AUTOMATIC STREET LIGHT CONTROLLER

BY:Rajat Sood

1101500043

TABLE OF CONTENTSSr. No. Contents

Ch.1 Introduction

Ch.2 Circuit diagram

Ch.3 ComponentsUsed

Ch.4 Layout

Ch.5 Working

Ch.6 Advantages

Ch.7 Applications

INTRODUCTIONAutomatic Street Light Control System is a

simple yet powerful concept, which uses transistor as a switch. By using this system manual works are removed.

By using this system energy consumption is also reduced. the manual operation of the lighting system is completely eliminated.

By using the LDR we can operate the lights, i.e. when the light is available then it will be in the OFF state and when it is dark then the light will be in ON state, it means LDR is inversely proportional to light

CIRCUIT DIAGRAM

LAYOUT

COMPONENTS USEDCOMPONENETS

QUANTITY TYPE

1. LDR 1

2. Transistor 2 BC107,SL100

3. Resistor 2 R1=1k,R2=1k

4. Relay 1 SPDT

5. Preset 1 100k

WORKING The circuit diagram present here is that of a street light

that automatically switches ON when the night falls and turns OFF when the sun rises.

The circuit uses a LIGHT DEPENDENT RESISTOR (LDR)to sense the light When there is light the resistance of LDR will be low. So the voltage drop across POT R2 will be high . This keeps the transistor Q1 ON. The collector of Q1(BC107) is coupled to base of Q2(SL100). So Q2 will be OFF and so do the relay. The bulb will remain OFF.

When night falls the resistance of LDR increases to make the voltage across the POT R2 to decrease below 0.6V. This makes transistor Q1 OFF which in turn makes Q2 ON. The relay will be energized and the bulb will glow.

ADVANTAGESBy using this Automatic system for street

light controlling, we can reduce energy consumption because the manually operated street lights are not switched off properly even the sunlight comes and also not switched on earlier before sunset. 

In sunny and rainy days, ON  and OFF time differ noticeably which is one of the major disadvantage of using timer circuits or manual operation for switching the street light system.

APPLICATIONSCan be used in homes as a night lamp by

using bulb of small wattage.As the name suggests this can be used in

street lights where it is difficult to reach like mountaineous regions.