This project is inspired by the simple usb charger, Minty Boost. It helps you to re-charge your mp3 player, camera, cell phone, and just about any other gadget you can plug into a USB port with faster rate than minty boost. Instead using LT1302 chip with limited to 600mA, it uses LM2700 from National which can push up to 3.6A. This will enable your gadget to draw up to there maximum of 1A which will enable a faster recharge.
In the circuit, LM2700 is configured to push up to 2.3 Ampere. This is due to the switching duty cycle of the chip. Charging more quickly will drain and reduce the life span of AA batteries so lithium batteries are the ideal source for this board. The board will take any voltage source between 2.2V to 4.5V and will output 5V. Download: Charger Circuit.