SOLAR WIRELESS PHONE CHARGING

A .
CAPSTONE
PROJECT REPORT
ON
SOLAR WIRELESS PHONE CHARGING
Submitted in partial fulfillment for the award of the diploma in
Electrical Engineering
Submitted by
1. Bahurupi Santosh Suryakant (2216850112)
2. Gaikwad Sujit Bharat (2216850111)
3. Pawar Swapnil Balasaheb (2216850138)
4. Pawar Omkar Shahaji (2216850096)

Under the Guidance of

Prof. Khapekar A.R.

DEPARTMENT OF ELECTRICAL ENGINEERING

SHREE RAMCHANDRA COLLEGE OF ENGINEERING
LONIKAND , PUNE 412216
A.Y – 2024-25

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SOLAR WIRELESS PHONE CHARGING

CERTIFICATE

This is to certify that Mr. Bahurupi Santosh (2216850112), Mr.

Gaikwad Sujit (2216850111), Mr. Pawar Swapnil (2216850138),
Mr. Pawar Omkar (2216850096) from Shree Ramchandra College of
Engineering Lonikand pune. Institute has completed project of final year
having title Solar Wireless Phone Charging during the academic year
2024-2025. The project is selected & completed in a group consisting of
four students, under the guidance by project cordinator Prof. Mali. S.M. &
project guide Prof. Khapekar A.R.

Prof. Khapekar A. R. Prof. Mali. S.M. Prof. Gunaware R.P.

Project Guide Project cordinator HOD

External Examinar Prof.Dr.A.D.Desai

Principal

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ACKNOWLEDGEMENT

There are, however, several individuals that have gone well beyond
the normal call of duty and now I would like to thanks them. First of all,
I would like to thanks Mr. Mali S.M. for his invaluable guidance,
indomitable efforts, motivation and co-operation during my diploma
studies. I thank him for his incredible vision and technical mastery in field
of Control System Engineering, it is only with his guidance and
mentoring, this project was made possible. I am also very thankful to
principal, Prof. Dr. A.D. Desai and HOD Electrical Engineering, Mr.
R.P. Gunaware, and Diploma Project. Coordinator Mr. Mali S.M. for
sparing their precious time to evaluate the progress of my work. Their
suggestion have been valuable. I would also like to thank all faculty
members of Electrical Engineering Dept. for their kind help during
my academic work. I am grateful to all of the technical staff of the
department without whose help I could not have completed this project.
Thanks go out to all my friends in the Electrical Laboratory to provide
useful suggestion, companionship and created a peaceful environment.
Space does not allow me to mention each person by name, I’m
deeply grateful to everyone that has been associated with this project.

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SOLAR WIRELESS PHONE CHARGING

DECLARATION

“We hereby declare that this submission is my own work and that
the best of my knowledge and belief, it contain on material previously
published or written by another person nof material which has been
accepted for the award of any other degree or diploma of the university or
other institute for higher learning, except where due acknowledgment has
been made in the text.”

SR.NO. Name En. No. Sign

1. Bahurupi Santosh Suryakant 2216850112
2. Gaikwad Sujit Bharat 2216850111
3. Pawar Swapnil Balasaheb 2216850138
4. Pawar Omkar Shahaji 2216850096

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INDEX

Sr. Chapters Page

No. No.
1. Chapter 1 1-7
1.1 Abstract
1.2 Introduction
2. Chapter 2 8-8
2.1 Importance of this system

3. Chapter 3 9-9
3.1 Circuit Daigram

4. Chapter 4 10-11
4.1 Principle of working
4.2 Operation of system
5. Chapter 5 12-19
5.1 List of materials
5.2 Specifications of materials

6. Chapter 6 20-20
6.1 Cost of project with equipments
7. Chapter 7 21-23
7.1 Advantages
7.2 Disadvantages
7.3 Applications
8. Chapter 8 24-25
8.1 Photos of project
9. Chapter 9 26-26
9.1 Conclusion

10. Chapter 10 27-27

10.1 References

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SOLAR WIRELESS PHONE CHARGING

CHAPTER 1

1.1 ABSTRACT

Gadgets like phones, iPods, smart watches, etc. have become

an important part of our life. They all face one problem, and that is the
need to charge after regular usage. It becomes a major concern when you
are in a place where electricity is not available. One of the solutions to
these kinds of problems is to depend on the renewal energy sources.
There are different types of renewable energy sources like wind, tidal,
solar, etc. In today's project, we are going to use solar energy to charge
our mobiles. To convert solar energy into electricity, we will need solar
panels. We will see how a solar panel works, how it charges the mobiles,
and we charge mobile by wireless way or by using USB cable

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1.2 INTRODUCTION

This project presents a solar-powered phone charging system,

designed to provide a portable, efficient, and environmentally
sustainable solution for charging mobile phones. The system utilizes
a solar panel, and power converter to convert sunlight into electrical
energy. This innovative system offers a reliable and cost-effective
alternative to traditional fossil fuel-based charging methods,
promoting eco-friendly practices and reducing carbon emissions.
Ideal for outdoor activities, emergency situations, and rural or
remote areas, this project demonstrates the potential for renewable
energy solutions to address global energy challenges. Furthermore,
this project aims to contribute to the global transition towards
renewable energy sources, enhancing energy accessibility and
sustainability. The system's efficiency, durability, and affordability
make it an attractive solution for individuals, communities, and
organizations seeking to reduce their environmental footprint.

