Automatic Intruder Alarm


Posted on Aug 30, 2012

This is a simple single-zone burglar alarm circuit. Its features include automatic Exit and Entry delays and a timed Bell/Siren Cut-Off. It`s designed to be used with the usual types of normally-closed input devices such as - magnetic reed contacts - micro switches - foil tape - and PIRs. But it can be Easily Modified to accept normally-open triggering devices - such as pressure mats.


Automatic Intruder Alarm
Click here to download the full size of the above Circuit.

It`s easy to use. First check that the building is secure and that the green LED is lit. Then move SW1 to the "set" position. The red LED will light. You now have about 30 seconds to leave the building. When you return and open the door - t




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

High speed warning device
BTL Mono Amplifier With DC Volume Control Circuit
Solar Charger Schematic
grid frequency
monostable multivibrator 555 timer
Common-base Colpitts oscillator circuit
Mains under voltage voltage protection circuit
Based LT3756 buck - boost mode drive circuit diagram



Top