I'm seeking some out-of-production discrete through-hole component LED light bars for a project. There are two different styles that I want and can not substitute. According to a couple of archived internet postings, they were reportedly manufacturer-discontinued in either the late 1970s or early 1990s, but remained somewhat available until around 2000 because at least two distributors had bought the manufacturers' remaining stocks as surplus and sold them in retail packaging.

The first type have 2 LED emitters (a.k.a. chips, or dice) per unit. Their front face measures approximately 14 mm x 7 mm (9/16 x 1/4 inch) and they're about 12 mm (1/2 inch) tall excluding leads. They're made of lightly-tinted clear epoxy, with a white-ish diffusion layer about 1-2 mm (~1/16 inch) thick at the front. The dice are about 7 mm (1/4 inch) apart, center-to-center. These were once sold in retail packaging as Cal-Pak brand "Specialty LEDs", distributed by Cal West Supply, Inc. as their part numbers CP-59 (green), CP-58 (red) and CP-60 (yellow). I know that the Cal-Pak packages were stocked in MarVac Electronics stores in the Los Angeles, California vicinity, but I do not know where else they may have been found nor how widely distributed they were. They were also offered online via Cal West's website, www.hallbar.com (defunct since early 2005). Additionally, I've been told that these LEDs have been found in "Lucky Bag" LED assortments sold primarily in Europe several years ago by Kemo Electronic. Kemo still sells such assortments but this type is apparently no longer included. I do not know the original manufacturers' part numbers nor which company(/ies) made them, though I have read a post mentioning that they were Japanese.

The second type is of similar general appearance and construction, but they have 3 emitters per unit. Their front face measures about 18 mm x 5 mm (11/16 inch x 3/16 inch) and they're about 9 mm (3/8 inch) tall excluding leads. The chips are about 5 mm (3/16 inch) apart, center-to-center. These were also sold in Cal-Pak packaging, at least in green (CP-57) and red (CP-56) colors, but apparently not in yellow. There are similar LEDs to these in current production, but not exactly alike -- the chip-to-chip spacing is 6 mm now, and the dimensions a bit smaller at 16 mm length and 8 mm height. Some time circa 2000, Cal West switched the LEDs in their Cal-Pak packaging to the current style without changing the part numbers. They also changed the 2-die style to a much smaller modern type of only 10 mm x 5 mm frontal dimension, again without changing the part numbers.

Photos linked below show the original large 2-chip style (slightly retouched image of actual LEDs in all 3 colors), the original 3-chip style (the green one is real and the others are simulated), and the Cal-Pak blister card packaging (partly simulated -- I don't know how many actually came on a card; it would most likely have been in the range of 1 to 4).

At the time of posting this, I believe I have fairly well exhausted the online possibilities presented by the popular search engines. I'm also running several daily eBay searches in English and German. So, unless you have access to data that isn't generally available to the public or crawled by the search bots, or is in another language, please don't waste your time running internet searches on my behalf. I'm after real-world info about a source or possible sources for these LEDs that probably /isn't/ already online.

I will consider your offers for any quantity. I am willing to pay international shipping costs. I'm in southern California, U.S.A.

http://www.electro-tech-online.com/a...-60-png.89802/
http://www.electro-tech-online.com/a...-xx-png.89803/
http://www.electro-tech-online.com/a...ted-png.89804/

Reply here or to a.j.franzman [ A T ] verizon [ D O T ] net. You can also view a duplicate of this posting at http://www.electro-tech-online.com/t...t-bars.143227/ and reply there.

On Monday, February 2, 2015 at 3:17:21 PM UTC-8, Scotophor wrote:
I'm seeking some out-of-production discrete through-hole component LED light bars for a project. There are two different styles that I want and can not substitute. According to a couple of archived internet postings, they were reportedly manufacturer-discontinued in either the late 1970s or early 1990s, but remained somewhat available until around 2000 because at least two distributors had bought the manufacturers' remaining stocks as surplus and sold them in retail packaging.