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CHAPTER 2

2.1 IMPORTANCE OF THIS PROJECT

The Solar Wireless Phone Charging Project addresses various

environmental, social, economic, technological, and global needs.
From an environmental perspective, the project helps reduce carbon
footprint by mitigating carbon emissions and conserving natural
resources for future generations. By harnessing solar energy, the
project reduces the demand for non-renewable energy sources,
contributing to a cleaner environment. Socially, the project provides
reliable and efficient energy access for charging mobile phones,
particularly in off-grid areas. This enhances connectivity and
communication, improving the quality of life for individuals and
communities. By providing a reliable means of charging mobile
phones, the project enables individuals and communities to stay
connected and access essential services. Economically, the project
reduces energy costs associated with charging mobile phones,
particularly for individuals and communities that rely on expensive
and polluting energy sources. By providing reliable and efficient
energy access, the project promotes economic development,
enabling individuals and communities to access new economic
opportunities and improve their livelihoods. From a technological
perspective, the project develops innovative energy solutions,
harnessing solar energy to charge mobile phones. This promotes the
adoption of renewable energy technologies and improves energy
efficiency, reducing energy waste and promoting the sustainable use
of energy resources. Globally, the project addresses energy poverty,
providing reliable and efficient energy access for charging mobile
phones, particularly in off-grid areas. By contributing to global
efforts to mitigate climate change, the project reduces reliance on
fossil fuels and promotes the adoption of renewable energy
technologies, ultimately contributing to a more sustainable future.

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SOLAR WIRELESS PHONE CHARGING

CHAPTER 3

3.1 CIRCUIT DAIGRAM

CHARGING
WIRELESS
SOLAR

PAD
Solar wireless
charging pad
.

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SOLAR WIRELESS PHONE CHARGING

CHAPTER 4

4.1. PRINCIPLE OF WORKING

. Solar cell are works on the principle of photovoltaic energy, a solar cell
consists of two types of semiconducting materials, p-type (positive)
and n-type (negative), which are combined to form a p-n junction.
When sunlight hits the solar cell, it excites the electrons in the p-type
material, causing them to flow through the material and create an
electrical current. The n-type material helps to collect and direct the
electrons, creating a flow of electrical current. This current is then
collected and sent through a metal conductor, generating electrical
energy.

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4.2 OPERATION OF SYSTEM

The working of the solar mobile charger circuit is simple to

understand. At first, place the whole setup in a place where get the
maximum solar rays. To get the desired output voltage from the
. circuit, adjust the potentiometer (Use a multimeter to measure the
output voltage of the circuit). Once we got the desired voltage (5V
will be sufficient to charge a cell phone), connect the micro USB to
the mobile phone. If there is proper solar radiation available for the
solar panel, the phone will get circuit will not charge our battery once
it reaches the required voltage, and our phone battery is protected
from overcharging.
Let us see how our circuit protects the battery from overcharging.
Before understanding the protection from overcharging, let us
understand a little bit about Zener diode. Zener diode is similar to that
of a normal diode, but the only difference is that when connected in
reverse bias, at certain input voltage, the Zener diode will start
conduction. The voltage at which the Zener diode conducts in reverse
bias is called reverse voltage or Zener voltage (Vz). If a Zener diode
of Vz 5V is connected in the reverse bias and applied an input voltage
higher than that of Vz, the Zener diode will start to conduct even in
reverse bias mode, but the voltage parallel to Zener diode will always
be 5V. Now, coming to the overcharge protection, If the user sets the
desired output voltage (by varying the potentiometer) to 5V and
choose a Zener diode of Vz = 5V, the circuit works fine until the
battery at the charging end is below or equal to 5V. Once the voltage
of the battery at the charging end is more than the 5V, the Zener diode
will start to conduct in the reverse bias (as the Zener voltage is 5V).
This makes the transistor BC547 to operate in forward bias mode,
which cuts off the R2 resistance from the circuit and the output
voltage from our circuit will be 1.25 volts (from the formula of
LM317, keep R2 =0). This voltage is not sufficient to charge our
battery. In this way, our circuit will not charge our battery once it
reaches the required voltage, and our battery is protected
from overcharging.
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CHAPTER 5

