4 more 365nm UV-leds tested

adam7027 · 2018-09-29T23:58:21.000Z

moderator007:

TheOnlyDocc:

I will test them when the leds arrive. I have ordered two from KD. One for me and one for my neighbors Convoy M2.

I got one from KD a month ago. Unsoldered the UV leds on to a series mcpcb and used a modified H1-A driver at about 1.5a to each led. I used the optics that came with it in a convoy S2+. Didn’t seem to put out much UV, my convoy Nichia was brighter. . I asked Djozz if he knew what was up with it. He told me you can’t use optics, that most of the UV light is absorbed in the optics :person_facepalming: . Well that explains my problem. Took the light back apart and found the Z5’s were cooked and the optics had melted :cry: . Ordered a triple aluminum reflector that Djozz suggested and still waiting on the new Z5 board to get here. learned my lesson, Don’t use optics with UV leds.

moderator007:

I’m not sure of which optics might work or will not work. But I do know if you use the optics that come from KD with a triple Z5 led it will melt and produce about as much light as a single 5mm led.

Whoa. I was into planning to make the same mistake… I planned to install the Z5 triplet from Kaidomain into a Jaxman E2L host, with a 6×7135 3 mode linear driver (700mA for each led).
EDIT Here kaidomain says, that the support team tested the max. forward current for a single LED, which was in the 1.0-1.2A range - you drove them to 1.5A each - could be this a significant factor in the event of them getting cooked?

moderator007:

http://kaidomain.com/S027437-Triple-Seoul-Viosys-Ultraviolet-UV-365nm-LED-Emitter-with-20mm-x-1mm-DTP-Copper-MCPCB-Parallel?search=uv%20led&page=2
.
This is the only triple 20mm reflector I have seen and you have to buy the host, I have yet to finish the build as my new board from KD hasn’t arrived yet.
Page Not Found - Aliexpress.com
.
I don’t know if the reflector and the board will even match up yet. Figured I would make it work some how if it didn’t.

Thank you guys for these info, it was a ‘life saver’ to me.

I will wait for your modding attempt then, but maybe we could ask BanL from Kaidomain, if he could get that reflector separately.

adam7027 · 2018-09-29T23:54:21.000Z

By the way, do you know, what justifies the big price difference between the Luminus SST-10 UV and the Seoul Viosys Z5?

djozz · 2018-09-30T00:14:28.000Z

adam7027:

By the way, do you know, what justifies the big price difference between the Luminus SST-10 UV and the Seoul Viosys Z5?

No, not really. In the niche of these UV-leds there is not the tough competition of white leds that are sold in the billions. So I guess that the selling prices may be more random, more related to actual production costs and less to what the competition sells them for.

moderator007 · 2018-09-30T02:26:23.000Z

The triple aluminum reflector will not work with a triple optic copper board, the led pad spacing is different. The only way I See to use the reflector is to reflow the factory leds off the factory board and reflow the Z5’s on, but the factory board is aluminum. So the Z5’s couldn’t be driven to hard or they might cook. Kind of defeats my purpose of using a boost driver and under drive the leds. Close to the same output might be achieved using a single led and a copper board. Plus the factory board is wired with all the leds sharing the same ground and each has its on positive. That’s how the driver switches between leds. The factory aluminum board would need some modifications to run all the leds in parallel but wouldn’t be that hard. I planned on using a modified H1-A boost driver and use them in series. I’m either going to try parallel with factory board and a different driver or hunt for a glass Aspherical lens to fit the convoy s2 and use my series wired board with the H1-A. Not sure which way I wanna go with this mod.

adam7027 · 2018-10-03T21:52:42.000Z

Until I find a good way to use the SeoulViosys triplet from kaidomain, I will take a plan B.

I will purchase LG UV LED from Simon. Do you think, that this driver could be good for getting into the sweet spot amperage for that LED, or I should rather use a 4(or 5)×7135 driver?

adam7027 · 2018-11-06T20:35:30.000Z

Hello djozz,

You might want to test this as well

New LG UV LED is available from Convoy store @ AliExpress. Bigger light emitting surface (good for floodier lights and OP reflectored S2+ flashlights), and over double (1.5A) max rated current compared to the LG led already available there (0.7A).

djozz · 2018-11-06T21:43:46.000Z

adam7027:

Hello djozz,

You might want to test this as well

New LG UV LED is available from Convoy store @ AliExpress. Bigger light emitting surface (good for floodier lights and OP reflectored S2+ flashlights), and over double (1.5A) max rated current compared to the LG led already available there (0.7A).

Woohoo, I’ve been waiting for that led to become available for mere mortals for more than 2 years. I ordered it.
Thanks for the heads-up! :+1:

wintermute76 · 2018-11-06T23:00:58.000Z

adam7027:

Hello djozz,

You might want to test this as well

New LG UV LED is available from Convoy store @ AliExpress. Bigger light emitting surface (good for floodier lights and OP reflectored S2+ flashlights), and over double (1.5A) max rated current compared to the LG led already available there (0.7A).

