ABSTRACT
A light detector is used to detect the
presence of light in a particular area where it is placed, on detection of
light (either sunlight or illumination from LEDs) it gives a notification to
confirm the presence of light, this notification is based on the design or
purpose as the case may be (either raising an alarm or activating another
circuit or device). This device is
applicable in areas like fire detection, solar tracking, automatic garden light
control, street light control and mostly in the solar world. A LDR (light
dependent resistor) light sensor is a variable resistor. In this case we use a
pull-up resistor (which means that it is located before the sensor).
TABLE
OF CONTENTS
Pages
Title
page i
Certification ii
Dedication iii
Acknowledgment iv-v
Abstract vi
Table of contents vii-ix
CHAPTER
ONE
1.0 INTRODUCTION 1
1.1 BACKGROUND OF THE STUDY 2
AIMS
AND OBJECTIVES
1.2 AIMS OF THE PROJECT 2
1.3 OBJECTIVE
OF THE PROJECT 5
1.4 SCOPE
OF THE PROJECT 6
CHAPTER TWO
2.0 LITERATURE
REVIEW 7
TYPES
OF LIGHT DETECTORS
2.1.0 PHOTO TRANSISTOR 9
2.1.1 AVALANCHE PHOTO DIODE 11
2.1.2 PHOTO
MULTIPLIER TUBE 13
2.1.3 OPTICAL
HETERODYNING 16
2.1.4 FUTURE
DETECTORS 18
2.1.5 DETECTOR
NOISE 19
2.1.6 MINIMUM
DETECTABLE LIGHT LEVELS 22
2.1.7 LIGHT
DEPENDENT RESISTOR 23
2.1.8 PHOTO RESISTOR OR LIGHT DEPENDENT RESISTOR (LDR) 25
2.1.9
APPLICATIONS OF LDR 28
CHAPTER
THREE: METODOLOGY
3.0
MODE OF OPERATION OF A LIGHT DETECTOR 29
3.1 POWER SUPPLY STAGE 30
3.2 THE LIGHT SENSING SECTION 32
3.3
RECOVERY RATE 32
3.4
PROJECT TESTING 33
3.5 ASTABLE TIMER/ ALARM STAGE 34
3.6 BLOCK
DIAGRAM EXPLANATION 36
CHAPTER FOUR
4.0 OVERVIEW 38
4.1 LIGHT DEPENDENT RESISTOR 38
4.2
COMPONENTS USED (LIGHT DETECTOR) 41
CHAPTER
FIVR
5.0 SUMMARY, CONCLUSION AND RECOMMENDATION 42
5.1 SUMMARY 42
5.2 CONCLUSION 43
5.3 RECOMMENDATION 43
REFERENCES 45-46
CHAPTER
ONE
1.0 INTRODUCTION
Automatic Streetlight needs no
manual operation for switching ON and OFF when there is need of light. It
detects itself weather there is need for light or not. When darkness rises to a
certain value then automatically streetlight is switched ON and when there is
other source of light i.e. day time, the street light gets OFF. The
sensitiveness of the street light can also be adjusted. In our project we have
used four L.E.D for indication of bulb but for high power switching, one can
connect Relay (electromagnetic switch) at the output of pin 1 of I.C LM358 Then
it will be possible to turn ON/OFF any electrical appliances connected all the
way through relay. Detecting light has many uses in the world of robotics. We
use light detection in many of our competitions to find markers that lead us
around the course or to identify a burning fire that we can put out. This
article will cover how to make a few simple light detection circuits for you
a.
BACKGROUND
OF THE STUDY
We conducted a background
study through interviews with two key informants.
These two Interviews provided
us with a comparison of various forms of light sensor usage on campus.
Discovering
information regarding light sensor use in a place that we spend much of our
time truly allowed us to understand the considerations to be made much better.
AIMS
AND OBJECTIVES
1.2 AIMS OF THE PROJECT
This
project aims at designing and executing the advanced development in embedded
systems for energy saving of street lights with light depending resistor.
Nowadays, human beings have become too busy to that they are unable to find
time even to switch the lights wherever it’s necessary. This can be seen more
effectively in the case of street lights. The present system is like, the
street lights will be switched on in the evening before the sun sets and they
are switched off the next day morning after there is sufficient light on the
roads. But the actual timings for these street lights to be switched on are
when there is absolute darkness. With this, the power will be wasted up to some
extent. This project gives the best solution for electrical power wastage. Also
the manual operation of the lighting system is completely eliminated.
In
our project we are using LDR, which varies according to the amount of light
falling on its surface, this give an indication for us whether it is a
day/night time. We have placed IR sensors in both sides of the road, which can
be controlled by Micro controller (AT89C51).The IR‘s will be activated only on
the night time. If any obstacle crosses the IR, automatically particular light
will be ON, for few seconds.
In
our project we use regulated 5V, 500mA power supply. 7805 three terminal
voltage regulator is used for voltage regulation. Bridge type full wave
rectifier is used to rectify the ac output of secondary of 230/12V step down
transformer.
The
programming language used for developing the software to the microcontroller is
Embedded/Assembly. The KEIL cross compiler is used to edit, compile and debug
this program. Here in our application we are using AT89C51 microcontroller
which is Flash Programmable IC.AT represents the Atmel Corporation ‘C’
represents CMOS technology is used for designing the IC.
We believe that our idea provides better than
the existing system.
In the present project street lights are taken into consideration where the
above discussed factors are rectified in them. This is achieved with the help
of an embedded system. By using this as the basic principle we can design
centralized intelligent system for the perfect usage of streetlights in any
place (Via Village, Town) can be developed.
1.3 OBJECTIVE OF THE PROJECT
The main consideration in the
present field technologies are Automation, Power consumption and cost
effectiveness. Automation is intended to reduce man power with the help of
intelligent systems. Power saving is the main consideration forever as the
source of the power(Thermal, Hydro etc.,)are getting diminished due to various
reasons.
The main aim of the project is
Automatic street power saving system with LDR; this is to save the power. We
want to save power automatically instead of doing manual. So it’s easy to make
cost effectiveness. This saved power can be used in some other cases. So in
villages, towns etc we can design intelligent systems for the usage of street
lights.
The
guiding objectives of this study were:
·
To determine social beliefs and concerns
regarding light sensor usage.
·
To determine the economic feasibility of
installing light sensors.
1.4 SCOPE OF THE PROJECT
The
main scope of the project is to learn the picture microcontroller, using 10BIT
ADC serial communication, interfacing the 16x2 LCD module, and effective use of
the MIKROC IDE.
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