Intruder Alarm Circuit

Overview

This circuit is designed to alert the user when an unauthorized person enters the home. It works by detecting changes in light intensity using a photoresistor (LDR).

How It Works

• The LDR is placed opposite to a laser light source.
• When the laser light is uninterrupted, the buzzer and LED remain OFF.
• If the laser light is blocked or moved away, the buzzer and LED turn ON, indicating an intrusion.

Simulation Results

🔹 Laser light is ON and not disrupted – Buzzer and LED are OFF

🔹 Laser light is OFF or moved far away – Buzzer and LED are ON

Breadboard Implementation

📌 Real-world implementation of the circuit on a breadboard:

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