Think I might pick up a few as well, upgrade the Convoy S2 and 4x for my Terminator mod, the 16mm star is perfect.
I had found some 10W ones on eBay, but they are 20mm stars.

Now to figure out how to dial back the current so it doesn’t cook them.

Kame_Sennin · 2018-11-07T21:42:43.000Z

What might be good a good host for this new LG UV in order to run it at 1.0-1.5A for extended time ?

Would have to use a front lens with a size for which zwb2 is easily available.

What are your thoughts about that ? Is the S2/S2+ good enough ?

djozz · 2018-11-07T23:05:13.000Z

Kame Sennin:

What might be good a good host for this new LG UV in order to run it at 1.0-1.5A for extended time ?

Would have to use a front lens with a size for which zwb2 is easily available.

What are your thoughts about that ? Is the S2/S2+ good enough ?

This led has a fairly big die so a UV-thrower (however useful that is) may not the best purpose. So yes, an S2+ could be good, or anything with a good heat path because UV leds are not as tough as white leds.

AnhTran · 2019-02-21T05:16:23.000Z

Could anyone good at math and physics help me comparing the level of UV intensity from direct sunlight and the UV intensity from these UV flashlight ( such as 1m distance direct from the flashlight, or the UV that is reflected from a white wall at 1m distance).
I want to play with UV but i always fear that the reflect light would be too dangerous for my eyes and skin. Thanks

djozz · 2019-02-21T09:29:14.000Z

There is more going on than just the intensity, too much to compare sunlight with 365nm flashlights.

Sunlight emits a broad band of UV from 300-400nm, woth the shortest wavelengths more harmful than the ones closer to 400nm, and second, it cones with a huge amount of visible light that cause your pupils to close as far as possible, and looking straight into the sun is impossible.

A 365nm flashlight emits a very narrow wavelength band in a less harmful longer wavelength, but your eyes, seeing nothing, does not respond by closing the pupils, they stay wide open, admitting lots of light in. And looking straight into a 365nm flashlight is entirely possible.

Personally, my eyes have a clear warning system: my retina start hurting with UV light, once I knew the feeling I also recognise small doses.
That never happens with sunlight.

AnhTran · 2019-02-21T09:43:09.000Z

Thanks for your explaination, what do you think is more harmful for skin, direct sunlight or reflected UV light when you play with UV flashlight in a room?

djozz · 2019-02-21T12:04:43.000Z

Sunlight is much worse, 365nm UV has hardly any effect. The problem is your eyes.

TBone · 2019-02-21T17:57:07.000Z

Here is a diagram that shows how sensitive human skin is to different wavelengths (green line; from Wikipedia).

The red curve is the sunlight and the blue curve is how effectively bad each wavelength is for human skin.
The blue is calculated as sensitivity (green) multiplied by sun ‘power’ (red). It is used to calculate the UV Index.
.

That diagram has a logarithmic scale so the green line is easier to draw. But a linear scale is much easier to understand.
So here is the ‘skin sensitivity’ in a linear diagram:

No danger of sunburn above 320 nm.

ggf31416 · 2019-02-21T19:29:25.000Z

From the effect on my photochromatic glasses, for a Convoy S2+ at 700mA at about 1 meter the effect is slower than direct sunlight in summer and has about the same speed as in a cloudy day. However note that photochromic glasses will darken from high intensity blue light as well, so they are not a precise indicator of UV output.

At less than 10cm they will turn dark instantly, if it was my eye I imagine it would be quite harmful. Never look directly into an UV led at short distance.

Lumencraft-Matt · 2021-10-06T21:42:47.000Z

I would be really interested to see how the Seoul CUN66A1*G* compares on this chart vs the CUN66A1*B*

Verodin · 2022-02-11T21:40:35.000Z

Apologies for hijacking this thread but djozz, you seem to have tested a bunch of UV LEDs over the years (in multiple threads) and are thus possibly our resident expert

Have you ever seen this one? I’m trying to identify it, but no luck.

djozz · 2022-02-11T23:25:01.000Z

No I have not seen this one. It is the type that would be in the range of 365nm-400nm, the deep UV leds look different. The die is looking very much like the one that Luminus uses, including the precise dot array, but the package is not Luminus.

I’m not much in testing uv leds anymore, I even have a bunch leds in house (365nmm and 270nm) for ages that I never came round to testing. And I developed an improved configuration for testing uv leds more than a year ago that I have not used yet. Maybe if life slows down in the future I dive into them again.

Verodin · 2022-02-12T10:56:28.000Z

Was worth a try to ask, thanks. It just peeked my curiosity since the die looks like Luminus as you pointed out. But the package looks very much like a Seoul Viosys CA3535_Flat. Guess this one will remain a mystery for the time being.