Introduction

Have you heard of burglars breaking into houses in your neighborhood, and you are worried about your home being broken into? Do you want to prevent your pet from sneaking out of your room at night? Or do you have precious things hidden in cabinets or drawers?

Worry no more! You can install an intruder alarm that will go off whenever someone enters or touches your precious items.

This simple intruder alarm circuit works when two conductor plates touch each other, making a close circuit, allowing electricity to flow to the buzzer to emit a loud sound. When the door is closed, the alarm is disengaged. When the door connected to the circuit is opened, the alarm is engaged.

The clothespin switch connected to the door is the key variable in the circuit. It has two metal screws separated by an insulator which is attached to the door. When the door is opened, the insulator will be pulled out and the metals will meet and conduct electricity. It will then trigger the circuit to produce sound.

Different variations can be done for this circuit. You can innovate by making the switch more modern, applying magnetism or sensors. You can also redesign the circuit and place it in an enclosure or customize it to suit your preferences.

Video Tutorials

Wiring Diagram

Troubleshooting Tips: