"Jeff Wisnia" wrote in message
...
hobbes wrote:
Hi,

I have a Lutron dimmer that dims a 100w (4 x 25w) light fixture in a
bathroom. I noticed that one of the 25w bulbs was out and that the
dimmer does not dim any more. My question is can a bulb burning out
cause a sufficiently high current transient / short to burn out a
dimmer?

I read in this news group that bulbs blowing can be a reason that a
dimmer fails. Is this true?

best, Mike.


Yes, what occasionally happens when a bulb burns out is that a phenomena
called a "tungsten arc" occurs. The filament break develops an arc between
the broken ends which melts those ends and vaporizes some tungsten. The
arc continues, melting more tungsten and shortening the remaining filament
ends and the current increases as more of the filaments melt and the
density of the vaporized tungsten increases.

It all happens faster than you can say Jill Robinson, usually accompanied
by a bright white flash just as you "turn on the lights".

That sounds about right- those junk candle bulbs seem to go out with a bang.

aem sends....