Circuit Wiring Solution

This brilliant circuit shows a two-zone alarm - with automatic exit, entry and siren cut-off timers.It can be triggered by the usual types of normally-closed input devices - such as magnetic reed contacts - foil tape - PIRs etc.

The circuit will work at anything from 9 to 15-volts. All you need do is select a siren, buzzer and relay to suit the voltage you want to use.