Solar Tracker (1)

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SOLAR TRACKER

A PROJECT REPORT

GAUTAM BUDDHA TECHNICAL UNIVERSITY

By

PARUL MALHOTRA (0935231040)

RASHI BAJPAI (0935231053)

RICHA SHARMA (0935231054)

RISHU SHUKLA (0935210045)

SONAL TRIPATHI (0932531076)

in partial fulfillment for the award of the degree

Of

BACHELOR OF TECHNOLOGY

In

ELECTRONICS & COMMUNICATION ENGINEERING

DEPARTMENT OF ELECTRONICS & COMMUNICATION ENGINEERING

KRISHNA GIRLS ENGINEERING COLLEGE BHAWANIPUR,

MANDHANA,

KANPUR, INDIA.

JUNE 2013


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CERTIFICATE

This is to certify that the project report entitled SOLAR TRACKER, submitted by

PARUL MALHOTRA (0935231040), RASHI BAJPAI (0935231053), RICHA

SHARMA (0935231054), RISHU SHUKLA (0935210045) , SONAL TRIPATHI

(0935231076) to the Uttar Pradesh Technical University Lucknow, in partial

fulfillment for the award of Degree of Bachelor of Technology in Electronics &

Communication Engineering is a bonafide record of the project work carried out by them

under my supervision during the year 2012-2013.

Rajan Verma Sumit Gupta

Head Department of EC (Project Guide)


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ACKNOWLEDGEMENT

It is our pleasure to acknowledge ELECTRONICS AND COMMUNICATION

DEPARTMENT, for giving us the opportunity and allowing us to do our final

project. We extend our sincere gratitude to our HOD, Mr. RAJAN VERMA,

who provided us all the lab facilities and steered in the right direction for

completing this assignment.

We sincerely convey our gratitude to our project guide Mr. SUMIT GUPTA

(Lecturer, ECE Deptt), whose continuous support and encouragement helped us to

complete our project.

We are also thankful to all the faculty and supporting staff who provided us

with adequate data information and help in spite of their hectic schedule.

Finally and most significantly we are indebted and deeply grateful to our parents

for their love, sacrifice, inspiration and valuable help that enable us to complete

this assignment.

Date:

Place: Kanpur

Parul Malhotra (0935231040)Rashi Bajpai (0935231053)Richa Sharma (0935231054)

Rishu Shukla (0935210045)

Sonal Tripathi (0935231076)

B.TECH. 4th

Year (EC)

KGEC Kanpur


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ABSTRACT

With the alarming rate of depletion of the major energy resources worldwide, it

has become an urgent necessity to seek for renewable energy resources that will

power the future. According to the worldwide market economy, the increasing

demand for energy had forced to put a huge price tag on natural combustible

sources of energies. In fact, it has been predicted that in the near future the

demand of energy will grow in such a rate that it will be completely impossible to

find out or meet the demand with the resources that we had been using for so

long, such as oil, gas, coal, etc. This issue throws a positive challenge to the

scientific community as more and more funds are being allocated for the research

and development of new alternatives.

The world is using up all the resources to meet the daily demands of energy and it

is quite expectable that in the near future we will run out of any naturally

occurring ore/mineral/petroleum. As a result, renewable energy solution has

achieved a great demand today to save the natural resources and also to tackle the

crisis of energy. Solar energy is rapidly gaining its popularity as an important

source of renewable energy.

But the efficiency of solar panel is a big factor. While the sun keeps following a

parabolic path throughout the day, the panels which are used in our country are

generally fixed to a pole or the roof of the house and hence, throughout the day,

the efficiency decreases significantly.

In this project, we have constructed a 2 axis solar tracker which can track the sun

throughout the day to obtain the maximum efficiency.


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TABLE OF CONTENTS

Title Page

Chapter 1. Introduction.............1

1.1 Energy......1

1.2 Motivation7

1.3 Solar Energy.8

1.4 Solar Energy Supply on Earth....10

1.5 Advantages of Solar Energy...12

1.6 Solar Tracker...14

Chapter 2. Literature Review..16

2.1 Hardware Specification of the System..17

2.1.1 Resistors.....17

2.1.2 Capacitors..20

2.1.3 Diodes24

2.1.4 Potentiometer.27

2.1.5 Light Dependent Resistor (LDR)...29

2.1.6 Light Emitting Diode (LED)..31

2.1.7 Crystal Oscillators..34

2.1.8 Sensors...36

2.1.9 Power Supply.39

2.1.10 Printed Circuit Board (PCB)..42

2.1.11 Regulators..45

2.1.12 Microcontroller..47

2.1.13 Global Positioning System (GPS)..48

2.1.14 Global System for Mobile Communication (GSM)...50

2.1.15 Radio Frequency Identification (RFID).51

Chapter 3. Project Description.53

3.1 Block Diagram53

3.2 Flow Chart..54


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3.3 Schematic Diagram55

3.4 Specific Components Used in Circuit56

3.4.1 Resistors.....56

3.4.2 Capacitors..58

3.4.3 Temperature Sensors......60

3.4.4 DC Geared Motor......61

3.4.5 Light Emitting Diode.....63

3.4.6 Zener Diode..... ..65

3.4.7 Voltage Regulator...67

3.4.8 Push Button.........68

3.4.9 USB Port.....69

3.4.10 Solar Panel...70

3.4.11 Light Dependent Resistor....71

3.4.12 IC used....73

3.4.12.1 L293D.....74

3.4.12.2 ATMEGA 8....76

3.5 Snapshot79

3.6 Working of Solar Tracker......80

3.6.1

Connection with USB Port...803.6.2 Light Dependent Resistor (LDR).80

3.6.3 Microcontroller81

3.6.4 L293D..82

3.6.5 DC Geared Motor82

3.6.6 Solar Panel...83

3.6.7 Rechargeable Battery...83

3.6.8 Graph Showing Variation of Outputs of TDR and Solar Tracker

..84

3.7 Basic Concept85

3.7.1 Solar Tracker.85

3.7.2 Types of Solar Tracker..........86

3.7.2.1Horizontal Axle Solar Tracker.86


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3.7.2.2Vertical Axle Solar Tracker.86