Consider the possibility that they were discontinued because they were
not very satisfactory. That is a LOT of epoxy in there. Stress from
the encapsulant on the die, exacerbated by the heating of the die
from the power dissipation, will promote the growth of defects, which
raises the dark current, which accelerates the wearout of the die.

More concisely, you wouldn't want to locate a cache of these ancient
parts, only to have to go through them like Kleenex.

The discussion on the other forum, where the fellow will overmold
conventionally encapsulated LEDs in the desired form factor for you,
sounds far more promising.

On Friday, February 6, 2015 at 8:45:48 AM UTC-8, wrote:
On Monday, February 2, 2015 at 3:17:21 PM UTC-8, Scotophor wrote:
I'm seeking some out-of-production discrete through-hole component LED light bars for a project. There are two different styles that I want and can not substitute. According to a couple of archived internet postings, they were reportedly manufacturer-discontinued in either the late 1970s or early 1990s, but remained somewhat available until around 2000 because at least two distributors had bought the manufacturers' remaining stocks as surplus and sold them in retail packaging.


Consider the possibility that they were discontinued because they were
not very satisfactory. That is a LOT of epoxy in there. Stress from
the encapsulant on the die, exacerbated by the heating of the die
from the power dissipation, will promote the growth of defects, which
raises the dark current, which accelerates the wearout of the die.

More concisely, you wouldn't want to locate a cache of these ancient
parts, only to have to go through them like Kleenex.

The discussion on the other forum, where the fellow will overmold
conventionally encapsulated LEDs in the desired form factor for you,
sounds far more promising.

I fail to understand how dark current is applicable here.

But if you think that's a lot of epoxy, look into the Kingbright L-885/6*DT and WP-885/6*DT, SunLED XEM*26D, and LEDtronics 23SL200*3 series, where "*" is a letter representing color code (either G, I, R or Y). These are 6-chip versions similar to the 3-chip version I'm looking for, but with the modern increased chip-to-chip spacing that I don't want. These were manufactured until very recently and are apparently still available from some industrial suppliers. There are/were also similar but even larger 8-chip versions. This strongly suggests to me that your hypothesis is erroneous -- if the ones I want were discontinued due to being unreliable simply because of their size, wouldn't even larger ones be at least as unreliable, and therefore be discontinued at the same time, or even earlier?

If I find sufficient quantity of the vintage parts and "go through them like Kleenex", I'll deal with that issue when the time comes. Let /me/ decide what I want.

As a last resort, I am prepared to undertake a similar encapsulating process to that of the fellow on the other forum, which will give me better results for less cost with respect to his method. But I haven't yet given up on obtaining sufficient quantity of the originals.

Statistically speaking, I find it hard to believe that: upon identifying the LEDs, (A) I already had two of them, unused, among my supplies, (B) I already knew someone whom I believed might also have some, which I was able to verify in minutes by browsing his website. I later obtained more than a dozen of them from him, a mix of unused examples and pulls. (C) Within days I had found another person online who sent me three more, yet (D) In the 6+ months since, I have not been able to locate even a single additional example. What are the odds that I could locate and acquire the world's entire available supply of these in such a short time, and that I already knew the person who had most of them? It boggles my mind to think that I found as many as I did so quickly, yet there now don't appear to be any more to be had, anywhere. I believe there must be more out there; it's just going to take more time and effort to discover them.

On Friday, February 6, 2015 at 3:01:05 PM UTC-8, Scotophor wrote:
On Friday, February 6, 2015 at 8:45:48 AM UTC-8, wrote:
On Monday, February 2, 2015 at 3:17:21 PM UTC-8, Scotophor wrote:
I'm seeking some out-of-production discrete through-hole component LED light bars for a project. There are two different styles that I want and can not substitute. According to a couple of archived internet postings, they were reportedly manufacturer-discontinued in either the late 1970s or early 1990s, but remained somewhat available until around 2000 because at least two distributors had bought the manufacturers' remaining stocks as surplus and sold them in retail packaging.