5.1 LIST OF MATERIAL

i) Solar panel (12v, 80mA) -1

ii) LM317 Voltage Regulator -1
iii) BC547 NPN Transister – 1
iv) Potentiometer (10K) -1
v) 1N5819 Diodes -2
vi) Resisters 100 Ohm & 150 Ohm -2
vii) 6v 1N4734A Zener Diode -1
viii) Micro USB cable -1
ix) Wireless chargerging pad -1

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SOLAR WIRELESS PHONE CHARGING

5.2 SPECIFICATION OF MATERIALS

i). Solar panel

Step1: Solar panels are made up of photovoltaic (PV) cells, which are
. made from semiconducting materials like silicon. When sunlight hits a
PV cell, the photons are absorbed by the material.
Step2: The absorbed photons energize the electrons in the PV cell,
causing them to become excited. This excitement allows the electrons
to flow freely.
Step3: Electron-hole Pair creation when an electron is excited, it
leaves behind a hole. The electron-hole pair is created, and the
electron is free to flow through the material.
Step4: Electron flow the excited electrons flow through the material,
creating an electrical current. This current is known as direct current
(DC).
Step5: The electrons are collected at the surface of the PV cell and
sent through a network of metal wires.
Step6: The collected electrons generate DC power,
each solar cell has a voltage of 0.33v to 0.36v. Total voltage of solar
panel is 12v & 80mA

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ii). LM317 Voltage Regulator

LM317 is a variable voltage regulator. By using LM317, we can vary

the voltage up to 37V with a max current of 1.5A. To get the variable
output voltage, the below circuit is used.

The output voltage can be calculated by using the below formula:

Vout = 1.25(1 + (R2/R1))
Now, by varying the value of the resistor R2, you can vary the output
voltage.
Note: Even though the output voltage is dependent on the external
resistors connected to the LM317, the input voltage should be greater
(minimum of 3V) than the desired output voltage.

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iii). BC547 NPN Transister

BC547 is a bipolar junction transistor (BJT).

• It is kind of an NPN transistor.
• It has three terminals: Emitter, Collector and Base.
.

 Electrical Characteristics:
1. Collector-Base Voltage (Vcb): 30V.
2. Collector-Emitter Voltage (Vce): 30V.
3. Emitter-Base Voltage (Veb): 5V.
4. Collector Current (Ic): 1A.
5. Base Current (Ib): 50mA.
6. DC Current Gain (hfe): 100-300.

 Switching Characteristics:
1. Transition Frequency (ft): 100MHz.
2. Storage Time (ts): 100ns.
3. Fall Time (tf): 50ns.
4. Rise Time (tr): 50ns.

 Thermal Characteristics:
1. Junction Temperature (Tj): 150°C.
2. Storage Temperature (Tstg): -55°C to 150°C.
3. Thermal Resistance (Rth): 62.5°C/W.

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SOLAR WIRELESS PHONE CHARGING

iv) 1N5819 Diode

The 1N5819 is a type of Schottky diode, which is a

semiconductor device that allows current to flow in one direction
while blocking it in the other.

 Characteristics:
1. Voltage Rating: 30V
2. Current Rating: 1A
3. Reverse Leakage Current: 0.1mA
4. Forward Voltage Drop: 0.45V
5. Switching Speed: Fast switching times (typically <100ns)

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SOLAR WIRELESS PHONE CHARGING

v) Zener Diode

Zener diode is similar to that of a normal diode, but the only difference
is that when connected in reverse bias, at certain input voltage, the
Zener diode will start conduction. The voltage at which the Zener
diode conducts in reverse bias is called reverse voltage or Zener
voltage (Vz). If a Zener diode of Vz 5V is connected in the reverse
bias and applied an input voltage higher than that of Vz, the Zener
diode will start to conduct even in reverse bias mode, but the voltage
parallel to Zener diode will always be 5V. Now, coming to the
overcharge protection, If the user sets the desired output voltage (by
varying the potentiometer) to 5V and choose a Zener diode of Vz =
5V, the circuit works fine until the battery at the charging end is below
or equal to 5V.

Once the voltage of the battery at the charging end is more than the
5V, the Zener diode will start to conduct in the reverse bias (as the
Zener voltage is 5V). This makes the transistor BC547 to operate in
forward bias mode, which cuts off the R2 resistance from the circuit
and the output voltage from our circuit will be 1.25 volts (from the
formula of LM317, keep R2 =0). This voltage is not sufficient to
charge our battery. In this way, our circuit will not charge our battery
once it reaches the required voltage, and our battery is protected
from overcharging.

