26-09-2016, 03:50 PM
1456221642-CoinBasedUniversalMobileBatteryChargerCopy.pdf (Size: 505.92 KB / Downloads: 10)
Abstract
In this paper, a novel type of coin based cell phone charger
has been designed. A new type of charger is designed for
public people utilities. This type of charger will be very useful
for the public people; many times the battery becomes flat in
the middle of the conversation in particularly at inconvenient
times when access to a standard charger isn’t possible. The
main advantage of this charger is, power supply for the
charger is determined from solar power and current supply.
The coin based cell phone charger is worked according to the
coding written in the 89c51 microcontroller IC. When we put
a coin, the coin detector detects the coin and the input is given
to the controller .The controller reads the program. At the
same time the supply is given to the charger for a particular
time period. The time period depends on the coding written in
the controller. A multi pin charger is connected through the
controller. By using the multi pin charger we may also use
more than one mobile for charging. MOSFET acts as the
switch in the circuit. This circuit can be placed in public
places such as Bus stands, Railway stations, Hospitals, etc...
Introduction
In many developing countries the current supply is not
available for several hours on daily basis especially in semi
urban and rural areas were the cell phones are the essential
communication device [1]. In the event of unpredictable
current supply and availability of abundant solar power, this
paper is designed with coin detecting mechanism,
microcontroller, real time clock, driver circuit with MOSFET,
charging circuit, inverter, cycloconverter and different phone
socket. This coin based charger is similar like a VENDING
MACHINE for charging the cell phone, the user has to plug
the phone into one of the adapters and insert the coin for the charging at constant current for a definite time period. Coin
detecting mechanism is used to detect the coin. When the user
inserts the coin, this will detect the coin and send a
corresponding signal to the signal conditioning unit in which
the incoming signal is converted into square pulse and then
given to microcontroller. The microcontroller used is Atmel,
which is a type of reprogrammable microcontroller. The
microcontroller is already programmed when the user inserts
the coin, in the coin detecting mechanism detects the coin, and
it generates the pulse to the microcontroller through signal
conditioning unit. The microcontroller activates the driver
circuit for particular time period as per coin inserted in the
machine. Driver circuit consists of transistor, it just acts as
switch to turn ON, turn OFF MOSFET. The MOSFET output
is directly connected to charging circuit. The different cell
phone charging socket is connected in the charging circuit.
Such as Nokia, Motorola, Samsung, LG, Sony, Apple, Tab,
Etc. By using this paper we can charge the cell phone as per
coin inserted in the machine. Solar chargers convert light
energy into DC current for a range of voltage that can be used
for charging the batteries [3]. In this design of coin based
charger a fixed solar panel of size 635x550x38mm, 37WP is
used to charge the battery up to 2.0amp in bright sun light.
1.1 BASIC ASSUMPTIONS
The design of coin based cell phone battery charger is based
on the following assumptions:
Maximum solar energy is used for charging lead acid
battery (mobile battery).
The charging current is up to 4.5AH @ 6vDC.
A single solar panel of size 635x550x38mm, 37WP
capable of supplying up to 2.0 amps is used.
10 different types of mobile are provided to charge
the cell phones.
1. OPERATION
1.1 INPUT STAGE
The mobile battery charger starts charging a mobile connected
to it, when a coin is inserted at the coin insertion slot at the
input stage. The type of coin and the size will be displayed at
the LCD display for the user, so as to ensure correct coin
insertion. Any other coin, if inserted in the slot will be
returned to refund box. A mechanical slot is attached with
electrical triggering in coin insertion slot, if the correct coin is
inserted, it sends a pulse to the control unit authorizing the
start of charging the mobile battery connected to the device.
Then the coin insertion slot accepts the coin into the battery
charging unit and start charging the mobile battery for a
specific period controlled by the software of the
microcontroller [1].
2.2 Controller
This section acts according to the input signal received from
mechanical detection. Coin accepted or rejected is based on
the diameter of the coin. This invokes microcontroller along
with LCD interface displays the selection of mobile option if
particular mobile is selected for charging the corresponding
routine is activated and charge the mobile for a particular
duration of time .When the routine completes, it indicates
charge complete message through LCD display. Similarly the
same procedure is followed for charging more than four
different mobiles simultaneously [1].
2.3 Output and Display
The LCD displays all the information to the user as and when
required. When the mobile battery is connected, it displays
“Insert Coin”. While charging it displays “Charging” and at
the end of charging cycle it displays “Charge completed”. For
charging continuously the coin has to be inserted when the
display shows “Charge Completed”. The output has 10
terminals for connecting different types of mobile batteries
and 7 of them are internally connected for charging mobile
batteries of different make as shown in Table 1
RESULT
In this paper a novel method of charging mobile
batteries of different manufacturer using solar power has been
designed for rural and remote areas where the current supply
is not at all available all the time. This paper is very useful in
today’s life. Because now days the necessity of
communication is very important, so every person having cell
phone but every time we cannot carry charger with us. When
we are going for long travel we may forget to carry cell phone
charger. This paper is used to help the people by coin based
charger.