Cheap bare 385nm UV LED

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TheOnlyDocc
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I like it! The 55° emission dome is even better for me. So i am happy. And i will not complain about getting a newer generation with more output.
I send a PM to all on the list.
And i contacted the seller and asked for the flux and voltage bin. But ~1400mW at ~700mA is dam hot! My DD tripple could get really hot Evil . I am eager to see what this led can do on a copper MCPCB at 1 amp+. If i had to guess i would say that the tripple could get easy 4-5W real 385nm output.
Maybe i should get one of this stickers for the light Big Smile

Cheap bare 385nm UV LED (http://budgetlightforum.com/node/54674)

Q8 Dual footprint, quad LED copper DTP LEDboard interest List (http://budgetlightforum.com/node/54758)

alpg88
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djozz wrote:

The newer generation with better output (I would still have to test what the real world performance is) is pretty cool of course. But that it is the narrow emmission version may be not cool for some.

does it mean they wont work as good with tir? i’m planing to use PMMA triple from ledil, i used it before with 365nm leds. but those had 120*

djozz
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It will be an surprise how they behave in a TIR. I do have a Ledil Cute and a 32mm Noctigon board I could check, but it will take another week before I actually have time to do the experiment.

TheOnlyDocc
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I thought that plastic lenses/TIR are not the best way to go if you use UV leds. Also AR coating on glass lenses. Thats the reason why i ordered new lenses for my Wall-E light (against the description the light arrived with cheap plastic lenses) one with AR coating for the MC-E led and one without for the UV tripple.

Cheap bare 385nm UV LED (http://budgetlightforum.com/node/54674)

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Jensen567
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I might have to grab some of these LEDs and throw together a P60 quad drop in, no optics, just bare emitters, would be handy for checking for leaks with fluorescent dyes and other close up stuff, which is really all I do with UV anyhow.

Is the new version available on Ali yet?

alpg88
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TheOnlyDocc wrote:
I thought that plastic lenses/TIR are not the best way to go if you use UV leds..

they are not, vast majority of them, but those made with PMMA are ok. unlike polycarb pmma can work with band as low as 365nm.

TheOnlyDocc
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Dam i could have fit a quad copper mcpcb in the Wall-E light. Mhh but now i have a tripple board with small tripple reflector here. No no no it is tempting but no i will not do it. Facepalm

@Jensen567
The shop on Aliexpress is selling these leds on Alustar 10pcs/lot at $12.75 (https://de.aliexpress.com/item/10pcs-3W-3535-High-Power-LED-UV-Light-Chi...).
Normal price at this shop is 15$/lot.

Cheap bare 385nm UV LED (http://budgetlightforum.com/node/54674)

Q8 Dual footprint, quad LED copper DTP LEDboard interest List (http://budgetlightforum.com/node/54758)

djozz
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TheOnlyDocc wrote:
Dam i could have fit a quad copper mcpcb in the Wall-E light. Mhh but now i have a tripple board with small tripple reflector here. No no no it is tempting but no i will not do it. Facepalm

I’m not sure that there is a PMMA Ledl optic for the quad boards used here on BLF, these quad boards are made for Carclo 10622 optics which are made of polycarbonate that has a cut-off at 400nm.
TheOnlyDocc wrote:
@Jensen567 The shop on Aliexpress is selling these leds on Alustar 10pcs/lot at $12.75 (https://de.aliexpress.com/item/10pcs-3W-3535-High-Power-LED-UV-Light-Chi...). Normal price at this shop is 15$/lot.

But aparently you do not know what you will get, I’m pretty sure that if you buy these leds on the 20mm star it is still the older generation led (which perfroms fine btw) with the 120 degrees dome because they still have already produced stock, and not the newer gen. with 55 degrees dome like we received as bare leds now.

