On Thu, 11 Oct 2012 03:13:01 -0400, "Michael A. Terrell"
wrote:

Jeff Liebermann wrote:

On Mon, 8 Oct 2012 06:27:05 -0700 (PDT), George Herold
wrote:

Hi SEB. Well I sent an email to Don klipstein on this topic. And
have permission to copy his reply.
from Don K. below

2: In incandescent traffic signals, the bulbs for yellow last
longer than for red and green. So even after being switched on
and off about a million times, on-time is still a significant
factor in life expectancy.

That means for my proposed test comparing a 50% duty cycle flashing
light bulb, with one that is on continuously, the continuous light
bulb will burn out first. That's the opposite of what I saw with the
theater marquee bulbs. Now, I'm really tempted to run the experiment.

Was there any vibration in that theater marquee?

Nope unless you count the movie audio pumped in from the theater
section as vibration.

The lobby and foyer lights were probably on a different circuit from
the marquee lights, which may have had different voltages, glitches,
surges, etc. I suspect that there were also some switching
transcients on the marquee side. That was 45 years ago, and I didn't
think to measure any of that. I just kept replacing light bulbs.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558