The Travel Touch Alarm can be used to provide a audible alarm when someone touches the door knob or handle of your hotel room.
The Sun – Up Alarm can be used to provide a audible alarm for when the sun comes up or it can be used in a dark area and detect when a light comes on. It can also be used to detect a light beam, headlights etc.
This alarm circuit is based on two 555 timers. The alarm will sound your car horn if anyone opens the car door while the circuit is armed.
This is a simple – easy to build – alarm circuit. For power – I used a small 9-volt battery. But the circuit itself will work from 5 to 15-volts – just choose a buzzer that’s suitable for the voltage you’re using. The standby current is virtually zero – so the battery life is good.
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.