Don't have any of those luxurious security systems? Lack of budget? You can have your own now without spending too much! Just look around your place and gather these materials!

Step 1: Materials Needed:

For the battery, we used battery out of coins and foil ( the one I posted a while ago) and for the reed switch we used Mahmoud Alaa's homemade reed switch. Thank you Mahmoud Alaa. :)

Step 2: Schematic Diagram

Step 3: Connect and Put It in the Box.

Solder the parts according to the schematic diagram then put it in the box. Make sure that the parts are properly secured. By the way, we just used a junction box instead of a project box because we don't have one.. You can use any box as long as the parts fit in.

Step 4: Test It.

As you noticed, the buzzer rings continuously. But if you put a magnet, the ringing sound will stop. To use this, attach a small rope to the magnet and the other side to the door. If anyone opens the door, the alarm will ring. :)