Emergency Mobile Charger

Project Report

Created By :

Armughan Bhutta Group Members :

Muhammad Akmal Noor Tahir Raza Jilani

Abstract :In this report we are going to introduce you with unique type of cell phone charger which is Portable/Emergency Mobile Charger.

Purpose :Cell phones have become a necessity for many people throughout the world. The ability to keep in touch with family, business associates, and access to email are only a few of the reasons for the increasing importance of cell phones. Today's technically advanced cell phones are capable of not only receiving and placing phone calls, but storing data,even can be used for taking pictures .These has only power source is rechargeable batteries. Today’s smart phone can withstood maximum one day of charging. When we are on long route or out of station we couldn’t find any proper way for charging cell phone we need power backup to operate our devices. So that need lead us to make such a circuit that store charge and at the time of need we can utilizes that for charging our devices.

Components : Transformer:

We used a center-taped stepdown transformer for getting 12 volts from 220 AC.

Diode : Two types of diodes are used in this circuit for rectifying the voltage and are listed bellow :

1.1N40072. Zener 11v 0.5W

Regulator : Two types of Voltage Regulators are also used which are listed bellow:

1. LM317T2.LM7805 BJT :

A BD139 is used to measure the charged voltage of the Battery.

Resistors : There are many different values resistors are there in the circuit to manage and control the flow of current.

Battery : 12volts Ni Battery is used to store the charge for providing uninterruptable supply.

Power Cable : Power cable is used to connect circuit to AC Voltage source.

USB Port : From USB Port we take output

Data Cable : It is used to attach the Cell Phone to charge it.

Circuit Diagram:

Part 1(Battery Charger):

Part 2(Mobile charger):

Working :Circuit is basically consists of two parts 1 is Battery charger and other is mobile charger. First of all the circuit is connected to AC Voltage source through power cable and then the 220 volts AC stepdown to 12v and then this AC is passed through diodes to convert it to DC .After passing through the diodes we get pulsating DC Then there is a capacitor ahead to smoothen the pulsating DC after capacitor the voltage is not complete smoothen then we pass this to LM317T regulator which completely smoothen the 12volts DC ahead of this there is a battery to store the charge .Now the current inters the 2nd part of circuit which take 12v from battery and convert it to 3.7v and we get output from an A-TYPE USB-Port then through data cable we can charge our device.This converging takes place as, first the voltage from battery passes through a capacitor and then it passes through a regulator which take 12v input and gave us 4v output ahead of this there is again a capacitor which smoothen they any fluctuation present in the output wave form.The output is connected with USB-Port then this is connected to device which have to be charged.