LED brightness?

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vidarf
Posts: 504
Joined: Fri May 12, 2006 11:37 am
Location: Narvik, Norway
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LED brightness?

Post by vidarf »

Hi gents!

How bright are your LED's for the annunciators (microcandelas)?

If this topic has been covered in the past, please let me know! The search didn't help...

RocketRod
Posts: 293
Joined: Thu Jun 02, 2005 10:06 pm
Location: Colorado Springs, CO

Post by RocketRod »

Mine are bright. Just about right I think, using 2 LED's in each. Although my interface (non FDS) software allows me to set brightness. Can't discuss any more, not fair.
Rodney

737NG Pit Builder
Some Assembly Required

vidarf
Posts: 504
Joined: Fri May 12, 2006 11:37 am
Location: Narvik, Norway
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Post by vidarf »

Okay, but do you know HOW bright in microcandelas? There are LED's that are 2500 mCd, and there are 70.000 mCd ones.

Just want to know what to "shoot" for. :) I don't want to feel like I'm flying into a supernova each time a annunciator lights up...

RocketRod
Posts: 293
Joined: Thu Jun 02, 2005 10:06 pm
Location: Colorado Springs, CO

Post by RocketRod »

Nope, only that they are 3.3V. From what I've seen they range from 1500-10,000 mCd, and 3,000 seems to be very common. Bet mine are about 3,000. I would think that something rated at 70,000 would be way too much for a pit. I mean you want to notice them, not melt the annunciator.
Rodney

737NG Pit Builder
Some Assembly Required

vidarf
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Post by vidarf »

:D Yep, that's my thoughts too. :)

3000 mCd. Sounds very reasonable. Thanks! :)

CEL
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Location: Oslo, Norway

Post by CEL »

Do not look for luminous intensity (candela) only. The definition for Candela (cd) is the power emitted by a light source in a particular direction. If you look at the table on this site http://led.linear1.org/how-do-i-convert ... nd-lumens/ you'll notice that from a beam angle at 5 to 45 the cd/lm factor drops significantly. A LED with 3000mcd and beam angle of 5 Deg is not a good choice for annunciators.

For my amber annunciators I use a LED with a wavelength of 591nm, 25 Deg viewing angle, and a luminous intensity of 1000mcd. They are so bright that at 2.1V it is difficult to read the text on the annunciators.

So look for mcd and beam angle.

Vidar, you can buy them at ELFA. http://www.elfa.se/pdf/75/07501661.pdf

Another thing I found out while searching for the right color, is that many color-deficient people find green and yellow colors difficult to differentiate. This could be a problem with traffic signal lights. The limit in the CIE recommendations is 498 to 508nm for green and 585 to 593nm for yellow traffic lights. By raising the frequency for the yellow light, it is easier to differentiate it from green. From 591nm you move towards orange and red. That color is called amber.

Regards,
Carl

Michal
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Post by Michal »

Some things are easier with the real Korry indicators.

Others, not so easy... :roll:
Remember...140, 250, and REALLY FAST.

vidarf
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Joined: Fri May 12, 2006 11:37 am
Location: Narvik, Norway
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Post by vidarf »

Thanks, Carl! :) Got a package from ELFA today, so I know what to do now. Thank you very much! :)

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