Introduction: Tutorial: How to Make Laser Alarm System

Hey guys, today we are going to make laser alarm system. Have you seen any movie that if any object blocking some sort of laser, it will trigger an alarm. We are going to make something similar like that but with lower cost. You can use this project to apply it at home or anywhere you want as long as it is suitable.

First thing first that you need are the 'ingredients':

1. MB-04 hobby kit

2. MB-12 hobby kit

3. DC Jack (female)

4. AC/DC Adapter 9V

5 . Piezo Buzzer (alarm sound)


7. Multicore wire

8. laser diode 65nm

9. Recycled box

10. Straw

Tools that you need are:

1. Scissors

2. Screwdriver

3. Ruler

We provide links for you to buy all the components.

Step 1: Let's Do This!

This alarm system consists of two parts:

1. Alarm with timer

2. Laser

Alarm with timer

How long the alarm will switch on can be set by tuning the potentiometer. The higher the resistance, the longer the alarm will sound.


Laser will point to LDR. If laser is being blocked by any object, the alarm will sound.

You can also use battery to replace by power supply. But, the battery will drain very fast because laser diode and buzzer consume a lot of energy. That is why we use power supply in this system. Feel free to design your Laser alarm system as creative as you want such as change recycled box with something more strong and sturdy. But, remember to keep it cost friendly.

Please refer to the circuit diagram to make sure the project will work as it should.

We already make a tutorial video at Youtube. It is more easier to understand if we see than read.

Good luck on your project. Leave your comment below.