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What are the plastic lenses made of in the cheap Chinese zoomies? I’m thinking with the tighter 55° emission dome, an aspheric is better than a reflector. But, I can’t afford nice lights with glass lenses! Silly

Reason is not automatic. Those who deny it cannot be conquered by it. Do not count on them. Leave them alone.
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djozz
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DavidEF wrote:
What are the plastic lenses made of in the cheap Chinese zoomies? I’m thinking with the tighter 55° emission dome, an aspheric is better than a reflector. But, I can’t afford nice lights with glass lenses! Silly

Polycarbonate, and having measured a few for 365nm transparancy I can confirm that they block it. The small On The Road zoomie (i3) has a glass lens though, that could be a nice host for this led.
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djozz wrote:
DavidEF wrote:
What are the plastic lenses made of in the cheap Chinese zoomies? I’m thinking with the tighter 55° emission dome, an aspheric is better than a reflector. But, I can’t afford nice lights with glass lenses! Silly

Polycarbonate, and having measured a few for 365nm transparancy I can confirm that they block it. The small On The Road zoomie (i3) has a glass lens though, that could be a nice host for this led.

figures… Tired

Reason is not automatic. Those who deny it cannot be conquered by it. Do not count on them. Leave them alone.
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Are there any left? How much is UK shipping?

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NeoGeo wrote:
Are there any left? How much is UK shipping?

TheOnlyDoc will know soon how many are left. The shipping is 1.70 euro.
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You know what I just thought of? If these are not the exact same emitters, then how do we know if they are even the same wavelength as the ones we asked for? Is the original LG packaging present and labeled appropriately?

Reason is not automatic. Those who deny it cannot be conquered by it. Do not count on them. Leave them alone.
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DavidEF wrote:
You know what I just thought of? If these are not the exact same emitters, then how do we know if they are even the same wavelength as the ones we asked for? Is the original LG packaging present and labeled appropriately?

No, it is a matter of trust. I did check their earlier LG leds and they were dead-on 385nm. I could check these too but will not bother actually, it is not that the 385nm ones are more special or expensive than the 395 or 405 ones, I think that they know their leds but just don’t understand their customers.
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djozz wrote:
DavidEF wrote:
You know what I just thought of? If these are not the exact same emitters, then how do we know if they are even the same wavelength as the ones we asked for? Is the original LG packaging present and labeled appropriately?

No, it is a matter of trust. I did check their earlier LG leds and they were dead-on 385nm. I could check these too but will not bother actually, it is not that the 385nm ones are more special or expensive than the 395 or 405 ones, I think that they know their leds but just don’t understand their customers.

That’s good enough for me. As many LEDs as you’ve tested over the years, if you can trust them, so can I. I don’t have any particular attachment to any particular wavelength anyway. I’m just buying these to play with. Big Smile

Reason is not automatic. Those who deny it cannot be conquered by it. Do not count on them. Leave them alone.
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alpg88
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on the pic the dome looks taller than normal? is it the case, or just optical illusion?

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So i got answere from the seller.

Like we could expect it is the lowest flux bin. But also the lowest Voltage bin with 3,2-3,4V. This should help to get a little bit more out of the leds.
At the moment there is only one person that has not payed and did not answere the PM. But i want to wait till tomorror. If i did not hear from him till then djozz and NeoGeo can have the leds. I do not know how much djozz or NeoGeo needs but that problem can be solved.

Cheap bare 385nm UV LED (http://budgetlightforum.com/node/54674)

Q8 Dual footprint, quad LED copper DTP LEDboard interest List (http://budgetlightforum.com/node/54758)

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I’d be interested in 1-3.

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TheOnlyDocc wrote:
So i got answere from the seller.

Like we could expect it is the lowest flux bin. But also the lowest Voltage bin with 3,2-3,4V. This should help to get a little bit more out of the leds.
At the moment there is only one person that has not payed and did not answere the PM. But i want to wait till tomorror. If i did not hear from him till then djozz and NeoGeo can have the leds. I do not know how much djozz or NeoGeo needs but that problem can be solved.


