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.
In the figure we have the way to simulate the function S = AB + CD + E (CB + AD) using 5 switches or...
This circuit was obtained in a 1991 Electronics Handbook. The publication no longer exists, but...
We found this configuration in a documentation for radio amateurs from 1974. The circuit can be...