as it is powered by the line call signal itself.
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...