With this system you can disconnect phone lines in case of need for protection. The circuit is from a 1989 documentation working only with analog lines.
This circuit is from the 1993 Motorola Linear Interface ICs. Equivalent operating may be used and...
Through the TTL output this circuit can be used as a shield. The sensor is a platinum probe, and...
This alarm with sensors in series and parallel was found in the 1995 Encyclopedia of Electronic...