Learn how the magnet activates the Intruder Alarm! A fun construction to discover how a magnetic switch works in an electrical circuit! 

OPERATION: Activate the alarm and close the door. If someone opens the door even a small crack, the alarm will sound. Close the door again or deactivate the alarm to stop the buzzer. When the door is closed and the triangles on the magnet and the base align, the disk is attracted by the magnet to one side of the hole area. When the door opens, the magnet moves away from the base and the attraction from the magnet is no longer strong enough to hold the disk. The disk slides down to the bottom of the hole area and remains between the two plates with the holes. This acts as a switch, completing the circuit and allowing the current to flow through the buzzer.

CONTENTS: Part A: Base x 1, Part B: Cover x 1, Part C: Magnet x 1, Part D: Magnet Holder x 1, Part E: Hole Plate Set x 1, Part F: Battery Cover x 1, Part G: Adhesive Tape, Part H: Metal Disk x 1, Part I: Terminal Covers x 3, Part J: Screws x 3, Part K: Wheel Screws x 2. Also required but not included in this package: 2 AAA 1.5V batteries, a small screwdriver. Instructions in Greek are included.