3.7.2.3Altitude Azimuth Solar Tracker..87

3.7.2.4Two Axis Mount Solar Tracker...88

3.7.2.5Multi Mirror Reflective Unit...88

3.7.2.6Active Tracker.89

3.7.2.7Passive Tracker89

3.7.2.8Chronological Tracker.89

3.7.3 Photoelectric Effect ..90

3.7.4 Emission Mechanism.....90

3.7.5 How Solar Cell generate Electricity..91

3.8 Source Code.93

Chapter 4..95

4.1 Advantages.95

4.2 Disadvantages.....96

4.3 Applications.....97

4.4 Future Scope....98

4.5 Conclusion...99

4.6 References.100


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List Of Figures

Figure Name Page

1.1 Mechanical Energy....1

1.2 Electrical Energy....2

1.3 Chemical Energy....2

1.4 Nuclear Energy...3

1.5 Hydro Energy......3

1.6 Solar Energy....4

1.7 Biomass Energy...5

1.8 Ocean & Tidal Energy.....5

1.9 Geothermal Energy..6

1.10 Wind Energy........6

1.11 Breakdown of Solar Energy.9

1.12 Utilization of Solar Energy....11

1.13 Gaseous Emission...12

1.14 Solar Barn...13

1.15 Solar Tracker..152.1 Characteristics of Resistor.17

2.2 Fixed Resistor.18

2.3 Variable Resistor.....18

2.4 Characteristics of Capacitor....20

2.5 Ceramic Capacitor...21

2.6 Film Capacitor.21

2.7 Electrolytic Capacitor......22

2.8 Super Capacitor....22

2.9 Variable Capacitor........23

2.10 Characteristics of Diode................24

2.11 LED.......24

2.12 Avalanche Diode.......25


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2.13 Laser Diode.....25

2.14 Schottky Diode....26

2.15 Potentiometer.......27

2.16 Characteristics of Potentiometer.......28

2.17 LDR......29

2.18 Characteristics of LDR......30

2.19 Characteristics of LED......31

2.20 Miniature LED.......32

2.21 High Power LED...33

2.22 Crystal Oscillator...34

2.23 Characteristics of Crystal Oscillator..35

2.24 Sensors...36

2.25 Optical Sensor....37

2.26 Microwave Sensor.37

2.27 Temperature Sensor...38

2.28 Power supply..39

2.29 Battery....40

2.30 Printed Circuit Board.....42

2.31

Single sided PCB...432.32 Double sided PCB..43

2.33 Multilayered...44

2.34 Battery Regulator...45

2.35 Pressure Regulator.....45

2.36 Dividing Regulator.46

2.37 Voltage Regulator..46

2.38 Microcontroller......47

2.39 Global Positioning System.48

2.40 GSM...50

2.41 Radio Frequency Identification..51

2.42 Radio Frequency Identification..52


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3.1 Block Diagram...53

3.2 Flowchart Showing Working of Solar Tracker..54

3.3 Schematic Of Solar Tracker...55

3.4 Some low power Resistors.....56

3.5 High power Resistors and Rheostats.56

3.6 Symbol of Resistors...57

3.7 Color coding of Resistor57

3.8 Capacitors..58

3.9 Electrolytic Capacitor....59

3.10 External Structure of DC Geared Motor....61

3.11 Lateral view of DC Geared Motor.....62

3.12 LED Characteristics...63

3.13 LED as an indicator...64

3.14 Symbol of Zener Diode..65

3.15 V-I Characteristics of Zener Diode65

3.16 Voltage Regulator 7805.67

3.17 Push Button....68

3.18 USB Port....69

3.19

Solar Panel.703.20 LDR...71

3.21 L293D....73

3.22 Pin Description...74

3.23 Pin Description of ATMEGA8..77

3.24 Solar Tracker..79

3.25 USB Cable.80

3.26 LDR, its internal structure & Stamplot of LDR....81

3.27 Master circuit.82

3.28 Audrino Circuit..82

3.29 L293D Circuit....82

3.30 DC Geared Motor..83

3.31 Solar Panel.....83


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3.32 Rechargeable Battery.84

3.33 Stamplot of TDR & Solar Tracker.84

3.34 Solar Tracker..85

3.35 Horizontal Axle Solar Tracker...86

3.36 Vertical Axle Solar Tracker...87

3.37 Altitude azimuth Solar Tracker..87

3.38 Two axis mount Solar Tracker...88

3.39 Multi mirror reflective unit88

3.40 Active Tracker...89

3.41 Photoelectric Effect.......91

3.42 Generation of electricity by Solar Tracker.....92


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CHAPTER 1:

INTRODUCTION

1.1 ENERGY

Energy is a crucial input in the process, social and industrial development. Energy

plays a vital role in our daily life. The degree of development and civilization of a

country is measured by the utilization of energy by human beings for their needs.

Day by day the energy consumption is increasing very rapidly. The worlds fossil-

fuel supply i.e, coal, petroleum and natural gas will be depleted in few hundred

years. The rate of energy consumption is increasing, supply is depleting resulting

in inflation and energy shortage. This is called the energy crisis.

Energy is available in different forms like

1. Mechanical energy: Mechanical energy is available in two forms: Kineticenergy and potential energy. The kinetic energy of a moving body is measured by

the amount of work which has been done in bringing the body from rest position

to its present position and vice-versa. The energy in a body due to its position is

called the potential energy.

Fig 1.1 Mechanical Energy


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2. Electrical Energy: In generator mechanical energy is very flexible andmultipurpose form of energy is electrical energy. It is clean, non-polluting, and

easily transportable form of energy.

Fig 1.2 Electrical Energy

3. Chemical Energy: In fuel cells, batteries, etc. chemical energy isconverted into electrical energy. Also during combustion of fuels the atoms-

carbon, hydrogen etc combine with oxygen with liberation of heat.

Fig 1.3 Chemical Energy


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4. Nuclear Energy: Uranium, plutonium and thorium isotopes are nuclearfuels. In their nuclei, the energy is released in the form of heat by nuclear fission

chain reaction.

Fig 1.4 Nuclear Energy

5. Hydro Energy: When water drops through a height, then its energyrotates the turbines which are coupled with alternator, which delivers the

electrical energy.

Fig 1.5 Hydro Energy


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The non conventional energy resourcesare:

1. Solar Energy: The earth receives the energy from Sun in the form ofelectromagnetic radiations. Solar energy is cheap and free from pollution.

Fig 1.6 Solar Energy

2. Bio-Gas and Bio-mass: Bio gas plant is a device for conversion offermentable organic matter, in particular cattle dung, into combustible gas and

fully matured organic manure. Biomass is organic matter derived from plants,

algae, animals, etc.


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Fig 1.7 Biomass Energy

3. Ocean Energy and Tidal Energy: The ocean contains the vast energypotential in its waves, in its tides and in the temperature difference between cold

deep waters and warm surface water.

Fig 1.8 Ocean and Tidal Energy


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4. Geothermal Energy: Geothermal energy is another energy source thatcan be harnessed for power generation and thermal applications in the near future.

Fig 1.9 Geothermal Energy

5. Wind Energy: Winds are caused by the pressure gradient. The kineticenergy of wind can be changed into mechanical or electrical energy.

Fig 1.10 Wind Energy


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1.2 MOTIVATION

With the rapid depletion of the natural resources of the world, we would soon

meet a great demand for alternative source of energy. In the very near future,

experts are predicting that we will be bound to move to renewable sources ofenergy, solar being one of them.

As long as our earth exists, the sun is there to give us unlimited solar energy. It is

completely up to us how we are going to utilize this abandoned energy. Every

hour, sun gives the same amount of energy to the world that the whole world uses

in an entire year.

Not only the world but our country is in a severe crisis of electricity. There are

many rural areas which are still deprived from the wonder of electricity. Due to

the geographical location of our country, we get sun almost 300 days a year.

Compared to many other countries like Canada and Norway, we are in a much

better location for utilizing solar energy. It can be used in areas where there is no

grid connection also.

Considering all the above things and the environmental friendliness, economically

sound and the ease of implementation, we thought of working on it as we believe

that in the near future, our country along with the whole world will be benefited

from this source of renewable energy.


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1.3 SOLAR ENERGY

Solar energy has the greatest potential of all the sources of renewable energy and

if only a small amount of this form of energy could be used, it will be one of the

most important supplies of energy specially when other sources in the countryhave depleted.

Energy comes to the earth from the sun. This energy keeps the temperature of the

earth above that in colder space, causes current in the atmosphere and in ocean,

causes the water cycle and generates photosynthesis in plants.

The solar power where sun hits atmosphere is 1017

watts, whereas the solar power

on earths surface is 1016

watts. The total world-wide power demand of all needs

of civilization is 1013

watts. Therefore, the sun gives us 1000 times more power

than we need.

The Earth receives 174 petawatts (PW) of incoming solar radiation (isolation) at

the upper atmosphere. Approximately 30% is reflected back to space while the

rest is absorbed by clouds, oceans and land masses. The spectrum of solar light at

the Earth's surface is mostly spread across the visible and near-infrared ranges

with a small part in the near-ultraviolet

Earth's land surface, oceans and atmosphere absorb solar radiation, and this raises

their temperature. Warm air containing evaporated water from the oceans rises,

causing atmospheric circulation or convection. When the air reaches a high

altitude, where the temperature is low, water vapor condenses into clouds, which

rain onto the Earth's surface, completing the water cycle. The latent heat of water

condensation amplifies convection, producing atmospheric phenomena such as

wind, cyclones and anti-cyclones. Sunlight absorbed by the oceans and land

masses keeps the surface at an average temperature of 14 C. By photosynthesisgreen plants convert solar energy into chemical energy, which produces food,

wood and the biomass from which fossil fuels are derived.

The total solar energy absorbed by Earth's atmosphere, oceans and land masses is

approximately 3,850,000 exajoules (EJ) per year. In 2002, this was more energy


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in one hour than the world used in one year. Photosynthesis captures

approximately 3,000 EJ per year in biomass. The technical potential available

from biomass is from 100300 EJ/year. The amount of solar energy reaching the

surface of the planet is so vast that in one year it is about twice as much as will

ever be obtained from all of the Earth's non-renewable resources of coal, oil,

natural gas, and mined uranium combined.

