#MrNams #MrNamsOfficial ▶️ Subscribe: https://goo.gl/mqbdai 🕸Website: https://mrnams.com ----- FOLLOW US ON: 📸 Instagram: https://www.instagram.com/mrnamsofficial 🐦 Twitter: https://twitter.com/MrNams 🤳Facebook: https://www.facebook.com/MrNamsOfficial ----- Laser Based Security System Science Project This is a simple school science project to make a laser based security alarm system. The system gives an alarm sound when someone crosses the laser beam. Aim To make a laser security system using laser diode and LDR sensor. Components Required Laser diode 3V 3V Coin Cell Battery CR2032 3V Coin Cell Battery Holder LDR sensor BC547 transistor Buzzer 9V Battery Battery connector 10K resistor Connecting wires Cardboard or base board Laser Connections Connect coin cell holder positive to laser red wire. Connect coin cell holder negative to laser black wire. Insert the 3V coin cell battery. Laser will turn ON. Fix laser on one side of the model. Circuit Connections Hold BC547 transistor with flat side facing you. Left pin Collector Middle pin Base Right pin Emitter Emitter connect to battery negative. Collector connect to buzzer negative. Buzzer positive connect to battery positive. One LDR leg connect to battery positive. Other LDR leg connect to transistor base. Connect 10K resistor between base and battery negative. Working Laser light falls on the LDR sensor continuously. When laser light falls on LDR the buzzer remains OFF. When someone blocks the laser beam the buzzer turns ON. Testing Turn ON laser. Laser must fall directly on LDR. Buzzer should be OFF. Put hand between laser and LDR. Buzzer will start sounding. Applications Home security system Door security Bank security Museum security Precautions Do not look directly into laser light. Fix laser properly. Keep wiring tight. Align laser properly with LDR.