View source for Talk:Biking
From Openmoko
You do not have permission to edit this page, for the following reasons:
You can view and copy the source of this page:
Return to Talk:Biking.
You do not have permission to edit this page, for the following reasons:
You can view and copy the source of this page:
Return to Talk:Biking.
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.
The FreeRunner can be put in series to the continuously running lights. There is no need for a voltage regulator. A powerful Z-diode with 4.xV parallel to the USB voltage input should be sufficient. Maybe a power LED can be used directly. In combination with a homebrown LED light only one rectifier is needed.