Solar energy can be harnessed at different levels around the world, mostly

depending on distance from the equator.

Fig 1.11 Breakdown of incoming Solar Energy


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1.4 SOLAR ENERGY SUPPLY ON EARTH

At the outer boundaries of the earths atmosphere, about 2.0 cal of energy

strikes, every minute, one square centimeter of the earths cross section. This is

the so called solar constant; its value means that about 1.25*10

24

cal of solarenergy are received anually by the earth as a whole. Only about 40 percent of this

energy, or 5*1020

Kcal, reaches the surface of earth. The rest is either absorbed by

the atmosphere or scattered into space

Despite these losses, if an economic method could be found to catch, store

and utilize the sunlight falling on our roof, it could easily cover all our domestic

energy needs, while sunlight falling on large open areas could easily run all the

wheels of human industry. Many attempts have been made to concentrate the

energy of sunlight, for example by means of giant concave mirrors, in order to

utilise it for industrial purposes; but only minor economic success have been

achieved so far.

It is also thoretically possible to convert light energy directly into

chemical energy, but as yet no effective and cheap way of doing this has beeen

found. The problem is not only to find a cheap photochemical system that would

store a substantial proportion of light absorbed in it; in addition, storage would

have to be in a convenient form, permitting easy removal of stored energy as

needed. The answer could be a light-produced explosive mixture, a light-produced

fuel, or a light-charged storage battery. None of these devices has been yet

developed successfully.

To satisfy its energy needs-foods, fuel, and industrial power-mankind now

depends almost entirely on plants. These organisms have solved the problem of

converting light energy into chemical energy with a rather low average yield, but

on a vast scale. Reserves of this energy, stored in past geological areas, areavailable to man as fossil fuels (coal, oil, peat). Amounts currently accumulated

by growing plants provide all human food (either directly, as vegetables, or

indirectly, as meat or milk or animals fed on plants) ; a small fraction of fuel is

provided in the same way, as wood or dung.


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The utilisation of energy stored by plants occurs by reversing

photosynthesis-rapidly, in furnaces and explosion motors, or slowly , in respiring

cells of plants and animals.

The plants store less than 1 percent of total solar energy reaching the

surface of earth. Man could easily live from this energy income of the earth, if we

are able to improve significantly on plants way to store it. One possible approach

is breeding more efficient plants; another is growing existing plants in a way that

would increase their natural rate of energy storage; the third is developing non

living systems for solar energy storage, as effective-and cheaper-than the present-

day solar batteries.

Fig 1.12 Utilization of Solar Energy


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1.5 ADVANTAGES OF SOLAR ENERGY

1. No green house gases: The first and foremost advantage of solar energy is that itdoes not emit any green house gases. Solar energy is produced by conducting the

suns radiation a process void of any smoke, gas, or other chemical by-product.This is the main driving force behind all green energy technology, as nations

attempt to meet climate change obligations in curbing emissions.

Fig 1.13 Gaseous Emissions

2. Infinite Free Energy: Another advantage of using solar energy is that beyondinitial installation and maintenance, solar energy is one hundred percent free.

Solar doesnt require expensive and ongoing raw materials like oil or coal, and

requires significantly lower operational labor than conventional power

production.

3. Decentralization of power:Solar energy offers decentralization in most (sunny)locations, meaning self-reliant societies. Oil, coal, and gas used to produce

conventional electricity is often transported cross-country or internationally.
http://exploringgreentechnology.com/http://exploringgreentechnology.com/


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4. Solar jobs: A particularly relevant and advantageous feature of solar energyproduction is that it creates jobs. The EIAA states that Europes solar industry has

created 100,000 jobs so far. Solar jobs come in many forms, from manufacturing,

installing, monitoring and maintaining solar panels, to research and design,

development, cultural integration, and policy jobs.

5. Solars avoidance of politics and price volatility:One of the biggest advantagesof solar energy is the ability to avoid the politics and price volatility that is

increasingly characterizing fossil fuel markets. The sun is an unlimited

commodity that can be adequately sourced from many locations, meaning solar

avoids the price manipulations and politics that have more than doubled the price

of many fossil fuels in the past decade.

6. Solar barn: Going off grid is a huge advantage of solar power for people inisolated locations. Solar energy can be produced on or off the grid. On grid means

a house remains connected to the state electricity grid. Off grid has no connection

to the electricity grid, so the house, business or whatever being powered is relying

solely on the solar orsolar-hybrid.The ability to produce electricity off the grid is

a major advantage of solar energy for people who live in isolated and rural areas.Power prices and the cost of installing power lines are often exorbitantly high in

these places and many have frequent power-cuts.

Fig 1.14 Solar Barn
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1.6 SOLAR TRACKER

Despite the unlimited solar energy, harvesting it is a challenged mainly because of

the inefficiency of the panels. Recent works shows that different types of

methodology have been proposed to improve the efficiency of solar panels.

Most of the panel installations that are done in our country are all fixed arrays. As

the day passes, the sun moves away from the facing position of the panel and thus

the power output of the panel decreases. The easiest way to overcome this

problem is to adapt a moveable solar panel using sun tracking mechanism. We

have adopted this system to improve the efficiency for photovoltaic cell

applications.

A solar tracker is a device for orienting solar photovoltaic panel towards the sun.

The suns position in the sky varies both with season and time of dayas the sun

moves across the sky. Solar powered equipment works best when pointed at or

near the sun, so the solar tracker can increase the effectiveness of such equipment

over any fixed position, at the cost of additional system complexity.

A solar tracker is a device that orients a payload toward the sun. Payloads can

be photovoltaic panels, reflectors, lenses or other optical devices.

In flat-panel photovoltaic (PV) applications, trackers are used to minimize the

angle of incidence between the incoming sunlight and a photovoltaic panel. This

increases the amount of energy produced from a fixed amount of installed power

generating capacity. In standard photovoltaic applications, it is estimated that

trackers are used in at least 85% of commercial installations greater than 1MW

from 2009 to 2012.

In concentrated photovoltaic (CPV) and concentrated solar thermal (CSP)

applications, trackers are used to enable the optical components in the CPV and

CSP systems. The optics in concentrated solar applications accept the direct

component of sunlight light and therefore must be oriented appropriately to

collect energy. Tracking systems are found in all concentrator applications

because such systems do not produce energy unless pointed at the sun.


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Fig 1.15 Solar Tracker

All the solar arrays that are currently being installed in our countries are fixed on

the rooftop or any favorable open space at approximately 230

inclination with the

surface. We went to BRAC Solar project and get to know that all the BRAC SolarHome System (SHS) are arranged in such a way that the battery will be charged

within 5 hours in a day and at night, the people can use the battery to run home

appliances accordingly. This seemed a lot inefficient since the sun in our country

is high up in the sky for around 104 hours every day. So with this system, 50% of

the sun energy are not being utilized and also this SHS does not allow the

consumers to use electricity during day time.

In many developed countries, solar trackers are already being used commercially.Importing and maintaining those in our country would be very expensive,

especially for the people in the rural areas who are the main consumers of solar

energy. So we thought of adopting the sun tracking mechanism to see how much

more energy we can utilize.


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CHAPTER 2:

LITERATURE REVIEW

Energy is a crucial input in the process of economic, social and industrial

development. Energy plays a vital role in our daily life. The degree of

development and civilization of a country is measured by the utilization of energy

by human beings for their needs. Energy is available in different forms like

electrical energy, mechanical energy, chemical energy, heat energy and nuclear

energy etc.

Day by day the energy consumption is increasing very rapidly. The worlds fossil

fuel supply i.e. coal petroleum and natural gas will be depleted in few hundred

years. The rate of energy consumption is increasing; supply is depleting resulting

in inflation and energy shortage. This is called the energy crisis. Alternative or

non-conventional or renewable energy resources are very essential to develop for

future energy requirements.

Energy can be extracted from various resources i.e. bio-energy, human energy,

mechanical energy, kinetic energy and animal energy.

Energy has many properties. According to law of conservation of energy Energy

can neither be created nor be destroyed but can be transformed from one

form to another form. Energy can be transported from one place to another

place.

The energy demand increases day by day because of increasing population,

increasing industrialization and inflation of means of transport etc.