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SOLAR WIRELESS PHONE CHARGING

vi) Micro USB cable

The cable contains a micro USB connector, which is used to connect

to the mobile phone and 4 wires on the other end of the cable. The
micro USB cable consists of 4 pins. Two for transferring power and
another two for transferring data. The pinout of the micro USB cable
needed for transferring the power

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SOLAR WIRELESS PHONE CHARGING

vii) Wireless Charging Pad

Wireless charging pads work through electromagnetic induction,

where a coil in the charging pad generates a magnetic field when an
electric current flows through it. When a device, such as a
smartphone, is placed on the charging pad, the magnetic field
induces an electric current in the device's receiver coil. This current
is then rectified and regulated to match the device's charging
requirements, and is used to charge the device's battery. The
process happens automatically, and the device starts charging as
soon as it's placed on the charging pad.

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CHAPTER 6

6.1 COST OF PROJECT WITH EQUIPMENT COST

Sr. No. Equipment specification Qty. Cost (Rs)

1. Solar panel (12v,0.80mA) 1 1220/-

2. Electronic circuit components 8 165/-

 Resister (100ohm & 150ohm )-2
 Diodes 1N5819 -2
 Zenor diodes (6v 1N4734A) -1
 Transister BC547 -1
 Potentiometer (10k) -1
 voltage regulator (LM3171) -1
3. Micro USB cable (type V8 & type C) 2 190/-

4. Wireless charging pad (15w) 1 810/-

5. Other cost (glue,screws,frame,etc.) -- 355/-

Total cost = 2790/- Rs

 Total cost of project is - Rs 2790/-

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SOLAR WIRELESS PHONE CHARGING

CHAPTER 7

7.1 ADVANTAGES

a). Renewable Energy Source:

Solar power is a renewable energy source that uses sunlight as a fuel,
reducing dependence on fossil fuels.

b). Zero Emissions:

Solar power charging produces no emissions, making it an
environmentally friendly option.

c). Low Operating Costs:

Once installed, solar panels require minimal maintenance and have no
fuel costs.

d). Energy Independence:

Solar power charging allows users to generate their own energy,
reducing reliance on the grid.

e). Government Incentives:

Many governments offer incentives, such as tax credits or rebates, for
installing solar panels.

f). Durable:
Solar panels can last for up to 30 years or more, making them a long-
term investment.

g). No Maintenance:
Solar panels are require no maintenance, as they have no moving parts.

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7.2. DISADVANTAGES

a). Dependent on Sunlight.

The biggest drawback of solar-powered chargers is their dependence
on sunlight. Performance can be significantly affected by weather
conditions, time of day, and the angle of the sun. In cloudy or shaded
environments, these chargers may not be as effective.

b). Limited Power Output.

Solar panels have limited power output, which can make it difficult
to charge high-power devices like smartphones quickly.

c) Space Requirement.
Solar panels require a significant amount of space to generate
enough power to charge a phone.

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SOLAR WIRELESS PHONE CHARGING

7.3 APPLICATIONS

a) Outdoor Areas
Solar wireless chargers are perfect for outdoor enthusiasts, such as
hikers, campers,

b) Remote Areas
Solar wireless chargers can be used in rural or remote areas where
access to electricity is limited, providing a sustainable and reliable
source of power.

c) Tourism Industry
Solar-powered phone charging can be used in the tourism industry to
provide phone charging services to tourists.

d) Emergency Situations
Solar-powered phone charging can be a lifesaver in emergency
situations like natural disasters or power outages.

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Chapter 8

8.1 PHOTOS OF PROJECT

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SOLAR WIRELESS PHONE CHARGING

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SOLAR WIRELESS PHONE CHARGING

CHAPTER 9

9.1 CONCLUSION

The solar power phone charging project was a successful endeavor

that demonstrated the feasibility of using solar energy to charge mobile
phones. The project showcased the potential of renewable energy
sources to provide sustainable and environmentally friendly solutions
for everyday needs.

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CHAPTER 10

10.1 REFERENCES

1. "Solar Powered Phone Charging System" by S. S. Rao et al.,

published in the International Journal of Advanced Research in
Electrical, Electronics and Instrumentation Engineering (2017)
2. "Design and Development of Solar Powered Mobile Phone
Charger" by A. K. Singh et al., published in the Journal of Solar
Energy Engineering (2018)
3. "Solar Powered Phone Charging System with Maximum Power
Point Tracking" by M. A. El-Sayed et al., published in the Journal
of Renewable and Sustainable Energy (2019)
4. Solar Powered Phone Charging: A Review" by Electronics Hub
(2020)
5. "Solar Power for Beginners: A Guide to Charging Your Phone and
Other Devices" by U. S. Department of Energy (2019)
6. Solar Powered Phone Charging System with Battery Backup" by S.
K. Singh et al., US Patent 10,442,111 (2020)

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Thank You….

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