Re: ATM slowing a fan

["Bill T." <twentiethwave@hotmail.com>]

Brushless DC fans can be slowed very efficiently by simply using a battery
voltage lower than the fan's rated value.  Most such fans will operate down
to 1/2 the rated voltage, producing perhaps 1/3 the rated airflow at that
voltage.

Looking through some spec sheets, I see that almost all the 12 volt
brushless fans listed are rated for 7 to 14 volts.

I use a pair of 80mm x 15mm Panasonic "Panaflo" fans to blow accross the
face of a 20" mirror.  They produce a nice steady, quiet flow of air running
off 4 "D" cells, right around 6 volts.  Panasonic part # FBA08T12L, Digikey
stock # P9732-ND, $12.50. I like these fans because they use lots of blades
running at low RPM, which is a much quieter scheme than 3 or 4 blades
running at higher RPM's.

Bill T.