To overcome with the problems of increasing demands of conventional energy the

use of non-conventional energy in more emphasized in this project. This is done

with the help of various technical equipments in order to save our conventional

resources.


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2.1HARDWARE SPECIFICATIONS OF THE SYSTEM2.1.1 RESISTORS:

A resistor is a passive two-terminal electrical component that implements

electrical resistance as a circuit element. The current through a resistor is in direct

proportion to the voltage across the resistor's terminals. This relationship is

represented by Ohm's law:

I=V/R

Where I is the current through the conductor in units of amperes, V is the

potential difference measured across the conductor in units of volts, and R is the

resistance of the conductor in units of ohms.

Fig 2.1 Characteristics Of Resistor

Types:

Resistors can be classified into two,

Fixed resistors:Fixed resistors are further classified into:

a) Carbon composition type resistors:This is the most common type of low

wattage resistor. The resistive material is of carbon-clay composition and

the leads are made of tinned copper.


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b) Wire wound resistors: These resistors are a length of wire wound an

insulating cylindrical core. Usually wires of material such as constantan

(60% copper and 40% nickel) and manganin which have high resistivities

and low temperature coefficients are employed.

c) Metalized resistors: It is constructed using film deposition techniques of

depositing a thick film of resistive material onto an insulating substrate.

Fig 2.2 Fixed Resistor

Variable resistors: For circuits requiring a resistance that can be adjusted

while it remains connected in the circuit, variable resistors are required.

Fig 2.3 Variable Resistor


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Applications: Many electrical devices are based on electrical resistance and

Ohm's law, even if they do not have little components in them that look like the

usual resistor. The following are some examples.

Lightbulb: It can be made by cutting a narrow waist into a metallic gumwrapper and connecting wrapper across the terminals of a 9-volt battery.

Polygraph: The polygraph, or "lie detector," is really just a set of meters

for recording physical measures of the subject's psychological stress, such

as sweating and quickened heartbeat.

Fuse: A fuse is a device inserted in a circuit tollbooth-style in the same

manner as an ammeter. It is simply a piece of wire made of metals having

a relatively low melting point.


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2.1.2 CAPACITORS:A capacitor (originally known as condenser) is a passive two-terminal electrical

component used to store energy in an electric field. The forms of practical

capacitors vary widely, but all contain at least two electrical conductors separatedby a dielectric (insulator); for example, one common construction consists of

metal foils separated by a thin layer of insulating film.

Fig 2.4 Characteristics of Capacitor

Types: Capacitors can be classified as :

Ceramic Capacitors:It is a non-polarized fixed capacitor made out of

two or more alternating layers of ceramic and metal in which the ceramic

material acts as the dielectric and the metal acts as the electrodes.


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Fig 2.5 Ceramic Capacitor

Film Capacitor: Film capacitors or plastic film capacitors are non-

polarized capacitors with an insulating plastic film as the dielectric. The

dielectric films are drawn to a thin layer, provided with metallic electrodes

and wound into a cylindrical winding.

Fig 2.6 Film Capacitor

Electrolytic capacitors: Electrolytic capacitors are polarized. Three

families are available, categorized according to their dielectric.

a). Aluminum electrolytic capacitors withaluminum oxide as dielectric

b). Tantalum electrolytic capacitors withtantalum pentoxide as dielectric

c). Niobium electrolytic capacitors withniobium pentoxide as dielectric.
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Fig 2.7 Electrolytic Capacitor

Super capacitors: Super capacitors, a new type of electrochemical

capacitor are also called ultra capacitors. Super capacitors are divided into

three families, according to the relative amounts of capacitance in the

double layers v/s pseudo capacitance:

a).Double-layer capacitors

b).Pseudocapacitors

c).Hybrid capacitors

Fig 2.8 Super Capacitor
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Variable Capacitors: Variable capacitors may have their capacitance

changed by mechanical motion. Two variable capacitors are:

a) Tuning capacitor variable capacitor for intentionally and repeatedly tuning

an oscillator circuit in a radio or another tuned circuit

b) Trimmer capacitor small variable capacitor usually for one-time

oscillator circuit internal adjustment.

Fig 2.9 Variable capacitor

Applications:

Capacitor has many uses in electronics and electrical system:

Energy storage: A capacitor can store electric energy when disconnected from

its charging circuit, so it can be used like a temporary battery.

Power Conditioning: Reservoir capacitors are used in power supplies where

they smooth the output of a full or half waverectifier.

Signal Processing: The energy stored in a capacitor can be used to represent

information,either in binary form, as in DRAMs,or in analogue form, as in

analog sampled filters andCCDs
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2.1.3 DIODESA diode is a two-terminal device, having two active electrodes, between which it

allows the transfer of current in one direction only. Diodes are known for their

unidirectional current property.

Fig 2.10 Characteristics of Diode

Types:

Light Emitting Diode (LED): It is one of the most popular type of diodes

and when this diode permits the transfer of electric current between the

electrodes, light is produced.

Fig 2.11 LED


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Avalanche Diode: This type of diode operates in the reverse bias, and

used avalanche effect for its operation. The avalanche breakdown takes

place across the entire PN junction, when the voltage drop is constant and

is independent of current.

Fig 2.12 Avalanche Diode

Laser Diode: This type of diode is different from the LED type, as it

produces coherent light. These diodes find their application in DVD and

CD drives, laser pointers, etc.

Fig 2.13 Laser Diode


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Schottky Diodes: These diodes feature lower forward voltage drop as

compared to the ordinary silicon PN junction diodes.

Fig 2.14 Schottky Diode

Applications:

Radio Demodulation: The diode (originally a crystal diode)rectifies the

AM radio frequency signal, leaving only the positive peaks of the carrierwave.

Power Conversion:Rectifiers are constructed from diodes, where they are

used to convertalternating current (AC) electricity intodirect current

(DC).
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2.1.4 POTENTIOMETERA potentiometer, informally a pot, is a three-terminalresistor with a sliding

contact that forms an adjustablevoltage divider. If only two terminals are used,

one end and the wiper, it acts as a variable resistor or rheostat.

Apotentiometer measuring instrument is essentially a voltage divider used for

measuringelectric potential (voltage); the component is an implementation of the

same principle.

Potentiometers comprise a resistive element, a sliding contact (wiper) that moves

along the element, making good electrical contact with one part of it, electrical

terminals at each end of the element, a mechanism that moves the wiper from one

end to the other, and a housing containing the element and wiper.

Fig 2.15 Potentiometer

Many inexpensive potentiometers are constructed with a resistive element formed

into an arc of a circle usually a little less than a full turn, and a wiper rotating

around the arc and contacting it. The resistive element, with a terminal at each
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end, is flat or angled. The wiper is connected to a third terminal, usually between

the other two.

Fig 2.16 Characteristics of Potentiometer

Applications:

Audio Control: Low-power potentiometers, both linear and rotary, are used to

control audio equipment, changing loudness, frequency attenuation and other

characteristics of audio signals.

Television: Potentiometers were formerly used to control picture brightness,

contrast, and color response. A potentiometer is often used to adjust "vertical

hold", which affected the synchronization between the receiver's internal

sweep circuits.

Transducer: Potentiometers are also very widely used as a part of

displacement transducers because of the simplicity of construction and

because they can give a large output signal.

Motion Control: Potentiometers can be used as position feedback devices in

order to create "closed loop" control, such as in a servomechanism.


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2.1.5 LIGHT DEPENDENT RESISTOR (LDR)A Photoresistor or a light dependent resistor (LDR) is

aresistor whoseresistance decreases with increasing incident light intensity; in

other words, it exhibitsphotoconductivity.

A photo resistor is made of a high resistancesemiconductor.If light falling on the

device is of high enoughfrequency,photons absorbed by the semiconductor give

boundelectrons enough energy to jump into theconduction band. The resulting

free electron (and its holepartner) conduct electricity, thereby

loweringresistance.

Fig 2.17 LDR

Extrinsic devices have impurities, also calleddo pants,added whose ground state

energy is closer to the conduction band; since the electrons do not have as far to

jump, lower energy photons (that is, longer wavelengths and lower frequencies)

are sufficient to trigger the device. If a sample of silicon has some of its atoms

replaced by phosphorus atoms (impurities), there will be extra electrons available

for conduction.
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Fig 2.18 Characteristics Of LDR

Applications:

Photo resistors come in many types. Inexpensive cadmium sulphide cells

can be found in many consumer items such as camera light meters, street

lights, clock radios,alarm devices,outdoor clocks, solar street lamps and

solar road studs, etc.

