Want amber led that will mimic the color of HPS lamp?

[anuragwap]

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[idleprocess]

making them very similar to HPS orange, one of my favorite colors.

I've got so say you're the only person I've ever encountered that likes HPS orange...



Looking at the spectrum of HPS, it appears to have its primary spike at 570nm, with sequentially smaller spikes at 590, 605, and 630nm. A LED close to 595nm might replicate what you saw.

[blasterman]

High pressure sodium is rarely a perfectly monochrome wavelength and often has some minor bands mixed in.

The LED in question is either using a special filter, or is just a high bin amber for a specialty application.

[anuragwap]

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[RoGuE_StreaK]

Are you sure it's not the car's lense that's making the difference? In my car for example, the rear blinkers (aka indicators, aka turn signals, etc) are a pale yellow/amber, despite my best efforts to put in pure amber LEDs. This seems to be because of the clear diffuser in the light assembly, which seems to turn everything a lot paler than it is by itself; I think I'm going to need to add some red filter or something to try to get the colour right!
Couldn't find a photo with the blinkers on, but here's what the rear lights look like:
http://upload.wikimedia.org/wikipedi...n_wagon_01.jpg
http://www.eddywreckers.com/images/u...te-w_sw_tl.jpg

[anuragwap]

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[RoGuE_StreaK]

I dunno why, just an observation; my LEDs show up well and truly amber when unhoused, but when behind the lense they look really pale. I was unimpressed by the colour given by the amber-coated incandescent that's currently in there, bought some amber LEDs to try to rectify it, only to find the exact same issue (plus they didn't fit through the housing body fully, so half of the side-emitting LEDs weren't actually visible, hence back to the incandescent)

Sorry I couldn't be of help

[3000k]

I would love to have an HPS LED. Personally I will be bummed when HPS are phased out.

[pretmetled]

I've got so say you're the only person I've ever encountered that likes HPS orange...

Looking at the spectrum of HPS, it appears to have its primary spike at 570nm, with sequentially smaller spikes at 590, 605, and 630nm. A LED close to 595nm might replicate what you saw.

If you're really desperate for that HPS orange and as such mixing multiple leds is acceptable, maybe a combination of a 570 nm + a 590 nm led would do the trick? Say for example a 1206KGCT + 1206KYCT combo?

[jtr1962]

I think the phosphor-converted amber Rebel comes pretty close to HPS. It's a somewhat wider spectrum than "regular" amber, and the color appears more like HPS than regular amber (which tends to look like LPS). The dominant wavelength is roughly 591 nm according to the datasheet.

[hank]

Another amber fan here.

[anuragwap]

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[RoGuE_StreaK]

You didn't happen to take note of what make/model the car was? Might be able to find specifics from the car maker themselves, or on a related car forum.

[Kinnza]

About two years ago, I saw some models of PC amber LEDs by Intematix. They were avalaible on a wide range of LED powers, as they used a ceramic base with low power blue chips arrays, customizable on power. Not a product they sell directly or retail, but for custom OEM orders. Likely it fits well with the LED you saw. Overall color tone was pretty similar to HPS orange glow, as in general PC ambers.

Those LEDs were domeless. Checking if the LEDs you saw have dome shaped lens or not would help a lot on narrowing down the actual model LED.

[calipsoii]

Hoo boy, you're gonna have a heck of a time trying to find an LED with a spectrum like this:
http://upload.wikimedia.org/wikipedi...p_Spectrum.jpg

If you definitely want it in LED, best to pick a dominant wavelength that you find pleasing (like 590nm) and go with it. Otherwise maybe you can find a small HPS unit that can be powered by a battery or something.

If there were 10 of them packed in, were they 5mm? Something like this?

[blasterman]

It's possible that we also might be looking at a rare 'pink' LED , or a specific mix weighted more towards the orange end. I've seen some where the color is very muted and similiar to pink slanted HPS. Likely blue plus amber and red phosphor.

[anuragwap]

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[Neondiod]

I've find that mixing one cool white (about 6000K) and one amber led behind an opaque layer will be quite similar to HPS light. I find this trying to get warm white (incandescent looking) but the result was not to my liking, -it looked too much, pink HPS light for me

I like the even more hated LPS light.

[Kinnza]

PC amber LEDs already has CIE coordinates pretty close to HPS, at least, to pure HPS lamps (not blue enriched, the ones you are calling with a pinkish tone as compared with the typical streetlight; or maybe you are refering to a near end of life HPS bulb, which tend to get a very noticiable pink tone).

PC amber Rebel has bins color between x=0.55 to 0.581 and y=0.411 to 0.437. Roughly, center on bin area at about X=0.565 and y=0.423, for CCT of 1900K. They are binned at Tj=25ºC, but at the normal higher operating temp, they tend to increase y and decrease x, driving CCT up.

Most HPSs has CCT between 2000 and 2400K, with x between 0.5 and 0.55 and y between 0.41 and 0.44. So actually, overall tone of normal working PC amber LEDs is very close of that of the warmer HPS.

Just getting a batch of PC amber LEDs with slightly lower phosphor concentration, allowing for a small peak on the blue, would allow to a CCT on the same range than HPS, with similar coordinates, and a little less phosphor, close to the pinkish HPSs, which are over 2500K.

[yuandrew]

VW/Porsche/Audi ?

