Michael A. Terrell wrote:
D Peter Maus wrote:
Michael A. Terrell wrote:
D Peter Maus wrote:
Actually, they are, in a way, getting in on the LED wagon. Here
in The Windy, as well as in a good number of venues I've visited
in Wisconsin, the traffic lights have been changed from
incandescent, to LED arrays. They're very harsh to look at
without the original color filters used with the incandescents
because the colors are pure, and the viewing angle is
narrow...putting the output of nearly 100 high output LED's into
a narrow beam. Small matter. Slap the filter over the LED's and
you've got a mellower color output with no diminution in
brightness. ]

They'll last. Lower maintenance costs. Total energy for the
traffic system is reduced, but not by as much as you might think.
But they depending on installation and operating parameters,
produce a hellaceous amount of RF noise. The LED arrays in my
area cast RFI shadows as far inland as my house.

They are already having to replace LED traffic lights that are
barely a year old. One of the Red LED lights near my house started
failing at six months, and continued till only about 10$ of it
still worked. Some whole strings were out, while others had LEDs
that were so dim you could barely see them. One hot summer was all
it took to start the failures. I see quite a few green LED lights
with several dead LEDs, as well.



Yeah, I asked one of the workers at the local highway department about
that. He says that QC is inconsistent between suppliers. They had
similar problems in some suburbs around Chicago, though I've never seen
it. Attributed to consequences of buying from the wrong vendors.
Locally, that kind of failure is not an issue. Two villages over...more
than a few headaches.

I asked if the issue was related to poor voltage/current regulation,
or just poor construction. The guy I talked to said he had no idea.


I used to work with someone who now works for the county technical
department. I'm going to see if I can get my hands on some bad LED
traffic light assemblies to do failure analysis.




Excellent. Post your results, if you don't mind.