They are also used in some dynamic compressors together with a small

incandescent lamp orlight emitting diode to control gain reduction and are

also used in bed lamps, etc.

Lead sulphide (PbS) andindium antimonide (InSb) LDRs (light dependent

resistor) are used for the mid infrared spectral region. Ge:Cu

photoconductors are among the best far-infrared detectors available, and

are used forinfrared astronomy andinfrared spectroscopy.
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2.1.6 LIGHT EMITTING DIODE (LED)A light-emittingdiode (LED) is asemiconductor light source. LEDs are used as

indicator lamps in many devices and are increasingly used for other lighting.

Appearing as practical electronic components in 1962, early LEDs emitted low-intensity red light, but modern versions are available across the visible,

ultraviolet,andinfrared wavelengths, with very high brightness.

When a light-emitting diode is switched on,electrons are able to recombine with

holes within the device, releasing energy in the form of photons.This effect is

calledelectroluminescence and the color of the light (corresponding to the energy

of the photon) is determined by the energy band gap of the semiconductor. An

LED is often small in area (less than 1 mm2), and integrated optical components

may be used to shape its radiation pattern.LEDs present many advantages over

incandescent light sources including lower energy consumption, longer lifetime,

improved physical robustness, smaller size, and faster switching.

Fig 2.19 Characteristics Of LED
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Types:

The main types of LEDs are miniature, mid range and high power leds.

Miniature: These are mostly single-die LEDs used as indicators, and they

come in various sizes from 2 mm to 8 mm, through-hole and surface

mount packages. They usually do not use a separate heat sink. Typical

current ratings ranges from around 1 mA to above 20 mA. The small size

sets a natural upper boundary on power consumption due to heat caused

by the high current density and need for a heat sink.

Fig 2.20 Miniature LED

Mid-range: Medium-power LEDs are often through-hole-mounted and

mostly utilized when an output of just a few lumen is needed. They

sometimes have the diode mounted to four leads (two cathode leads, two

anode leads) for better heat conduction and carry an integrated lens. An

example of this is the Superflux package, from Philips Lumileds.

High-power: High-power LEDs (HPLED) can be driven at currents from

hundreds of mA to more than an ampere, compared with the tens of mA

for other LEDs. Some can emit over a thousand lumens. LED power
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densities up to 300W/cm2 have been achieved. Since overheating is

destructive, the HPLEDs must be mounted on a heat sink to allow for heat

dissipation.

Fig 2.21 High Power LED

Applications:

LED uses fall into four major categories:

Visual signals where light goes more or less directly from the source to the

human eye, to convey a message or meaning. Illumination where light is reflected from objects to give visual response

of these objects.

Measuring and interacting with processes involving no human vision.

Narrow band light sensors where LEDs operate in a reverse-bias mode and

respond to incident light, instead of emitting light.
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2.1.7 CRYSTAL OSCILLATORSA crystal oscillator is an electronic oscillator circuit that uses the mechanical

resonance of a vibrating crystal of piezoelectric material to create an electrical

signal with a very precise frequency.This frequency is commonly used to keeptrack of time (as in quartz wristwatches), to provide a stable clock signal for

digital integrated circuits, and to stabilize frequencies for radio transmitters and

receivers. The most common type of piezoelectric resonator used is the quartz

crystal, so oscillator circuits incorporating them became known as crystal

oscillators.

Quartz crystals are manufactured for frequencies from a few tens ofkilohertz to

tens of megahertz. More than two billion crystals are manufactured annually.

Most are used for consumer devices such as wristwatches, clocks, radios,

computers,andcellphones.

Fig 2.22 Crystal Oscillator

Acrystal is asolid in which the constituentatoms,molecules,orions are packed

in a regularly ordered, repeating pattern extending in all three spatial dimensions.

When a crystal ofquartz is properly cut and mounted, it can be made to distort in

anelectric fieldby applying avoltage to anelectrode near or on the crystal. This
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property is known aspiezoelectricity.When the field is removed, the quartz will

generate an electric field as it returns to its previous shape, and this can generate a

voltage. The result is that a quartz crystal behaves like a circuit composed of an

inductor,capacitor andresistor,with a precise resonant frequency.

Quartz has the further advantage that its elastic constants and its size change in

such a way that the frequency dependence on temperature can be very low. The

specific characteristics will depend on the mode of vibration and the angle at

which the quartz is cut.

Fig 2.23 Characteristics of Crystal Oscillator

Applications:

Military and Aerospace

Research and measurement

Industrial

Automotive

Consumer
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2.1.8 SENSORSA sensor (also called detector) is a converter that measures a physical quantity

and converts it into a signal which can be read by an observer or by an (today

mostlyelectronic)instrument.

Fig 2.24 Sensors

Types :

The various types of sensors are

Optical Sensors:

a) Visible/Near Infrared Remote Sensing: The observation method to acquire

visible light and near infrared rays of sunlight reflected by objects on the ground.

By examining the strength of reflection, we can understand a conditions of land

surface.

b) Thermal Infrared Remote Sensing: The observation method to acquire

thermal infrared rays, which is radiated from land surface heated by sunlight.
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Fig 2.25 Optical Sensors

Microwave Sensors: Microwave sensors receive microwaves, which is

longer wavelength than visible light and infrared rays, and observation is not

affected by day, night or weather.

a) Active type: The sensor aboard earth observation satellite emits

microwaves and observes microwaves reflected by land surface.

b) Passive type: This type observes microwaves naturally radiated from land

surface. It is suitable to observe sea surface temperature, snow accumulation,

thickness of ice.

Fig 2.26 Microwave Sensor


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Temperature Sensors: These sensors use a solid-state technique to

determine the temperature.

a) Mechanical temperature Sensors: Thermometer, bimetal.

b) Electrical Temperature Sensors: Thermister, thermocouple, resistance

thermometer.

Fig 2.27 Temperature Sensor

Applications:

In industry: On the factory floor, networked vibration sensors warn that a

bearing is beginning to fail.

For safety and security: Firefighters scatter wireless sensors throughout a

burning building to map hot spots and flare-ups.

In classroom: Sensor technology provides teachers with an exciting

alternative to the time consuming task of manually logging and observing science

experiments.

In education: Sensor technology provides students with a means of

seeing, interpreting, exploring and communicating relationships graphically.


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2.1.9 POWER SUPPLYA power supply is a device that supplieselectric power to anelectrical load.The

term is most commonly applied toelectric power converters that convert one form

of electrical energy to another, though it may also refer to devices that convertanother form of energy (mechanical, chemical, solar) to electrical energy. A

regulated power supply is one that controls the output voltage or current to a

specific value; the controlled value is held nearly constant despite variations in

either load current or the voltage supplied by the power supply's energy source.

Every power supply must obtain the energy it supplies to its load, as well as any

energy it consumes while performing that task, from an energy source. Depending

on its design, a power supply may obtain energy from:

Electrical energy transmission systems. Common examples of this include

power supplies that convertAC line voltage toDC voltage.

Energy storage devices such asbatteries andfuel cells.

Electromechanical systems such asgenerators andalternators.

Solar power.

Fig 2.28 Power Supply
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Types:

BATTERY: Battery is a device that converts stored chemical energy to electrical

energy. Batteries are commonly used as energy sources in many household and

industrial applications. There are two types of batteries: primary batteries

(disposable batteries), which are designed to be used once and discarded, and

secondary batteries (rechargeable batteries), which are designed to be recharged

and used multiple times.

Fig 2.29 Battery

DC POWER SUPPLY: AnACpowered unregulated power supply usually usesa transformer to convert the voltage from the wall outlet (mains) to a different,

nowadays usually lower, voltage.

AC power supply:An AC power supply typically takes the voltage from a wall

outlet (mains supply)and lowers it to the desired voltage. Some filtering may take

place as well.

