landline alarm

[Babybearjs]

does anyone remember the schematic for a landline alarm? I'm thinking of wanting to add some sort of alarm that will sound if the line is cut or damaged indicating a problem... does anyone still remember how that works?

[Key2871]

Yea that's something I know nothing of. Other than its sensing the line voltage and if that goes away it triggers a relay solid state if possible to set off your alarm. Have you googled this or looked at YouTube.
There may just be something on it there.

Edit, here might be something..

https://patents.google.com/patent

[Babybearjs]

what alarms did the phone companies have when a line was cut or damaged? thats kind of what I want to do...