[Stoves] Music box guts as a spring powered fan

[andrew]

On Monday 19 February 2007 21:00, drew wrote:

> 1.    After examining and dissembling a music box I noted that the
> spring mechanism is regulated by using a small, quite high speed
> fan.


Yes we discussed this some while back when looking at the clockwork 
fan idea. This works as a governor as the power required for a given 
swept area is a cube of the air velocity, so a small change in shaft 
speed relates to a large change in power required about a critical 
air velocity.

AJH