Consider the possibility that they were discontinued because they were
not very satisfactory. That is a LOT of epoxy in there. Stress from
the encapsulant on the die, exacerbated by the heating of the die
from the power dissipation, will promote the growth of defects, which
raises the dark current, which accelerates the wearout of the die.

More concisely, you wouldn't want to locate a cache of these ancient
parts, only to have to go through them like Kleenex.

The discussion on the other forum, where the fellow will overmold
conventionally encapsulated LEDs in the desired form factor for you,
sounds far more promising.

I fail to understand how dark current is applicable here.

Dark current is (leakage) current that does not contribute to light
output. It increases as the various crystal defects grow and propagate.
LED failure is generally defined as the point where the light output
has dropped by 50%. Selection of encapsulant can either accelerate or
retard this effect.

Statistically speaking, I find it hard to believe that: upon identifying the LEDs, (A) I already had two of them, unused, among my supplies, (B) I already knew someone whom I believed might also have some, which I was able to verify in minutes by browsing his website. I later obtained more than a dozen of them from him, a mix of unused examples and pulls. (C) Within days I had found another person online who sent me three more, yet (D) In the 6+ months since, I have not been able to locate even a single additional example. What are the odds that I could locate and acquire the world's entire available supply of these in such a short time, and that I already knew the person who had most of them? It boggles my mind to think that I found as many as I did so quickly, yet there now don't appear to be any more to be had, anywhere. I believe there must be more out there; it's just going to take more time and effort to discover them.

Sooner or later, crap tends to get flushed.

On Friday, February 6, 2015 at 5:14:16 PM UTC-8, wrote:
On Friday, February 6, 2015 at 3:01:05 PM UTC-8, Scotophor wrote:
On Friday, February 6, 2015 at 8:45:48 AM UTC-8, wrote:
On Monday, February 2, 2015 at 3:17:21 PM UTC-8, Scotophor wrote:
I'm seeking some out-of-production discrete through-hole component LED light bars for a project. There are two different styles that I want and can not substitute. According to a couple of archived internet postings, they were reportedly manufacturer-discontinued in either the late 1970s or early 1990s, but remained somewhat available until around 2000 because at least two distributors had bought the manufacturers' remaining stocks as surplus and sold them in retail packaging.


Consider the possibility that they were discontinued because they were
not very satisfactory. That is a LOT of epoxy in there. Stress from
the encapsulant on the die, exacerbated by the heating of the die
from the power dissipation, will promote the growth of defects, which
raises the dark current, which accelerates the wearout of the die.

I fail to understand how dark current is applicable here.

Dark current is (leakage) current that does not contribute to light
output. It increases as the various crystal defects grow and propagate.
LED failure is generally defined as the point where the light output
has dropped by 50%. Selection of encapsulant can either accelerate or
retard this effect.

Really? Then why do the online references seem to want to refer to dark current only in terms of photodiodes and other light-detecting (rather than emitting) components? I.E., dark current is the leakage current which flows when a light detector is detecting no light. Sure, an LED /can/ be used as a light detector, but for typical usage, the standard definition of dark current seems to be irrelevant. Can you cite references for your definition of "dark current"?

Statistically speaking, I find it hard to believe that: upon identifying the LEDs, (A) I already had two of them, unused, among my supplies, (B) I already knew someone whom I believed might also have some, which I was able to verify in minutes by browsing his website. I later obtained more than a dozen of them from him, a mix of unused examples and pulls. (C) Within days I had found another person online who sent me three more, yet (D) In the 6+ months since, I have not been able to locate even a single additional example. What are the odds that I could locate and acquire the world's entire available supply of these in such a short time, and that I already knew the person who had most of them? It boggles my mind to think that I found as many as I did so quickly, yet there now don't appear to be any more to be had, anywhere. I believe there must be more out there; it's just going to take more time and effort to discover them.

Sooner or later, crap tends to get flushed.

