How to Build a 9v Battery Powered USB Charger

http://www.anythingbutipod.com/archives/2009/10/how-to-build-a-battery-powered-usb-charger.php

The concept is simple; USB power is 5V. To have a charger that produces exactly 5V you need a voltage regulator. Such a regulator is the 7805 model you can get at Radio Shack for $1.59. This will take a voltage between 7.5V and 20V (according to Google research) and turn it into a steady 5V. Turn this into a charger, and there you go.
Tags: usb, diy, electronics, charger, battery, hacks, iphone, hardware, projects, howto Saved by: admin