This document presents a BE minor project on a solar charging coin based mobile charging system. The system uses a solar panel to charge a battery, which then powers a coin operated mobile phone charger. It has two main parts - a solar tracking system to keep the solar panel perpendicular to the sun, and a coin paid mobile charger. Users insert coins to charge their phones for a set period of time. It is designed to provide mobile charging in public places without grid power.

1. BE Minor Project on
Solar Charging Coin Based
Mobile Charging System
PRESENTED BY:
ABINASH BARAL(BEX/071/402)
ARCHANA MALLICK(BEX/071/408)
BIBEK REGMI (BEX/071/410)
NABIN SUBEDI (BEX/071/422)

2. INTRODUCTION
 IN THIS PROJECT, WE PROVIDE A UNIQUE SERVICE OF COIN PAID
MOBILE CHARGING SYSTEM USING SOLAR PANEL
• MOBILE PHONES HAVE BECOME AN INDISPENSIBLE PART OF A
BUSINESS/PERSONAL COMMUNICATION
 WE MIGHT RUN OUT CHARGE AT ANY INSTANCE AND FAIL TO
ATTEND IMPORTANT CALLS, SEND/RECEIVE TEXTS/MAILS OR
COMPLETE OTHER TASKS IN OUR PHONES WHILE WE ARE
TRAVELLING
 THIS IS LIKE A VENDING MACHINE FOR BATTERY CHARGING WHERE,
A USER HAS TO PLUG IN A PHONE IN ONE OF THE ADAPTERS AND
INSERT AN AUTHORISED COIN FOR CHARGINGAT A CONSTANT
CURRENT FOR A DEFINITE PERIOD OF TIME
 THIS COMPACT AND LIGHTWEIGHT PRODUCT IS DESIGNED TO CATER
FOR THE UNAVAILABILITY OF POWER GRID AT A PUBLIC PLACE

3. OBJECTIVES
SPECIFIC
• To design a Solar Tracking Coin Based Mobile Charging System
GENERAL
• To provide instant charging in the public places and to cater for the
unavailability of grid power.
• To maintain perpendicular light incidence on solar panel.

4. LITERATURE REVIEW
• M.S. Vandarajan and et al in 2012 designed a coin based mobile
battery charger providing a unique service to the rural public where
grid power is not available for partial/full daytime and a source of
revenue for site providers.
• Aparna D. Pawar in 2015 designed a project where mobile charging
was started when it was inserted to the charging slot.
• S.B. Sridevi and et al in 2013 designed a Coin based mobile charger
using solar tracking system in which the mechanical movement of the
solar was controlled through the stepper motor.
• Ekta Gupta and et al in 2016 deigned a Coin Based Solar Mobile
Charger where comparator IC1502 was used which compared the
results coming from LDR1 and LDR2.

5. HOW IT WORKS?
METHODOLOGY
THE PROJECT IS DIVIDED INTO TWO STAGES:
1. SOLAR TRACKING SYSTEM
2. COIN PAID MOBILE CHARGER

6. SOLAR TRACKING DEVICE
THE MECHANICAL MOVEMENT OF THE SOLAR PANEL IS CONTROLLED
BY THE STEPPER MOTOR ACCORDING TO THE SUN INTENSITY
DETECTED BY THE LDR
FIGURE: SOLAR PANEL FIGURE: LDR

7. COIN PAID MOBILE CHARGER
• THE MOBILE BATTERY CHARGER STARTS CHARGING A MOBILE
CONNECTED TO IT WHEN AN AUTHORISED COIN IS INSERTED AT THE
COIN INSERTION SLOT
• A SAMPLE COIN IS PLACED IN THE COIN SENSOR AND THE INSERTED
COIN IS ACCEPTED OR REJECTED ON THE BASIS OF THE SAMPLE COIN
FIGURE: COIN SENSOR
• A LCD DISPLAY SHOWS CHARGING STATUS AND OTHER
INFORMATION TO THE USER
• THE OUTPUT HAS DIFFERENT TEMINALS FOR CONNECTING
DIFFERENT MOBILES

8. BLOCK DIAGRAM
LDR
LDR
LCD Display
Motor Driver
Motor
Solar panel
Battery
Coin Sensor
Relay
Mobile charger
ARDUIN
O
MEGA
2560

9. FLOWCHART
Start
coin
sensing
Refund
Box
Lever
switch
open
Collectio
n box
Charging on
Timer start
Increment
counter
Charging
complete
End

10. APPLICATIONS
• It is very useful to public for using coins to recharge their phones
anytime at any place
• This prototype can be copied and further expanded for various
industrial and commercial applications
• It can be used as a solar power bank
• It can be used in rural areas where there is no grid power