Are you making assumptions again, or do you have personal experience with the LEDs I'm seeking? Also, I can direct you to several collectors and sellers of some of the earliest commercially-made LEDs, which are IMO far more suited to be labeled as "crap", based purely upon light output and longevity, than those of my current quest. If people collect that junk, then why not some that are brighter and more unusual?

On Saturday, February 7, 2015 at 12:19:48 AM UTC-8, Scotophor wrote:
On Friday, February 6, 2015 at 5:14:16 PM UTC-8, wrote:
On Friday, February 6, 2015 at 3:01:05 PM UTC-8, Scotophor wrote:
On Friday, February 6, 2015 at 8:45:48 AM UTC-8, wrote:
On Monday, February 2, 2015 at 3:17:21 PM UTC-8, Scotophor wrote:
I'm seeking some out-of-production discrete through-hole component LED light bars for a project. There are two different styles that I want and can not substitute. According to a couple of archived internet postings, they were reportedly manufacturer-discontinued in either the late 1970s or early 1990s, but remained somewhat available until around 2000 because at least two distributors had bought the manufacturers' remaining stocks as surplus and sold them in retail packaging.


Consider the possibility that they were discontinued because they were
not very satisfactory. That is a LOT of epoxy in there. Stress from
the encapsulant on the die, exacerbated by the heating of the die
from the power dissipation, will promote the growth of defects, which
raises the dark current, which accelerates the wearout of the die.

I fail to understand how dark current is applicable here.

Dark current is (leakage) current that does not contribute to light
output. It increases as the various crystal defects grow and propagate.
LED failure is generally defined as the point where the light output
has dropped by 50%. Selection of encapsulant can either accelerate or
retard this effect.

Really? Then why do the online references seem to want to refer to dark current only in terms of photodiodes and other light-detecting (rather than emitting) components? I.E., dark current is the leakage current which flows when a light detector is detecting no light. Sure, an LED /can/ be used as a light detector, but for typical usage, the standard definition of dark current seems to be irrelevant. Can you cite references for your definition of "dark current"?


Fine. "Nonradiative." Only takes three times the keystrokes.

Statistically speaking, I find it hard to believe that: upon identifying the LEDs, (A) I already had two of them, unused, among my supplies, (B) I already knew someone whom I believed might also have some, which I was able to verify in minutes by browsing his website. I later obtained more than a dozen of them from him, a mix of unused examples and pulls. (C) Within days I had found another person online who sent me three more, yet (D) In the 6+ months since, I have not been able to locate even a single additional example. What are the odds that I could locate and acquire the world's entire available supply of these in such a short time, and that I already knew the person who had most of them? It boggles my mind to think that I found as many as I did so quickly, yet there now don't appear to be any more to be had, anywhere. I believe there must be more out there; it's just going to take more time and effort to discover them.

Sooner or later, crap tends to get flushed.

Are you making assumptions again, or do you have personal experience with the LEDs I'm seeking? Also, I can direct you to several collectors and sellers of some of the earliest commercially-made LEDs, which are IMO far more suited to be labeled as "crap", based purely upon light output and longevity, than those of my current quest. If people collect that junk, then why not some that are brighter and more unusual?

Crap is stuff that appears only in blisterpacks, and then gets
surplused. Not like having some, say, Monsanto LEDs.

On Saturday, February 7, 2015 at 3:19:48 AM UTC-5, Scotophor wrote:
On Friday, February 6, 2015 at 5:14:16 PM UTC-8, wrote:
On Friday, February 6, 2015 at 3:01:05 PM UTC-8, Scotophor wrote:
On Friday, February 6, 2015 at 8:45:48 AM UTC-8, wrote:
On Monday, February 2, 2015 at 3:17:21 PM UTC-8, Scotophor wrote:
I'm seeking some out-of-production discrete through-hole component LED light bars for a project. There are two different styles that I want and can not substitute. According to a couple of archived internet postings, they were reportedly manufacturer-discontinued in either the late 1970s or early 1990s, but remained somewhat available until around 2000 because at least two distributors had bought the manufacturers' remaining stocks as surplus and sold them in retail packaging.