Linear regulated power supply: The voltage produced by an unregulated powersupply will vary depending on the load and on variations in the AC supply

voltage.
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AC/DC supply: In the past, mains electricity was supplied as DC in some

regions, AC in others. Transformers cannot be used for DC, but a simple, cheap

unregulated power supply could run directly from either AC or DC mains without

using a transformer. The power supply consisted of a rectifier and a filter

capacitor.

Uninterruptible power supply:An uninterruptible power supply (UPS) takes its

power from two or more sources simultaneously. It is usually powered directly

from the AC mains, while simultaneously charging a storage battery. Should there

be a dropout or failure of the mains, the battery instantly takes over so that the

load never experiences an interruption.

High-voltage power supply: High voltage refers to an output on the order of

hundreds or thousands of volts. High-voltage supplies use a linear setup to

produce an output voltage in this range.

Voltage multipliers:A voltage multiplier is an electrical circuit that converts AC

electrical power from a lower voltage to a higher DC voltage, typically by means

of a network of capacitors and diodes. The input voltage may be doubled (voltage

doubler), tripled (voltage tripler), quadrupled (voltage quadrupler), and so on.

These circuits allow high voltages to be obtained using a much lower voltage AC

source.

Applications :

Computer Power Supply:A modern computer power supply is a switch-

mode power supply that converts AC power from the mains supply, to

several DC voltages.

Welding Power Supply:Arc welding uses electricity to melt the surfaces

of the metals in order to join them together through coalescence. The

electricity is provided by a welding power supply, and can either beAC or

DC.

AC Adapter: A power supply that is built into anAC mains power plug is

known as a "plug pack" or "plug-in adapter", or by slang terms such as

"wall wart".
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2.1.10 PRINTED CIRCUIT BOARD (PCB):A printed circuit board, or PCB, is used to mechanically support and electrically

connect electronic components using conductive pathways, tracks or signal traces

etched from copper sheets laminated onto a non-conductive substrate. When theboard has only copper tracks and features, and no circuit elements such as

capacitors, resistors or active devices have been manufactured into the actual

substrate of the board, it is more correctly referred to as printed wiring board

(PWB) or etched wiring board.

Fig 2.30 Printed circuit board

Types:

Single Sided Board: This is the least complex of the Printed Circuit

Boards, since there is only a single layer of substrate. All electrical parts

and components are fixed on one side and copper traces are on the other

side.


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Fig 2.31 single sided PCB

Double Sided Board: This is the most common type of board, where

parts and components are attached to both sides of the substrate.

Fig 2.32 Double Sided Board
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Multi Layered Board: Multi layered PCB consists of several layers of

substrate separated by insulation.

Fig 2.33 Multi layered

Applications:

Typical applications for Printed Circuits are as follows

General Electronics Products - includes consumer products, some

computer and computer peripherals, as well as general military hardware.

Dedicated Service Electronics Includes Communication Equipment,

sophisticated business machines, instruments and military equipment.

High Reliability Electronics Includes Military and Commercial

equipment where continued performance or performance on demand is

critical.


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2.1.11 REGULATORS:

Regulator is a device that maintains a designated characteristic, as in:

Battery Regulator:A battery balancer or battery regulator is a device in abattery

pack that performs battery balancing.

Fig 2.34 Battery regulator

Pressure Regulator :A pressure regulator is avalve that automatically cuts off

the flow of a liquid or gas at a certain pressure.

Fig 2.35 Pressure Regulator
http://en.wikipedia.org/wiki/Regulator_%28automatic_control%29http://en.wikipedia.org/wiki/Battery_packhttp://en.wikipedia.org/wiki/Battery_packhttp://en.wikipedia.org/wiki/Valvehttp://en.wikipedia.org/wiki/Valvehttp://en.wikipedia.org/wiki/Battery_packhttp://en.wikipedia.org/wiki/Battery_packhttp://en.wikipedia.org/wiki/Regulator_%28automatic_control%29


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Dividing Regulator : A diving regulator is apressure regulator used in

scuba or surface supplied diving equipment that reduces pressurized

breathing gas to ambient pressure and delivers it to the diver.

Fig 2.36 Dividing Regulator

Voltage Regulator: A voltage regulator is designed to automatically

maintain a constant voltage level. A voltage regulator may be a simple "feed-

forward" design or may includenegative feedbackcontrol loops.

Fig 2.37 Voltage Regulator
http://en.wikipedia.org/wiki/Pressure_regulatorhttp://en.wikipedia.org/wiki/Scuba_sethttp://en.wikipedia.org/wiki/Surface_supplied_divinghttp://en.wikipedia.org/wiki/Voltagehttp://en.wikipedia.org/wiki/Negative_feedbackhttp://en.wikipedia.org/wiki/Control_theoryhttp://en.wikipedia.org/wiki/Control_theoryhttp://en.wikipedia.org/wiki/Negative_feedbackhttp://en.wikipedia.org/wiki/Voltagehttp://en.wikipedia.org/wiki/Surface_supplied_divinghttp://en.wikipedia.org/wiki/Scuba_sethttp://en.wikipedia.org/wiki/Pressure_regulator


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2.1.12 MICROCONTROLLER :A microcontroller (sometimes abbreviated C, uC or MCU) is a small computer

on a single integrated circuit containing a processor core, memory, and

programmable input/output peripherals. Program memory in the form of NORflash or OTP ROM is also often included on chip, as well as a typically small

amount of RAM. Microcontrollers are designed for embedded applications, in

contrast to the microprocessors used in personal computers or other general

purpose applications.

Microcontrollers are used in automatically controlled products and devices, such

as automobile engine control systems, implantable medical devices, remote

controls, office machines, appliances, power tools, toys and other embedded

systems.

Fig 2.38 Microcontroller
http://en.wikipedia.org/wiki/Integrated_circuithttp://en.wikipedia.org/wiki/Input/outputhttp://en.wikipedia.org/wiki/NOR_flashhttp://en.wikipedia.org/wiki/NOR_flashhttp://en.wikipedia.org/wiki/Programmable_read-only_memoryhttp://en.wikipedia.org/wiki/Random-access_memoryhttp://en.wikipedia.org/wiki/Microprocessorhttp://en.wikipedia.org/wiki/Personal_computerhttp://en.wikipedia.org/wiki/Embedded_systemhttp://en.wikipedia.org/wiki/Embedded_systemhttp://en.wikipedia.org/wiki/Embedded_systemhttp://en.wikipedia.org/wiki/Embedded_systemhttp://en.wikipedia.org/wiki/Personal_computerhttp://en.wikipedia.org/wiki/Microprocessorhttp://en.wikipedia.org/wiki/Random-access_memoryhttp://en.wikipedia.org/wiki/Programmable_read-only_memoryhttp://en.wikipedia.org/wiki/NOR_flashhttp://en.wikipedia.org/wiki/NOR_flashhttp://en.wikipedia.org/wiki/Input/outputhttp://en.wikipedia.org/wiki/Integrated_circuit


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2.1.13 GLOBAL POSITIONING SYSTEM:The Global Positioning System (GPS) is a space-based satellite navigation

system that provides location and time information in all weather conditions,

anywhere on or near the Earth where there is an unobstructed line of sight to four

or more GPS satellites. The system provides critical capabilities to military, civil

and commercial users around the world. It is maintained by the United States

government and is freely accessible to anyone with aGPS receiver.

The GPS project was developed in 1973 to overcome the limitations of previous

navigation systems, integrating ideas from several predecessors, including a

number of classified engineering design studies from the 1960s.

Fig 2.39 Global Positioning System
http://en.wikipedia.org/wiki/Satellite_navigationhttp://en.wikipedia.org/wiki/GPS_receiverhttp://en.wikipedia.org/wiki/GPS_receiverhttp://en.wikipedia.org/wiki/Satellite_navigation


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Basic Concept: A GPS receiver calculates its position by precisely timing the

signals sent by GPS satellites high above the Earth. Each satellite continually

transmits messages that include

the time the message was transmitted

satellite position at time of message transmission

The receiver uses the messages it receives to determine the transit time of each

message and computes the distance to each satellite using the speed of light. Each

of these distances and satellites' locations define a sphere. The receiver is on the

surface of each of these spheres when the distances and the satellites' locations are

correct. These distances and satellites' locations are used to compute the location

of the receiver using the navigation equations. This location is then displayed,

perhaps with a moving map display or latitude and longitude; elevation

information may be included. Many GPS units show derived information such as

direction and speed, calculated from position changes.

