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.
Written in an article in Radio Electronics magazine in April 1987, this circuit triggers an alarm...
This circuit was found in the April 1993 Electronics Now magazine. With it, it is possible to...
This circuit was obtained in a1969 magazine. The magazine no longer exists, but the circuit can be...