[Stoves] Hand Crank Dynamo for Fanned Stove?

[Steve Taylor]

Crispin Pemberton-Pigott wrote:
> Actually...if it is working properly it will give you 4 watts.  A watt is 1
> volt-amp-second.  If you have 0.3 x 12 = 4 volt-amp-seconds then feeding it
> back at 6 volts (by chopping the 12 volt supply) will extend the time power
> can flow and you should still get just about 4 watts total, not only 2, at
> the lower voltage.  An old fashioned resistor would indeed cut the total
> power by the voltage drop.  That is the advantage of the PWM.
>   
You get 4 watt/hours still, or whatever, but you have 2W for twice as long.

Steve