[Stoves] Variable Speed Stove Fan

[steve]

> Can you gis us a list and circuit?  I would really like to
> try it out on a  couple of sizes of fan.

Sure. 
Two questions: 
What wattage fan.
What typical supply volts.

...and do you want to run to 0 speed and 100% speed, or will
5 and 95% be OK.
Are you terribly concerned about power efficiency ?

Ultimately, with clever engineering, we might make a 1V
supply run a 12V fan at full speed, using the waste heat
from the stove, but I am still looking at the maths. 

Steve