Most of the mobile phones these days can be charged from a USB port with an output of 5 v DC. now u can charge your mobile phones anytime anywhere using this simple portable usb charger.
Step 1: Components Needed
The components we will use are:
One - LM7805
Two - 1μf Capacitor
One - 5 Ω 3 Watt Resistor
Step 2: The Circuit Diagram
The circuit is very simple and can be soldered very quickly on a small general purpose PCB. The components from left to right are, 7805 , 5.4 ohm resistor and two 1uf capacitors.
I have sketched the layout along with the 7805's pin configuration. It is a fairly simple and straight forward circuit. The positive input is connected to both the pin one of the 7805 and the positive of the first capacitor . The pin three is connected to the positive of the capacitor and one end of the resistor, this forms the positive 5 v output. This completes our positive side. For the negative we connect all the negatives together - the negative in, negative out, negative of the first capacitor, negative of the second capacitor and pin 2 of the 7805.
The output can be taken as a wired output or a USB port can be directly mounted on to the PCB. Here you see the completed board. I have drilled two holes to secure the port later. The red and the black wires are the input wires.