Talk:Biking
From Openmoko
Crank up the Charge
The datasheet of the PCF50633 says Vusb=4V. What will be the input current when charging with 500mA? Let's assume not more than 500mA. So the power requirements are 2W. OK. You will loose some power in the rectifier. Maybe there's no additional voltage regulator needed.
If you want to reduce the power requirement even more, you could replace the battery by something robust, lets say a plumbium battery, and feed the regulated dynamo voltage directly the battery voltage pin. There 2.8V seem to be sufficient.