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This is a single zone alarm – with automatic exit, entry and siren cut-off timers. It will accommodate all the usual types of normally-closed input devices – such as magnetic-reed contacts – foil tape – PIRs etc. When the alarm is activated – the siren will sound for a fixed length of time. Then it [...]

This circuit features automatic Exit/Entry delays, timed Bell Cut-off and System Reset. It has provision for normally open and normally closed switches and will accommodate the usual input devices such as Foil Tape, Pressure Mats, Magnetic Reed Contacts, Passive Infrared Detectors and Inertia (Shock) Sensors. The green Led should be lighting before you set the [...]