>  ... I remember
> playing with a variable transformer and a car headlight back in 
> grade school
> to see what happened when I lowered the voltage and at what point I 
> could
> just see the fillament glowing in a dark room.  If I remember right, 
> that
> was around 2/3 to 1/2 the rated voltage.

More like about 5% to 10% - see my rough results in another recent 
post.
A 1v 5W bulb had a barely visible filament glow at 1V. Current was 
still an appreciable %age of full value but power, being VI product, 
was well down.


        Russell

 

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist