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Topic: Pink LED's.... (Read 2872 times) previous topic - next topic

cjdelphi

I've now tried 5 different pink LED's, unlike RED, Green, Blue etc etc, the only real difference is Brightness / watt... and as for color discrepancy there is a very slight tint, but generally for all the major wavelengths including UV  they do a good job among different manufacturers.

So why is it, every single pink LED from the smallest to the largest from 1watt to 5mm (2 different types of 5mm pink I might add) 20ma and a 1206 and 06 and 08. all give off wide varying amounts of color, sometimes more orange pink, they all look different, infact what i'm going to do is solder every type of pink I have onto a board and you can see for yourself what I mean ...

This makes me curious, are all PINK led's just failed batches of UV/BLUE? so slap on a different coating and make pink?

TomGeorge

Hi cj, I think you had better google how LEDs are made, their colour is certainly not due to a filter.
A lot of physics is involved just to get red, yellow, green and the blue LED was a great breakthrough.
Also what colour would you call pink. Is there a standard pink?  lol.

Tom...  :)
Everything runs on smoke, let the smoke out, it stops running....

fungus

"Pink" is difficult - there's more than just a primary wavelength.

I'm sure there's somebody out there who'll sell you color matched pink LEDs for the right price.

No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

cjdelphi

Tom after you google search first.....

You can coat the die with a fluresence to turn the blue wavelength to white.

If you've not seen pink leds, please google for them.

cjdelphi


"Pink" is difficult - there's more than just a primary wavelength.

I'm sure there's somebody out there who'll sell you color matched pink LEDs for the right price.




I'n not sure.. i think pink ones are just faulty uv or blue (with a coating which floreses) .

fungus



I'm sure there's somebody out there who'll sell you color matched pink LEDs for the right price.


I'n not sure.. i think pink ones are just faulty uv or blue (with a coating which floreses) .


Even so, there must be somebody making them with non-"faulty" LEDs.
No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

cjdelphi

I'd like to find some non ebay ones...

Paul__B


This makes me curious, are all PINK led's just failed batches of UV/BLUE? so slap on a different coating and make pink?

Well, not quite ...


Hi cj, I think you had better google how LEDs are made, their colour is certainly not due to a filter.
A lot of physics is involved just to get red, yellow, green and the blue LED was a great breakthrough.
Also what colour would you call pink. Is there a standard pink?  lol.

True, but not quite.  Blue LEDs certainly took some time to develop.

Perhaps not a "filter", but white LEDs are in fact blue (or even violet) LEDs with a fluorescent coating, much the same as your fluorescent and CF lamps.  What intrigues me is that fluorescent lamps do degrade substantially, presumably due to the exposure of the phosphors to the far UV radiation from the mercury vapour and perhaps from the ionisation itself.  I do wonder whether white LEDs will really have the lifetime advertised though they have been available for some years now and have really become quite amazingly cheap.

Since the actual LED can only be one colour (without adding substantially to the complexity of construction, especially since the different colour technologies correspond to different threshold voltages), pink LEDs must have a mixture of phosphors (it is always a mixture, just as we have "Triphosphor" and "Quad-phosphor" fluorescent tubes) which has more red than other colours - pink is desaturated red.

But as has been said, "pink" is not a specific shade, so many things may be described as pink.  Are you troubled by variation within a batch, which there should not be, or different models of LED?

cjdelphi

Nah every bag i've got, or rather the ones from 1 batch have all be pretty much equal...

I'm yet to come across a uniform standard of "pink" they are all different which makes me suspect "hey man, did that blue LED batch cook ok?" - um no, that's ok we'll just sell them as pink!

Tomorrow i'll solder several of them and take some pictures...

cjdelphi



Gah! -  that 3rd LED which is on not (i wired up back tofront) shame, because that 5mm stands out.

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