Expandable Wire Break Alarm Circuit

I need a simple wire-loop 'break' alarm that energizes a relay which can be expanded i.e. all the different wire loop turns on the single common relay.

It should have a manual reset switch i.e. in case of a break in wire loop, relay should be energized until reset switch is pressed even if wire loop is reconnected again.

Please help me

Joseph J K
India

Sorry i forget to mention operating voltage; it is 12V

Lots of em out there. Here's one random one.
**broken link removed**

Any real alarm would use a micro processor and have a logic system to cope with the variables required to suit the applications.

consider using a pic (or a picaxe but i will be hated for using that word)

Pete.

If you take the super-simple route, it can be done with one relay. Take a look as to how start-stop stations are wired. You will also need an alarm silence. Loosing power sets off the alarm as well unless it's backed up. It would also be power hungry and difficult to detemine which loop is broken. There are lots of reasons why not to do it this way, but there may be a reason to make it super simple too.

A relay is wired such that one of it's NO contacts complete the circuit to the relay. A NO push button is wired across the relay NO contacts. The NC loop is wired in series with the relay coil. A NC contact is used for the alarm.

Add an alarm and an alarm silence switch.

Remember that no power means alarm.