Joe Analssandrini wrote:

Dear Bruce (any everyone else here),

Within the last two months General Electric and Konica Minolta have
signed a strategic alliance agreement to develop and commercialize
Organic-Light-Emitting-Diode (OLED) devices for home and industrial
lighting applications. It is their intent to have these devices on the
market within three years! OLEDs can be fabricated in sheet form which
is flexible (imagine THAT!), thin, and lightweight. This form of
lighting may eventually be incorporated into walls or ceilings,
eliminating the need for separate light fixtures (table lamps, and so
forth). Color temperature can be anything desired! They've got it NOW;
they must develop inexpensive manufacturing techniques for it to
become commercially viable.

Obviously those two companies are quite confident in their ability to
do so.

And of course the OLED's energy usage is but a small fraction of what
is used in todays bulbs.

Best,

Joe


Last I knew, a problem with OLEDs was a limited lifespan compared with
regular LEDs.

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.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

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.

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.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

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.

D Peter Maus wrote:

Michael A. Terrell wrote:

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.


No problem. I'm mainly interested in the power supply, since strings
of about 12 go out at a time. I want to find out if its a crappy SMPS,
ar maybe a couple to reduce the chance of catastrophic failures. Now,
all I have to do is get my hands on some samples. I may try contacting
Florida DOT. If they are rebuildable, I am looking for a few projects to
create part time jobs for local Disabled Veterans. I'll bet that they
can replace bad capacitors and LEDS after they are troubleshot.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

Michael A. Terrell wrote:

D Peter Maus wrote:

Michael A. Terrell wrote:

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.

No problem. I'm mainly interested in the power supply, since strings
of about 12 go out at a time. I want to find out if its a crappy SMPS,
ar maybe a couple to reduce the chance of catastrophic failures. Now,
all I have to do is get my hands on some samples. I may try contacting
Florida DOT. If they are rebuildable, I am looking for a few projects to
create part time jobs for local Disabled Veterans. I'll bet that they
can replace bad capacitors and LEDS after they are troubleshot.

The first generation of LED traffic lights in my area started to fail in
about a year. It looked like there were random failures of each LED
element. I didn't notice if they were part of a string. The newer LED
traffic lights are lasting much longer. I've also wondered why the new
sodium street lights seem to have a shorter life than the mercury vapor
ones they replaced. The opposite is supposed to be true. The sodium
lights can be a serious source of RFI when they start to cycle on and
off at the end of their life. Some people think they have the ability to
make the sodium lights go out when they're near them. It's really just a
coincidence but you can't convince them of that. If you do a Google
search for 'street lights turning off' you'll find all kinds of
testimonials, including paranormal explanations.

I don't know if the street lights on the street I live on are sodium or
mercury lights.Whatever they are,they last a very long time.The traffic
lights around here seem to be working ok.
cuhulin

HFguy wrote:

The first generation of LED traffic lights in my area started to fail in
about a year. It looked like there were random failures of each LED
element. I didn't notice if they were part of a string. The newer LED
traffic lights are lasting much longer. I've also wondered why the new
sodium street lights seem to have a shorter life than the mercury vapor
ones they replaced. The opposite is supposed to be true. The sodium
lights can be a serious source of RFI when they start to cycle on and
off at the end of their life. Some people think they have the ability to
make the sodium lights go out when they're near them. It's really just a
coincidence but you can't convince them of that. If you do a Google
search for 'street lights turning off' you'll find all kinds of
testimonials, including paranormal explanations.


One that was replaced last week already has a dead red LED. I saw it
this morning on the way to the Memorial Day ceremony at our Veteran's
Park.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

Go ask Jackson,Mississippi (I live here) what kind of traffic lights
they use.
cuhulin