Application:

Navigation: GPS allows soldiers to find objectives, even in the dark or in

unfamiliar territory, and to coordinate troop and supply movement

Target tracking: Various military weapons systems use GPS to track potential

ground and air targets before flagging them as hostile

Astronomy: Both positional and clock synchronization data is used in

Astrometry and Celestial mechanics calculations. It is also used in amateur

astronomy usingsmall telescopes to professionals observatories.

Cellular telephony: Clock synchronization enables time transfer, which is

critical for synchronizing its spreading codes with other base stations tofacilitate inter-cell handoff and support hybrid GPS/cellular position detection

formobile emergency calls and other applications.
http://en.wikipedia.org/wiki/Satelliteshttp://en.wikipedia.org/wiki/Global_Positioning_System#Navigation_equationshttp://en.wikipedia.org/wiki/Latitudehttp://en.wikipedia.org/wiki/Longitudehttp://en.wikipedia.org/wiki/Astronomyhttp://en.wikipedia.org/wiki/Clock_synchronizationhttp://en.wikipedia.org/wiki/Astrometryhttp://en.wikipedia.org/wiki/Celestial_mechanicshttp://en.wikipedia.org/wiki/Amateur_astronomyhttp://en.wikipedia.org/wiki/Amateur_astronomyhttp://en.wikipedia.org/wiki/GoTo_%28telescopes%29http://en.wikipedia.org/wiki/Cellular_telephonyhttp://en.wikipedia.org/wiki/E911#Wireless_enhanced_911http://en.wikipedia.org/wiki/E911#Wireless_enhanced_911http://en.wikipedia.org/wiki/Cellular_telephonyhttp://en.wikipedia.org/wiki/GoTo_%28telescopes%29http://en.wikipedia.org/wiki/Amateur_astronomyhttp://en.wikipedia.org/wiki/Amateur_astronomyhttp://en.wikipedia.org/wiki/Celestial_mechanicshttp://en.wikipedia.org/wiki/Astrometryhttp://en.wikipedia.org/wiki/Clock_synchronizationhttp://en.wikipedia.org/wiki/Astronomyhttp://en.wikipedia.org/wiki/Longitudehttp://en.wikipedia.org/wiki/Latitudehttp://en.wikipedia.org/wiki/Global_Positioning_System#Navigation_equationshttp://en.wikipedia.org/wiki/Satellites


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2.1.14 GLOBAL SYSTEM FOR MOBILE COMMUNICATION (GSM):GSM (Global System for Mobile Communications, originally Groupe Spcial

Mobile), is a standard set developed by the European Telecommunications

Standards Institute (ETSI) to describe protocols for second generation (2G)digitalcellular networks used bymobile phones.It became the de facto global standard

for mobile communications withover 80% market share.

The GSM standard was developed as a replacement for first generation (1G)

analog cellular networks, and originally described a digital, circuit switched

network optimized forfull duplex voicetelephony.This was expanded over time

to include data communications, first by circuit switched transport, then packet

data transport via GPRS (General Packet Radio Services) and EDGE (Enhanced

Data rates for GSM Evolution or EGPRS).

"GSM" is atrademark owned by theGSM Association.

Fig 2.40 GSM
http://en.wikipedia.org/wiki/European_Telecommunications_Standards_Institutehttp://en.wikipedia.org/wiki/European_Telecommunications_Standards_Institutehttp://en.wikipedia.org/wiki/2Ghttp://en.wikipedia.org/wiki/Cellular_networkhttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Comparison_of_mobile_phone_standardshttp://en.wikipedia.org/wiki/1Ghttp://en.wikipedia.org/wiki/Duplex_%28telecommunications%29#Full_duplexhttp://en.wikipedia.org/wiki/Telephonyhttp://en.wikipedia.org/wiki/GPRShttp://en.wikipedia.org/wiki/EDGEhttp://en.wikipedia.org/wiki/Trademarkhttp://en.wikipedia.org/wiki/GSM_Associationhttp://en.wikipedia.org/wiki/GSM_Associationhttp://en.wikipedia.org/wiki/Trademarkhttp://en.wikipedia.org/wiki/EDGEhttp://en.wikipedia.org/wiki/GPRShttp://en.wikipedia.org/wiki/Telephonyhttp://en.wikipedia.org/wiki/Duplex_%28telecommunications%29#Full_duplexhttp://en.wikipedia.org/wiki/1Ghttp://en.wikipedia.org/wiki/Comparison_of_mobile_phone_standardshttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Cellular_networkhttp://en.wikipedia.org/wiki/2Ghttp://en.wikipedia.org/wiki/European_Telecommunications_Standards_Institutehttp://en.wikipedia.org/wiki/European_Telecommunications_Standards_Institute


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2.1.15 RADIO FREQUENCY IDENTIFICATION(RFID):Radio-frequency identification (RFID) is the wireless non-contact use of radio-

frequency electromagnetic fields to transfer data, for the purposes of

automatically identifying and tracking tags attached to objects. Some tags requireno battery and are powered and read at short ranges via magnetic fields

(electromagnetic induction). Others use a local power source and emit radio

waves (electromagnetic radiation at radio frequencies). The tag contains

electronically stored information which may be read from up to several meters

away. Unlike abar code, the tag does not need to be within line of sight of the

reader and may be embedded in the tracked object.

RFID tags are used in many industries. An RFID tag attached to an automobile

during production can be used to track its progress through the assembly line.

Pharmaceuticals can be tracked through warehouses.Livestock and pets may have

tags injected,allowing positive identification of the animal.

Fig 2.41 Radio Frequency Identification
http://en.wikipedia.org/wiki/Electromagnetic_fieldhttp://en.wikipedia.org/wiki/Electromagnetic_inductionhttp://en.wikipedia.org/wiki/Radiohttp://en.wikipedia.org/wiki/Electromagnetic_radiationhttp://en.wikipedia.org/wiki/Bar_codehttp://en.wikipedia.org/wiki/Microchip_implant_%28animal%29http://en.wikipedia.org/wiki/Microchip_implant_%28animal%29http://en.wikipedia.org/wiki/Microchip_implant_%28animal%29http://en.wikipedia.org/wiki/Microchip_implant_%28animal%29http://en.wikipedia.org/wiki/Bar_codehttp://en.wikipedia.org/wiki/Electromagnetic_radiationhttp://en.wikipedia.org/wiki/Radiohttp://en.wikipedia.org/wiki/Electromagnetic_inductionhttp://en.wikipedia.org/wiki/Electromagnetic_field


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Radio frequency is a technology similar in theory to bar code identification. An

RFID system consists of an antenna and a transceiver, which read the radio

frequency and transfer the information to a processingdevice,and atransponder,

or tag, which is anintegrated circuit containing the RF circuitry and information

to be transmitted.

Applications:

RFID can be used in a variety of applications, such as:

Access management

Tracking of goods

Tracking of persons and animals

Toll collection andcontactless payment

Machine readable travel documents

Tracking sports memorabilia to verify authenticity

Airport baggage tracking logistics

Fig 2.42 Radio Frequency Identification
http://www.webopedia.com/TERM/B/bar_code.htmlhttp://www.webopedia.com/TERM/T/transceiver.htmlhttp://www.webopedia.com/TERM/D/device.htmlhttp://www.webopedia.com/TERM/T/transponder.htmlhttp://www.webopedia.com/TERM/I/integrated_circuit_IC.htmlhttp://en.wikipedia.org/wiki/Contactless_paymenthttp://en.wikipedia.org/wiki/Machine_readable_travel_documentshttp://en.wikipedia.org/wiki/Machine_readable_travel_documentshttp://en.wikipedia.org/wiki/Contactless_paymenthttp://www.webopedia.com/TERM/I/integrated_circuit_IC.htmlhttp://www.webopedia.com/TERM/T/transponder.htmlhttp://www.webopedia.com/TERM/D/device.htmlhttp://www.webopedia.com/TERM/T/transceiver.htmlhttp://www.webopedia.com/TERM/B/bar_code.html


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CHAPTER 3:

PROJECT DESCRIPTION

3.1 BLOCK DIAGRAM

Fig 3.1 Block Diagram


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3.2 FLOW CHART:

Fig 3.2 Flowchart showing working of Solar Tracker


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3.4 SCHEMATIC DIAGRAM:

Fig 3.3 Schematic Of Solar Tracker


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3.4SPECIFIC COMPONENTS USED IN CIRCUIT:3.4.1 RESITOR:

Resistors are the most commonly used component in electronics and their purpose

is to create specified values of current and voltage in a circuit. A device used in

electrical circuits to maintain a constant relation between current flow and

voltage. Resistors are used to step up or lower the voltage at different points in a

circuit and to transform a current signal into a voltage signal or vice versa, among

other uses. The electrical behavior of a resistor obeys Ohm's law for a constant

resistance; however, some resistors are sensitive to heat, light, or other variables.