So, how does this lowest bin of the newer gen compare with the LEDs we were originally expecting? Since you have the info now for these LEDs, I’m just curious what the output difference is. Innocent

Reason is not automatic. Those who deny it cannot be conquered by it. Do not count on them. Leave them alone.
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All leds are paid for. Sorry for all that are to late.
We do not know how much output they produce above 700mA (out of specs) but in spec there is not much difference in output to the old one he tested. Now we have to wait for djozz test to see how they perform above factory settings.

Cheap bare 385nm UV LED (http://budgetlightforum.com/node/54674)

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djozz
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It is a pity that these are the lowest bin possible, I hoped for a more average bin. It should still be ~100 mW above the older generation led.

I do not know how well they perform above the specs. the thermal resistance is better than the older led, but I found in 365nm leds that the output of the die has a sharp output limit regardless of temperature, so temperature may not be the bottleneck. On the other hand, 385nm leds have a different type of die than 365nm leds so may have other characteristics as well.

In other words: only a test can tell, and I hope to check the led this weekend.

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TheOnlyDocc has given me the addresses to where the leds will be sent , and try to put them in the mail as soon as I have time.

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Thanks djozz!

Reason is not automatic. Those who deny it cannot be conquered by it. Do not count on them. Leave them alone.
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TheOnlyDocc
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I asked the seller if he could get these LEDs in a higher flux bin (like HP15). If he is able to source the LEDs for a good price i maybe will do a second order round. But only if he really can get one of the higher bins.

Cheap bare 385nm UV LED (http://budgetlightforum.com/node/54674)

Q8 Dual footprint, quad LED copper DTP LEDboard interest List (http://budgetlightforum.com/node/54758)

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Look forward to hearing what they say.

TheOnlyDocc
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The seller has to many LEDs in stock at the moment. But next time he has to restock he will try to get some with higher flux bin. If he can get them he will let me know.

Cheap bare 385nm UV LED (http://budgetlightforum.com/node/54674)

Q8 Dual footprint, quad LED copper DTP LEDboard interest List (http://budgetlightforum.com/node/54758)

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TheOnlyDocc wrote:
The seller has to many LEDs in stock at the moment. But next time he has to restock he will try to get some with higher flux bin. If he can get them he will let me know.

Thanks for checking. Please keep us updated here.

Reason is not automatic. Those who deny it cannot be conquered by it. Do not count on them. Leave them alone.
-Ayn Rand

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I have sent 37 leds in the mail on friday.

And yesterday evening I did an output test on the led (will call it the 4th gen. LG 3535 UV led). Do not expect anything as accurate as my white light tests, my method of testing UV leds has many imperfections leading to probably large errors (method here). Errors are caused by fluorescent bleaching of the used copier paper, variation of fluorescent die in the paper, but also higher than average output drop upon warming up of UV leds. On top of that the new led has a vastly different emission angle which also will cause extra error the way the led illuminates the paper. The measured voltages however are as correct as my normal led tests.

So I was quite surprised how close this led tested to the 3rd gen. version I tested 2 years ago.

The main difference is the much lower voltage of the 4th gen. led which makes even this lowest bin more efficient than the 3rd gen. that was tested, so it can not be direct driven on a single li-ion anymore but must be regulated (i.e. by a 7135 based lineair driver). And like the 3rd gen. led the sweetspot for me is 1.5A.

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I expected a low Vf at the V1 Voltage bin but this is really low. Mhh the idea to use a FET on the MELD-X Driver for the UV channel is no longer a good option. And i do not think that all the parts will fit on one PCB. Not if i want to go up to 4-4,5A on the UV channel (tripple UV) and 700mA on every other channel. This would require 20*7135 chips.

Did anybody know a source for the good “Raptor claw” 7135chips? I have a few left but they will not last long. And with more low Vf LEDs getting on the market i want to stock up a few if i can get them.

Cheap bare 385nm UV LED (http://budgetlightforum.com/node/54674)

Q8 Dual footprint, quad LED copper DTP LEDboard interest List (http://budgetlightforum.com/node/54758)

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