I saw a Cayenne today with LED front turn signals that were an orange-white color

[EricB]

There's a kind of "soft white" LED that appears to be lower in Kelvins than the 2700's that are out now, and when seeing a bunch of them together, they resemble HPS. I have never been able to find any info on them (like how many K's), nor have I seen them sold in any form yet, but I've seen rope lights of them as store window displays, and this store is covered with them at Christmas time: http://maps.google.com/?ll=40.760726...29577951308144
(Next to the 2700 and higher LED's on nearby stores, they really do look "copper" or similar to HPS).
Perhaps they are starting to use them as incandescent replacements for cars? (Where the 6000K's alredy used for the white "Reverse" lights would distort the colors of the red or amber lights).

[och]

I though HPS was a yellowish color, LPS was orange?

[Canuke]

I've find that mixing one cool white (about 6000K) and one amber led behind an opaque layer will be quite similar to HPS light. I find this trying to get warm white (incandescent looking) but the result was not to my liking, -it looked too much, pink HPS light for me

This. A few years ago I went camping on Thornhill Broome beach in California, and the park ranger shack had an outside area light that looked like HPS, but on close examination I noticed it was full of cool white and amber LED's.

The *blue* spike is what gives HPS its characteristic color, in combination with the yellow band it shares with LPS. The varying shades of HPS are a function of variations in that blue band. If you get a CIE color diagram and draw a straight line between 590nm and about 450 nm or so (I don't know exactly where that blue is), the line should cross all those shades of orange and pink that HPS can take on.

[Canuke]

EricB: I Was going to say that I've never seen those, but upon reflection I think I have. I was in a restaurant (Fleming's in Las Vegas, I think) and they had those little battery-operated LED votive candles for decor. But these were not emitting that usual amber, the light actually looked much more like the warm orange of an actual flame. I tried to find out where they got them, but nobody knew.

I don't know whether these emitters are rare or expensive, but they sure would be a lot more appealing in rope lights and other decorative applications than monochromatic amber (or its Halloween orange counterpart) could ever be.

[Canuke]

EDIT: I think I found the source, they were probably 5mm amber leds from Nichia, it is the only company that makes 5mm PC amber, evident from higher V_f and wider SPD curve in the datasheet of NSPA510BS. (But puzzlingly their x,y value is still very near the spectral boundary!)

Brookstone has (or had) their own keychain lights that used phosphor-based yellow and pink emitters. The yellow had a much more "lemony" quality to it that monochrome yellow does; I think that most yellows we see in the world are actually rather broad in their reflectance spectra, including from red through to green -- not-blue, in other words.

[EricB]

I though HPS was a yellowish color, LPS was orange?

I meant HPS (I call it "peach" color, as it's pale and pinkish, basically whitish orange; whitish from having the blue in it, as Canuke said). I don't know why I got that crossed with LPS, which is the monochrome amber (which is yellowish orange, but closer to yellow).

EricB: I Was going to say that I've never seen those, but upon reflection I think I have. I was in a restaurant (Fleming's in Las Vegas, I think) and they had those little battery-operated LED votive candles for decor. But these were not emitting that usual amber, the light actually looked much more like the warm orange of an actual flame. I tried to find out where they got them, but nobody knew.

I don't know whether these emitters are rare or expensive, but they sure would be a lot more appealing in rope lights and other decorative applications than monochromatic amber (or its Halloween orange counterpart) could ever be.

Candle LEDs usually are amber, but sometimes the illumination of the white plastic surrounding it makes the amber look paler like real flame. We have one of those bathroom scent candles, and when you're looking at the [diffused] light through the plastic, it does look like real flame color. When you look directly at the LED, it's amber, but also, perhaps because these things are usually used in the dark, I think that could also affect it. I noticed it tends to look paler. Might have to do with our eyes. (Like if you look at red for a long time, and then look at 590 amber (LED or LPS), it suddenly looks greenish "lemon" yellow instead of amber!)

Or maybe it could be what I was referring to. Trying to remember what other color I've ever seen those little tea lights in (I do know I've seen an RGB one). I don't think I've seen the copperish (HPS-like) lights anywhere but those decorations.

[anuragwap]

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[Canuke]

ERicB: Our ability to distinguish saturation falls off at the dark limits of color vision; that amber is closest of the monochrome colors to candle light, so it still "works" fairly well when seen through the candle wax (where it mixes with ambient illumination reflecting off the wax). However, the LED candles I was discussing were definitely not amber, as I stared right at the "flame" and there was definitely blue light in it.

[EricB]

I don't know what that was, then. It could be the "copper" light I was talking about. I really can't tell looking it up, because when they say "amber" or "flame colored", you can't tell whether it's 590 monochrome, or the color you're looking for, or whatever else.

I guess eventually these will become more available (like I first saw really good 2700K LED's back in '05 in the LEDEffects showroom (when I was preparing to buy the DingDotz back then), and it's not really until the last three or so years that you can really see or buy 2700's everywhere. (First, you had the pale 3500 ones).

As for the Brookstone keychain, I saw the phosphor yellow (but not the pink) years ago, and yes, it's a nice lemons yellow pretty much like FFFF00 on a monitor. That's the only place I've ever seen it to date, and wonder why they never caught on anywhere. (You do see the pinks more, but never yellow).

What would be the closest color on the monochrome spectrum? Around 580? (570 green is close as it is. Maybe 575, then). I wonder why you don't see those wavelengths in LED.