Looking for ideas for a wired gate alarm

[down2earth]

Hi, I'm after some ideas to make a wired gate alarm, I have tried a wireless version and it's hopeless, despite claiming a 100M range I have found it has to be so close to the house that the 'visitor' is by the door by the time the alarm goes off.

My plan was to use bell wire connected to two magnetic contacts, which is in turn connected to a standard doorbell (overall distance about 25 metres), however the problem with this is that the bell will be going off all the time the contacts are parted, if anyone has any ideas I would be very grateful.

Regards

D2E

 

[telectrix]

Timer relays / Multifunctional relays

try here.