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Re: Anyone moved to LED Lighting?



In article <MYSOm.49165$Zu5.42027@xxxxxxxxxxxx>, Josepi wrote:

>The incandescents lasted forever (well at least 4-10 years) until they were
>turned off.
>
>I believe I have the supplier mixed up. It wasn't OSRAM but another supplier
>with similiar type name???. OMRON or something..Been awhile now. These lED
>indicators were all crap and we tried many different styles and many
>different current levels. When run at their rated current (I think about
>20mA) they all went up in smoke after a few years, anyway. The main (130vdc)
>ballast resistors were mounted elsewhere so they weren't a problem. The
>problem, as I saw it were they were designed as a 24v bulb with 24vdc worth
>of ballast in a miniature bulb....that's a no..no and did them in from
>localized heat. Finally, after about 15 years of experimenting with them and
>different breeds, the Engineering department decided to ignore the
>manufacturer's advice, went back to incandescents and replace the bulbs
>every few years when the device was de-enrgized, basically.
>
>As  I stated, the LED units are back without any diffusion. LEDs just don't
>put out enough light to make them look like incandescents with diffusion and
>still be visible with bright lighting. The red and yellow ones were never a
>problem, only the green, other than being short lived.

  My experience of red, yellow and green LEDs at 20 mA, for ones
characterized at 20 mA:

  Red - my champion experience here so far is around 1.8 lumens at 20 mA.
They appear to me to achieve about .8 lumen at 10 mA.  (Nichia NSPR510CS)

  Yellow - I got about .6-.7 lumen at 20 mA several years ago, likely now
at least a little better.  My experiece is generally 60% of red - so I
expect Osram to have something delivering around a lumen at 20 mA
nowadays.

  Green - my champion experience so far here is 3.7-4.4 lumens at 20 mA,
more than half of this at 10 mA, averaging .94 lumen at 3 mA and around
.58 lumen at 1.7 mA, at which their efficiency is close to peak and much
improved over that at 20 mA.  Part number - Nichia NSPG520AS.

http://members.misty.com/don/led.html

 - Don Klipstein (don@xxxxxxxxx)

>"Don Klipstein" <don@xxxxxxxxxxxxxx> wrote in message
>news:slrnhgmgss.30.don@xxxxxxxxxxxxxxxxx
>> 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.
>
>
>


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