This article is for simple Laser Light Alarm Circuit using Arduino. A laser light shines on an LDR. When someone blocks the laser beam, the LDR changes its value. Arduino reads this change and turns ON the buzzer to make alarm sound. A reset button stops the alarm. The system is low cost and easy […]
LDR Circuits
Laser Security Alarm Circuit using LDR and BC547 Transistors
This project is for Laser Security Alarm Circuit using LDR and BC547 Transistors. It uses LDR, two BC547 transistors, one diode and a buzzer. When laser light breaks an alarm rings. Circuit is cheap and very easy to build. Good for door security, box security and drawer protection. Circuit Working: Parts List: Component Value Quantity […]
Automatic Street Light Circuit using Arduino
This project for Automatic Street Light Circuit using Arduino how street light can think smart. Light will turn ON when night come. Light will turn OFF when sun come. No need of a human to press switch. Arduino and LDR do all work automatic. It save power and make street more smart. Simple idea but […]
Smart Street Light Control Circuit
Light ON at night and light OFF in day all automatic! All this is done with one LDR and a BC547 transistor. This Smart Street Light Control Circuit is a easy and simple way to save energy. There is no manual effort and no energy waste. Circuit Working: Parts List: Component Name Specification Quantity Resistors […]
LDR Based Dark Sensor Circuit
This small LDR Based Dark Sensor Circuit is very smart. It can see light and dark using LDR. When there is light, everything stay quiet. When it becomes dark then LED start to glow and buzzer makes sound. No need to touch anything it works by itself. It is easy to make with low cost […]
Automatic Light Control Circuit using LDR and LM3909 IC
This Automatic Light Control Circuit using LDR and LM3909 IC is small and smart light sensor circuit. It can feel light and dark like magic. It uses one LDR and one LM3909 IC. When dark come, LED turns ON. When light come, LED goes OFF. It is perfect for night lamps or auto lights. Circuit […]





