Smart Street Light Control System using 555 Timer IC, LDR, and Relay

This repository contains the implementation of a Smart Street Light Control System using a 555 Timer IC, Light-Dependent Resistor (LDR), and a Relay. The system uses an LDR (light dependent resistor) to detect the ambient light level and turn on the street lights when it gets dark. The 555 timer IC acts as a comparator circuit, with pin 6 connected to the positive supply voltage and pin 2 connected to the LDR. When the ambient light level falls below a certain threshold, the output of the 555 timer goes low, triggering the relay to turn on the street lights. The system can be easily used to control higher AC/DC loads by adding a relay with the LED at the output of the 555 timer.

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MINI PROJECT Keynotes:

1. This is electronic product design workshop with a focus on electronic circuit design.

2. The mini project may be a complete hardware or a combination of hardware and software. The software part in mini project should be less than 50% of the total work.

3. Mini Project should cater to a small system required in laboratory or real life.

4. It should encompass components, devices, analog or digital ICs, micro controller with which functional familiarity is introduced.

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Hardware Required

Component	Value/Specs	Quantity
Timer IC	NE555	1
LDR	-	1
Diode	1N4007	2
Resistor	1KΩ	2
Resistor	100KΩ	2
Resistor	2.2MΩ	1
Relay	5V	1
Battery	9V	1

Circuit Diagram

Circuit Simulation

To simulate and test the circuit, you can use Proteus Software, a popular electronic circuit simulation software. The circuit design for this project has been created in Proteus, and you can find the Proteus simulation file at the following location:

Proteus Circuit Simulation File

You can open the Proteus file in Proteus software and simulate the circuit to observe its behavior under different light conditions.

Demonstration

Circuit Configuration

The circuit configuration consists of an 8-pin 555 timer IC, with pins assigned specific functions. Here's a breakdown of the connections:

• Pin 5 and Pin 7: Connected by a 100k resistor, which pulls Pin 5 to ground. Pin 7 is connected to the collector of a PNP transistor inside the 555 timer, which is also connected to ground. This setup provides a reference voltage for the 555 timer's Comparator 1.
• Pins 8 and 6: Connected to the power supply (Vcc), ensuring stable voltage levels for proper operation.
• Pin 4: Connected to the ground, which is Reset low.
• Pin 1: Connected to the ground,establishing the common ground reference for the circuit.
• Pin 2: To detect the intensity of ambient light, a Light-Dependent Resistor (LDR) is used. The LDR is connected in series with a 100k resistor, forming a voltage divider circuit. This voltage divider circuit is connected to pin 2 (trigger input) of the 555 timer IC via a 2.2 M ohm resistor.
• Pin 3: Output of the circuit. High during Day, Low during Nighttime.

Functionality

The Smart Street Light Control System operates as follows:

1. During nighttime:

   • When the ambient light level falls below a certain threshold, the resistance of the LDR increases.
   • This causes an increase in the voltage at the junction of the LDR and the 100k resistor, triggering the 555 timer IC.
   • The 555 timer IC turns pin 3 (output pin) low, which is connected to the cathode of the red LED. The anode of the red LED is connected to Vcc.
   • The red LED illuminates and activates the relay, providing the required lighting for the street lights during nighttime. The relay also includes a 1n4007 flyback diode for surge protection.

2. During daylight hours:

   • When the ambient light intensity increases, the resistance of the LDR decreases.
   • This reduces the voltage at the junction of the LDR and the 100k resistor, deactivating the 555 timer IC.
   • The output pin 3 of the 555 timer IC turns high, indicating that the street lights are off.
   • A blue LED, with its anode connected to pin 3 and cathode to ground, is activated, indicating the state of the street lights.

Please refer to the circuit diagram and demonstration image provided in this repository for a visual representation of the setup.

Project Group Members

1. Ankit
2. Meheli
3. Souvik
4. Arnab

License

This project is licensed under the MIT License.