Re: Anyone moved to LED Lighting?

[don@xxxxxxxxxxxxxx (Don Klipstein)]

In article <lrCOm.78212$Wf2.529@xxxxxxxxxxxx>, Josepi wrote:
>As some of the articles point out LED testing may be done unfairly, is many
>cases. The manufactures show lumen output for bare elements and then add the
>reflectors, lenses and other external parts later.
>
>The ballast in not usually included in the efficiency testing, either.
>
>Are these the white phosphour screen based LEDs, you refer too?
>
>As a side note our company put in hundreds of OSRAM indicator pilot lamps on
>electrical control panels. After 10-15 years of replacing bulbs, burnout,
>sock melting, changing ballast current limiters, lenses and filters,

  Due to someone not knowing how to implement the LEDs properly, though 15
years ago efficiency of LEDs was a lot less and maybe they could not have
been implemented properly.

> we changed them all back and retrofitted them to incandescent bulbs.
>
>Certain colours, green especially, could not be dicerned, when illuminated,
>if there was any windows with sunlight entering into the buildings. If we
>put a similar green pilot lamp  with a lime green filter in it (unlit)
>beside a normal green illuminated unit, no difference could be detected.

  This problem is very easy to avoid with the green LEDs that are
available nowadays, not too hard to avoid with green LEDs that have been
available since about 2000-2001 or so.

>When we increased the drive current, the bulbs only lasted a month or so (at
>a cost of about $5 per bulb). These were very tiny LED segments with about 9
>elements in each bulb. The ballast resistor dropped the current from a
>130vdc battery bank and was a burn hazard for humans.

  Have a look at what just one modern good InGaN green LED can do with
5-10 mA now, or what one made by Nichia in 2001 can do.

> Inverter technology
>was a much better proposition but too expensive a retrofit for so many
>bulbs. They spent tens of thousands of dollars trying all of OSRAM's
>tehnologies they had availble for about 10 years and finally went back to
>incandecent bulbs with low current supplies (less than the LEDs) and the
>bulbs last about 10-15 years (or until your turn them off, after a few years
>of usage...LOL).

  Did you run controlled tests?  I have heard of testing showing that most
incandescents do not lose much life to cold starts.  They do become unable
to survive a cold start before they become unable to survive continuous
operation, but not by a lot.  The usual incandescent failure is from a hot
thin spot in the filament, prone to temperature overshoot beyond its
already-excessive temperature when a cold start is imposed upon it.  This
bad condition of an aging filament accelerates worse than exponentially,
and an aging filament that cannot survive a cold start will kick the
bucket soon no matter what.

 - Don Klipstein (don@xxxxxxxxx)

>In the last few years the pilot lamps got smarter and went to a non-filtered
>LED holder, so the area of illumination decreased and the LED elements were
>now visible. This made the LEDs visible and workable but the whole thing
>dazzled the eyes like a Christmas tree.
>
>
>"Don Klipstein" <don@xxxxxxxxxxxxxx> wrote in message
>news:slrnhglqq8.6b4.don@xxxxxxxxxxxxxxxxx
>> In article <aNBOm.39295$X01.30413@xxxxxxxxxxxx>, Josepi wrote:
>>  Cost is an obstacle, but plenty of available white LEDs are now a lot
>> more efficient than incandescents.  Efficiency like that of CFLs is now
>> the cutting edge for available warm white ones, and cool white ones
>> without high color rendering index now get as efficient as T8
>> fluorescents.
>>
>>  Osram recently put an 8 watt LED bulb on the market in Europe, with as
>> much lumen output as an 8 watt CFL.
>>
>> - Don Klipstein (don@xxxxxxxxx)
>>
>
>