Variable resistors, or rheostats, have a resistance that may be varied across a

certain range, usually by means of a mechanical device that alters the position of

one terminal of the resistor along a strip of resistant material. A number of

different resistors are shown:

Fig 3.4 Some Low Power Resistor Fig 3.5High-power resistors and rheostats


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The symbol for a resistor is shown in the following diagram:

Fig 3.6 Symbol of Resistor

Color Coding: Resistance value is marked on the resistor body. Most resistors

have 4 bands. The first two bands provide the numbers for the resistance and the

third band provides the number of zeros. The fourth band indicates the tolerance.

Tolerance values of 5%, 2%, and 1% are most commonly available.

Fig 3.7 Color Coding of Resistor


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3.4.2 CAPACITORS:Capacitors are components that are used to store an electrical charge and are used

in timer circuits. A capacitor may be used with a resistor to produce a timer.

Sometimes capacitors are used to smooth a current in a circuit as they can prevent

false triggering of other components such as relays. When power is supplied to a

circuit that includes a capacitor - the capacitor charges up.

When there is a potential difference (voltage) across the conductors, a static

electric field develops across the dielectric, causing positive charge to collect on

one plate and negative charge on the other plate. Energy is stored in the

electrostatic field. An ideal capacitor is characterized by a single constant value,

capacitance,measured infarads.

The capacitance is greatest when there is a narrow separation between large areas

of conductor, hence capacitor conductors are often called plates, referring to an

early means of construction. In practice, the dielectric between the plates passes a

small amount of leakage current and also has an electric field strength limit,

resulting in a breakdown voltage, while the conductors and leads introduce an

undesiredinductance andresistance.

Capacitor electron storing ability (called capacitance) is measured in Farads.

Fig 3.8 Capacitor
http://en.wikipedia.org/wiki/Potential_differencehttp://en.wikipedia.org/wiki/Electric_fieldhttp://en.wikipedia.org/wiki/Energyhttp://en.wikipedia.org/wiki/Capacitancehttp://en.wikipedia.org/wiki/Faradhttp://en.wikipedia.org/wiki/Leakage_%28electronics%29http://en.wikipedia.org/wiki/Breakdown_voltagehttp://en.wikipedia.org/wiki/Lead_%28electronics%29http://en.wikipedia.org/wiki/Equivalent_series_inductancehttp://en.wikipedia.org/wiki/Equivalent_series_resistancehttp://en.wikipedia.org/wiki/Equivalent_series_resistancehttp://en.wikipedia.org/wiki/Equivalent_series_inductancehttp://en.wikipedia.org/wiki/Lead_%28electronics%29http://en.wikipedia.org/wiki/Breakdown_voltagehttp://en.wikipedia.org/wiki/Leakage_%28electronics%29http://en.wikipedia.org/wiki/Faradhttp://en.wikipedia.org/wiki/Capacitancehttp://en.wikipedia.org/wiki/Energyhttp://en.wikipedia.org/wiki/Electric_fieldhttp://en.wikipedia.org/wiki/Potential_difference


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A basic capacitor is made up of two conductors separated by an insulator, or

dielectric. The dielectric can be made of paper, plastic, mica, ceramic, glass, a

vacuum or nearly any other nonconductive material. Some capacitors are called

electrolytics, meaning that their dielectric is made up of a thin layer of oxide

formed on a aluminum or tantalum foil conductor.

The capacitance value of any capacitor is a measure of the amount of electric

charge stored per unit of potential difference between the plates. The basic unit of

capacitance is afarad;however, this unit has been too large for general use until

the invention of the double-layer capacitor, so microfarad (F, or less correctly

uF), nanofarad (nF) andpicofarad (pF) are more commonly used.

Electrolytic Capacitor: An electrolytic capacitor is a capacitor that uses an

electrolyte (an ionic conducting liquid) as one of its plates to achieve a larger

capacitance per unit volume than other types, but with performance

disadvantages. All capacitors conduct alternating current (AC) and block direct

current (DC) and can be used, amongst other applications, to couple circuit blocks

allowing AC signals to be transferred while blocking DC power, to store energy,

and to filter signals according to their frequency.

Fig 3.9 Electrolytic Capacitor
http://en.wikipedia.org/wiki/Capacitancehttp://en.wikipedia.org/wiki/Faradhttp://en.wikipedia.org/wiki/Double-layer_capacitorhttp://en.wikipedia.org/wiki/Microfaradhttp://en.wikipedia.org/wiki/Picofaradhttp://en.wikipedia.org/wiki/Picofaradhttp://en.wikipedia.org/wiki/Microfaradhttp://en.wikipedia.org/wiki/Double-layer_capacitorhttp://en.wikipedia.org/wiki/Faradhttp://en.wikipedia.org/wiki/Capacitance


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3.4.3 TEMPERATURE SENSORS:Temperature sensors are devices used to measure the temperature of a medium.

There are 2 kinds on temperature sensors:

Contact Sensors: Contact temperature sensors measure the temperature of

the object to which the sensor is in contact by assuming or knowing that

the two (sensor and the object) are in thermal equilibrium, in other words,

there is no heat flow between them.

Noncontact Sensors: Most commercial and scientific noncontact

temperature sensors measure the thermal radiant power of the Infrared or

Optical radiation received from a known or calculated area on its surface

or volume within it.

Table 3.1 Types of Temperature Sensor
https://controls.engin.umich.edu/wiki/index.php/File:Temp.SensorTable3.jpg


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3.4.4 DC GEARED MOTOR:Geared DC motors can be defined as an extension of DC motor which already had

its insight details demystified. A geared DC Motor has a gear assembly attached

to the motor. The speed of motor is counted in terms of rotations of the shaft per

minute and is termed as RPM .The gear assembly helps in increasing the torque

and reducing the speed. Using the correct combination of gears in a gear motor,

its speed can be reduced to any desirable figure. This concept where gears reduce

the speed of the vehicle but increase its torque is known as gear reduction.

External Structure: At the first sight, the external structure of a DC geared

motor looks as a straight expansion over the simple DC ones.

Fig 3.10 External Structure of DC Geared Motor

The lateral view of the motor shows the outer protrudes of the gear head. A nut is

placed near the shaft which helps in mounting the motor to the other parts of the

assembly.


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Fig 3.11 Lateral view of DC Geared Motor

Working of the DC Geared Motor: The DC motor works over a fair range of

voltage. The higher the input voltage more is the RPM (rotations per minute) of

the motor. For example, if the motor works in the range of 6-12V, it will have the

least RPM at 6V and maximum at 12 V.

In terms of voltage, we can put the equation as:

RPM= K1 * V, where,

K1= induced voltage constant

V=voltage applied

The working of the gears can be explained by the principle of conservation of

angular momentum. The gear having smaller radius will cover more RPM than

the one with larger radius. However, the larger gear will give more torque to the

smaller gear than vice versa. The comparison of angular velocity between input

gear (the one that transfers energy) to output gear gives the gear ratio. When

multiple gears are connected together, conservation of energy is also

followed. The direction in which the other gear rotates is always the opposite of

the gear adjacent to it.


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3.4.5 LIGHT EMITTING DIODE(LED):A light emitting diode (LED) is known to be one of the best optoelectronic

devices out of the lot. The device is capable of emitting a fairly narrow bandwidth

of visible or invisible light when its internal diode junction attains a forwardelectric current or voltage. The visible lights that an LED emits are usually

orange, r

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