Introduction

An Automatic Street Light is an intelligent lighting system that turns street lights ON and OFF automatically based on ambient light conditions. It helps in reducing electricity consumption and minimizes the need for manual operation.

This project uses light sensors to control street lighting efficiently.

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Objective of the Project

The objectives of this project are:

• To automatically control street lights based on light intensity.
• To save electrical energy.
• To reduce manual intervention.
• To improve efficiency of public lighting systems.

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Working Principle

The system works on the principle of light detection using an LDR (Light Dependent Resistor).

Basic Operation

1. During daytime, the LDR senses high light intensity.
2. The resistance of LDR decreases and the circuit keeps the light OFF.
3. At night, light intensity decreases.
4. The LDR resistance increases.
5. The control circuit turns the street light ON automatically.

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Components Required

Basic Automatic Street Light

• LDR (Light Dependent Resistor)
• Comparator IC (LM358)
• Transistor / Relay
• Street Light (LED / Lamp)
• Resistors
• Potentiometer (10kΩ)
• Diode (1N4007)
• Power Supply (12V)

Arduino-Based Automatic Street Light

• Arduino Uno
• LDR
• Resistors
• Relay Module / LED
• Jumper wires

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Circuit Diagram

Basic Circuit

LDR ---> Comparator ---> Relay ---> Street Light

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Arduino-Based Circuit

LDR ---- A0
Relay -- D8
Light -- Relay Output
GND ---- Common Ground

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Arduino Code (Optional)

int ldrPin = A0;
int relayPin = 8;

void setup() {
  pinMode(relayPin, OUTPUT);
}

void loop() {
  int ldrValue = analogRead(ldrPin);

  if (ldrValue < 400) { // Night condition
    digitalWrite(relayPin, HIGH); // Light ON
  } else {
    digitalWrite(relayPin, LOW);  // Light OFF
  }

  delay(500);
}

Code Explanation

• Arduino reads light intensity from LDR.
• When it is dark, the street light turns ON.
• When sufficient light is present, the street light turns OFF.
• Threshold value can be adjusted.

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Advantages

• Energy efficient
• Automatic operation
• Low maintenance
• Cost-effective

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Applications

• Street lighting systems
• Highways and roads
• Parking areas
• Smart cities
• Campus lighting

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Conclusion

The Automatic Street Light project is a smart and eco-friendly solution for public lighting systems. It reduces power consumption and human effort while improving safety. This project can be further enhanced by integrating motion sensors or IoT-based monitoring.

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