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:
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.
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.
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
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.
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?
Sunlight is much worse, 365nm UV has hardly any effect. The problem is your eyes.
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.
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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.
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.
I would be really interested to see how the Seoul CUN66A1*G* compares on this chart vs the CUN66A1*B*
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.
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.
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.