Leds visible in daylight?

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ibrar0

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Hi, There are some advertisement boards(moving messages), in which leds are used and they glow even in dallight.
can anyone explain that is there any special type of led that is visible in daylight
or
is there any techniqe that is used so, that Messages of advertisement board glow in understandable level in day time. ordinary leds did'nt glow like that???
IF ANYONE HAVE IDEA THEN HELP ME OUT PLEASE, THANKS.
 
That's not true, the human eye is most sensitive to 555nm green and I would think those very bright superflux LEDs can be seen in direct sunlight.
 
All the traffic lights in my city have been changed to LEDs and they are clearly seen in daylight. They are shaded most of the time.
I think they are too bright at night.
 
audioguru said:
All the traffic lights in my city have been changed to LEDs and they are clearly seen in daylight. They are shaded most of the time.
I think they are too bright at night.
Click to expand...


Same thing happening in my area, LED's are getting better and better as the years roll by
 
Andy1845c said:
Well, daylight is a pretty broad term No LED is going to be too visable in direct sunlight.
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Hi Andy,

come to Thailand and learn about visibility of LEDs in bright sunlight. They are used at traffic light controlled intersections to indicate the remainder of the green phase in seconds using green LEDs and indicate the remainder of the red phase in seconds using red LEDs. The rest (transition phase) is indicated yellow. There is no sun shielding necessary. They are visible at distances of several hundred meters. (Digits are 2ft high)

Obviously they are brightness controlled, because after dawn they are dim.

Boncuk
 
Here the LED countdown timers at traffic lights are for pedestrians to see how many seconds before they get run over. Hee, hee.
They are only on the side of the street where their back is facing the sun.
 
audioguru said:
Here the LED countdown timers at traffic lights are for pedestrians to see how many seconds before they get run over. Hee, hee.
They are only on the side of the street where their back is facing the sun.
Click to expand...


Doesn't sound very friendly to me! Just to make sure: You are Candadian, aren't you? Sounds pretty much like English black humor!

Your traffic control specialists should probably take a course in Thailand how to use LEDs in traffic lights.

Btw: We have a law in Germany saying that granddads and grandmas have to cross the street with their arms streched away from their bodies. The reason: It is easier to pull them from underneath a car after being ran over.
 
Hi Hans,
In Canada the driving game is to run over an old woman pedestrian who has a big cigar in her mouth. They are hard to find.
 
audioguru said:
Hi Hans,
In Canada the driving game is to run over an old woman pedestrian who has a big cigar in her mouth. They are hard to find.
Click to expand...

That's only because most of them have been run over all ready!
 
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