PORTABLE MOBILE CHARGER

COMPONENTS NEEDED:

1)LM 7805 (5V voltage regulator IC).2)100 K resistors (1/4 watt 2 nos.).3)1 K resistor (1/4 watt).4)100 uF capacitor (16V or more).5)Green LED (3mm)6)Soldering iron and solder wire.7)Switch (SPST).8)USB type A female jack.9)PCB.10)Connecting wire.11)9V battery.12)PCB Terminal.

RESISTORS:

1 K

100 K

CAPACITOR

100 uF

LED

LM 7805 IC (5V voltage regulator)

1)LM 7805 is a linear voltage regulator IC.2)It can regulate a voltage to 5V DC with an

input voltage ranging from 6V to 37V approx.

3)It gives a constant current of 1A as output.

4)It is a very stable IC and is perfect for a portable charger.

LM 7805 PINOUT:

USB charging is currently the most universal method of charging an electronic device. This workshop details the process of construction of a cheap and simple portable USB charger which can be used to charge cell phones, mp3 players, cameras, etc and almost any device.

USB normally contains 4 lines – Vcc(+5V), Data-(D-), Data+(D+) and Gnd(Ground) . The Vcc and the Gnd line are used to power a device and the D- and D+ line are used to transfer data between the host and the device.

INTRODUCTION

The USB is expected to maintain 5V within a range of ± 0.5V and provide current of 100mA, unless requested for more current. To build a USB charger all you need to do is build a circuit that outputs current within the USB specification.

A cell phone could only charge if the current is 1A approx. and the voltage is 5V . Therefore the data pins on the USB are connected with 100K resistors to the 5V supply. This tells the device that the charger is connected and the device charges normally otherwise the device charges slowly.

ABOUT USB CHARGING

USB PINOUT:

CIRCUIT DIAGRAM

THE END