Originally Posted by
BigAura
My back-of-napkin calculations:
- device rated 6v, 1.5 watts at 15 kph
- charge smart phone = 10 watt hours
- 7 hours of riding should do it
- reality???
6v at only 1.5 watts is not USB power. Its only 250mAh , USB minimum is 500mAh at 5 volts. The 6v to 5v drop gains a little overhead but the ac to dc loses some.
The sinewave ( any conversion process) is not going to be 100% efficient so you will lose some there.
SON28's and other dynos that meet the German standard put out 3 watts and that's barely enough. I use a pretty efficient converter and can barely squeak out 500 mAh with a gen putting out twice as much.
Not all devices will accept a less than mimimum charge current (Apples especially) but I would test your device to see if it will accept a lower charge current first, and see if 1.5 watts is within the input threshold of the sinewave .
EDIT!!!
From the sinewave site
" Will the Revolution work with my dynamo?
Yes. The Revolution can be used with any hub, bottle or spoke dynamos.
Any standard 6V/3W dynamo will generate enough power for the Revolution to charge your device. The less-common 12V/6W dynamo can be used as well.