Introduction

In this tutorial, we will show you how to make a mini laser security alarm system using BC547.

There is a circuit that will help you to make the model easily.

Supplies

We need some tools and materials to make this mini laser security alarm system with transistor using simple circuit:

Tools

• Hot glue gun
• Soldering iron

Materials

• BC547 transistor
• Buzzer
• 10k resistor
• LDR
• 3v coin cell and holder
• Wire
• Laser diode
• Holder

Steps To Make Mini Laser Security Alarm System Using BC547

Just follow these steps to make this DIY security alarm system:

Step 1: Attach the transistor to the buzzer.

Step 2: Now, connect the legs of the transistor with the buzzer ( as shown in the picture).

Step 3: Now, connect LDR in the middle leg and 3^rd  leg, and transistor with middle leg and buzzer using a soldering iron.

Step 4: Attach the whole circuit to the holder.

Step 5: Connect the wire with it and the coin cell.

Step 6: Now, take another holder and connect the laser diode with the coin cell.

Step 7: When you turn on the laser diode, and the buzzer will come in contact with the laser, it’ll start a sound.

Recommendation

This tutorial will help students understand the working and principle concept of a security alarm and how we can make it at home for your science project.

Things To Remember

• Use the leftover material from previous crafts.
• Be careful while using soldering iron.
• Take the help of an adult while making models.

Cisco Ramon

Cisco Ramon is an American software engineer who has experience in several popular and commercially successful programming languages and development tools. He has been writing content since last 5 years. He is a Senior Manager at Rude Labs Pvt. Ltd.