Consider the possibility that they were discontinued because they were
not very satisfactory. That is a LOT of epoxy in there. Stress from
the encapsulant on the die, exacerbated by the heating of the die
from the power dissipation, will promote the growth of defects, which
raises the dark current, which accelerates the wearout of the die.

I fail to understand how dark current is applicable here.

Dark current is (leakage) current that does not contribute to light
output. It increases as the various crystal defects grow and propagate.
LED failure is generally defined as the point where the light output
has dropped by 50%. Selection of encapsulant can either accelerate or
retard this effect.

Really? Then why do the online references seem to want to refer to dark current only in terms of photodiodes and other light-detecting (rather than emitting) components? I.E., dark current is the leakage current which flows when a light detector is detecting no light. Sure, an LED /can/ be used as a light detector, but for typical usage, the standard definition of dark current seems to be irrelevant. Can you cite references for your definition of "dark current"?

Statistically speaking, I find it hard to believe that: upon identifying the LEDs, (A) I already had two of them, unused, among my supplies, (B) I already knew someone whom I believed might also have some, which I was able to verify in minutes by browsing his website. I later obtained more than a dozen of them from him, a mix of unused examples and pulls. (C) Within days I had found another person online who sent me three more, yet (D) In the 6+ months since, I have not been able to locate even a single additional example. What are the odds that I could locate and acquire the world's entire available supply of these in such a short time, and that I already knew the person who had most of them? It boggles my mind to think that I found as many as I did so quickly, yet there now don't appear to be any more to be had, anywhere. I believe there must be more out there; it's just going to take more time and effort to discover them.

Sooner or later, crap tends to get flushed.

Are you making assumptions again, or do you have personal experience
with the LEDs I'm seeking?

Well, then give us a cost.

How much will you spend for what you want? Because, otherwise, yes, we're getting into possibly pointless speculation here as opposed to comparing and contrasting the pros/cons - which is what I think you are preferring. In that regard, cost either can be an issue or not.

Whether this is business or a hobby for you, other people are trying to give you recommendations without anyone having specified an exact cost (above which you don't want to pay). If you are willing to devote endless dollars, then companies can make you an exact custom order. On the other hand, if you are straight off of the street looking for ideal scrap, then say so.

On Saturday, February 14, 2015 at 8:43:28 AM UTC-8, wrote:
Well, then give us a cost.

How much will you spend for what you want? Because, otherwise, yes, we're getting into possibly pointless speculation here as opposed to comparing and contrasting the pros/cons - which is what I think you are preferring. In that regard, cost either can be an issue or not.

Whether this is business or a hobby for you, other people are trying to give you recommendations without anyone having specified an exact cost (above which you don't want to pay). If you are willing to devote endless dollars, then companies can make you an exact custom order. On the other hand, if you are straight off of the street looking for ideal scrap, then say so.

Thanks, everyone, for the recommendations. Although I didn't ask for recommendations, I have considered them all.

Cost is definitely an issue. This is a hobby project for me but I'm not the only person interested. For small quantities, say 20 pieces or fewer, I might pay up to USD $5 each. The reason I didn't mention a price previously is, once there is a price mentioned, it's very difficult to find someone who will sell for less than that... even if they previously would have sold the same item for 50 cents each, without having a price reference available.

As the cost per piece goes down, I might buy larger quantities, up to several hundred pieces. This would enable me to offer either multiple copies of the project item, or the surplus LEDs beyond my own needs, to others in the hobby community. I believe that it will not be cost-effective to fund a new production run of custom manufactured LEDs for such small numbers. I doubt any manufacturer would bother for less than 10,000 pieces (or the equivalent cost thereof, for any lesser quantity).

I object to your word choice when you wrote, "if you are straight off of the street looking for ideal scrap." That phrase is loaded with negative connotations. I already wrote that I was looking for vintage parts. This should have been enough for you to infer that my quest is not for business purposes.