"John Larkin" wrote in message
...
On Wed, 12 Dec 2012 05:32:08 -0800, "William Sommerwerck"
wrote:

Even a slight drop in voltage causes a big increase in life. For
example,
a 5% reduction almost doubles the lamp's life (1.85 times). At a 10%
reduction, the lamp lasts 3.5 times as long.

I guess the question becomes: is there some voltage a bit below normal,
where the halogen cycle doesn't work and lamp life actually degrades?
I'm guessing no.

I'm guessing yes. A friend had halogen lamps on a dimmer, which
he dimmed only slightly -- and they burned out pretty quickly.
The halogen cycle requires a very high temperature. Ergo...

If there's almost no filament evaporation, who cares if the halogen
cycle isn't working? It's not needed. And it will work if full line
voltage
is applied occasionally.

Does anyone ACTUALLY READ WHAT IS POSTED? And THINK about it? Why is it
necessary to explain something in excruciating detail over and over and over
again?