On Thu, 18 Oct 2012 18:24:55 -0500, Michael Dobony
wrote:

On Thu, 18 Oct 2012 11:35:01 -0400, Twayne wrote:

In ,
Michael Dobony typed:
I just replaced 4 light bulbs a little over 2 weeks ago,
not cheap dollar store ones, but Sylvanias. All four went
out already. I replaced 2 of them last night and 1 was
burned out only 2 hours later! I checked the voltage and
it is 117. The contacts are clean and bright. Any ideas
what might be going on?

Mike D.

Vibrations, movement of the sockets, theft, Sylvania makes a lot of trash
same as all the others. My bet's on vibrations from people's feet or
machinery running or a bad connection somehow. .

no machinery. as mentioned, bad connection would lower voltage and make the
bulbs last longer. Other bulbs in same box are good.
No, bad connection will cause the fillament to fail early due to
flickering (which you may not even see) Any induction in the circuit
causes high voltage but the induction in the coiled tungsten filament
is negligible so high voltage is not the explanation (or at least not
the major influence) Flicker causes higher peak current draw, and
magnetic vibration in the coiled filament.