Design And Construction Of An Automatic Night Lamp Using Transistor

ABSTRACT

This work is on auto night lamp using high power LED. An Automatic Night Lamp Using High Power LEDs is a circuit which turns ON the LED lights interfaced to it at night time and it turns OFF the lights automatically when it is day.

This project discuses the working of turning on or off of high power LEDs with light intensity. The element which is used for sensing light in the circuit is the light dependent resistor. The resistance of the light dependent resistor depends on the light incident on it. If the intensity of light incident on it is more, then the resistance of the circuit decreases. If the intensity of light incident on it decreases, then the resistance of the device increases. We are making use of this property of the light dependent resistor to detect the light and thereby operate the LEDs.

TABLE OF CONTENTS

COVER PAGE

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWELDGEMENT

ABSTRACT

CHAPTER ONE

• INTRODUCTION
• BACKGROUND OF THE PROJECT
• AIM OF THE PROJECT
• OBJECTIVE OF THE PROJECT
• PURPOSE OF THE PROJECT
• SCOPE OF THE PROJECT
• SIGNIFICANCE OF THE PROJECT
• PROBLEM OF THE PROJECT
• LIMITATION OF THE PROJECT
• APPLICATION
• METHODOLOGY
• PROJECT ORGANISATION

CHAPTER TWO

LITERATURE REVIEW

• REVIEW OF LIGHT SENSOR
• LDR STRUCTURE AND WORKING
• REVIEW OF THE MAJOR COMPONENTS USED

CHAPTER THREE

METHODOLOGY

• SYSTEM BLOCK DIAGRAM
• SYSTEM CIRCUIT DIAGRAM
• OPERATION OF THE SYSTEM
• CIRCUIT DESCRIPTION

CHAPTER FOUR

4.0      TEST AND RESULT ANALYSIS

• CONSTRUCTION PROCEDURE AND TESTING ANALYSIS
• CASING AND PACKAGING
• ASSEMBLING OF SECTIONS
• TESTING OF SYSTEM OPERATION
• INSTALLATION OF THE COMPLETED DESIGN

CHAPTER FIVE

• CONCLUSION
• RECOMMENDATION
• REFERENCE

CHAPTER ONE

1.0                                                        INTRODUCTION

1.1                                           BACKGROUND OF THE STUDY

Automatic Night Lamp is a simple yet powerful concept, which uses transistor as a switch. By using this system manual works are 100% removed. It automatically switches ON lights when the sunlight goes below the visible region of our eyes. This is done by a sensor called Light Dependant Resistor (LDR) which senses the light actually like our eyes. It automatically switches OFF lights whenever the sunlight comes, visible to our eyes and activates the morning alarm. By using this system energy consumption is also reduced because nowadays the manually operated street lights are not switched off even the sunlight comes and also switched on earlier before sunset. In this project, no need of manual operation like ON time and OFF time setting. LDR and transistor are the main components of the project. The resistance of light dependant resistor (LDR) varies according to the light falling on it. This LDR is connected as biasing resistor of the transistor. According to the light falls on the LDR, the transistor is operated in saturation and cut off region. This transistor switches the relay to switch on / off the light. This project uses regulated 12V, 750mA power supply. 7812 three terminal voltage regulator is used for voltage regulation. Bridge type full wave rectifier is used to rectify the ac out put of secondary of 230/18V step down transformer.

1.2                                                   AIM OF THE PROJECT

The objective of this work is to build a circuit which turns ON the LED lights interfaced to it at night time and it turns OFF the lights automatically when it is day.

1.3                                             OBJECTIVE OF THE PROJECT

At the end of this work, students involved will be able to:

1. Build this device
2. know the connection, working principle and functions of light dependent resistor.

1.4                                              PURPOSE OF THE PROJECT

The purpose of this work is to have an automatic means of switching night light. The system turns ON the LED lights at night time and it turns OFF the lights automatically when it is day.

1.5                                                  SCOPE OF TH PROJECT

This circuit automatically turns on a night lamp when bedroom light is switched off. The lamp remains ‘on’ until the light sensor senses daylight in the morning. A super-bright white LED is used as the night lamp. It gives bright and cool light in the room. When the sensor detects the daylight in the morning, a melodious morning alarm sounds.

1.6                                         SIGNIFICANCE OF THE PROJECT

This device is very useful in that it distinguishes daylight and dark hours. This device eliminates the need of switching the Porch lamp or Backyard lamp daily and also helps to switch ON or OFF the premises of the house when the occupants are out of station.

1.7                                            PROBLEMS OF THE PROJECT

One of the problems of this device is that any opaque material can trigger the device, such as human shadow, movement of animals or ants across the sensor can trigger the system.

1.8                                           LIMITATION OF THE PROJECT

Project uses regulated 12V, 750mA power supply. 7812 three terminal voltage regulator is used for voltage regulation. Bridge type full wave rectifier is used to rectify the ac out put of secondary of 230/18V step down transformer.

The circuit also uses LEDs as lamp. Usage of LEDs is growing day by day due to the advantages they provide compared to the conventional filament bulbs or fluorescent lamps. They provide good quality of white light with a better intensity compared to others. They also consume less power compared to their alternatives. These are the advantages which the LEDs encourage us to use them compared to their alternatives. And transistors are used as switch.

1.9                                         APPLICATIONS OF THE PROJECT

• Useful for automatic outdoor lighting or garden lighting at home.
• Useful for automatic switching of street lights.
• Useful for switching the hoardings on and off automatically.
• Useful for self-switching operation of displaying title hoardings of companies.
• Useful as a light detector circuit when the pin of the ic is reconfigured.
• Useful as a dark activated switch.

1.10                                       METHODOLOGY

To achieve the aim and objectives of this work, the following are the steps involved:

1. Study of the previous work on the project so as to improve it efficiency.
2. Draw a block diagram.

• Test for continuity of components and devices,

1. Design of the device was carried out.
2. Studying of various component used in circuit.
3. Construction of the circuit was carried out. The construction of this project includes the placing of components on Vero boards, soldering and connection of components,

• Finally, the whole device was cased and final test was carried out.

1.11                                      PROJECT WORK ORGANISATION

The various stages involved in the development of this project have been properly put into five chapters to enhance comprehensive and concise reading. In this project thesis, the project is organized sequentially as follows:

Chapter one of this work is on the introduction to automatic night lamp. In this chapter, the background, significance, objective limitation and problem of dark activated alarm were discussed.

Chapter two is on literature review of automatic night lamp. In this chapter, all the literature pertaining to this work was reviewed.

Chapter three is on design methodology. In this chapter all the method involved during the design and construction were discussed.

Chapter four is on testing analysis. All testing that result accurate functionality was analyzed.

Chapter five is on conclusion, recommendation and references.

CHAPTER TWO

2.0                                                    LITERATURE REVIEW

2.1                                              REVIEW OF LIGHT SENSOR

There are different types of light sensors available, but for better efficiency of the system, LDR (Light Dependent Resistor) is used as sensor light switch in this light activated switch. The LDR sensor has some special features as it changes its resistance with the change in the daylight intensity. LDR is rugged in nature, hence can be used even in dirty and rough external environments like outdoor lighting of homes and in automatic street lights as well…