4 more 365nm UV-leds tested

Thanks for the input, guys, really appreciated. Hadn’t seen your thread, Scientist, I like the glass cutting part. :nerd_face:

So less modes then.
I think I still have a 5A LD-1 lying somewhere, although I never rigged one for momentary use. I’m much more confident when the driver limits the current, so I don’t have to worry which cell I use. A 25R can deliver lots of juice…

I ordered the C8F host (and 2 spare MCPCBs), so I don’t have their driver. But this host really has grown on me:
3p-setup, DTP copper MCPCB and really flat surface in the head, reflector and MCPCB are tightened with a screw from the inside, lots of room for the driver, an easy to press sideswitch with a crisp click, driver retention ring, enough space for a protected cell, squared threads on both sides of the tube, anodized threads at the tail for lockout, flawless anodizing. And the spare MCPCBs came with a foil on the copper side for protection.
Sofirn did a lot of things very, very well on this one. :+1:

Let’s get cooking :partying_face:

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Looks great. I will be looking forward to seeing your results. Yeah, djozz took care of us with his group buy for filters. I couldn’t find anything when I looked around so resorted to rolling my own.

Reflowing went well and I did find my spare LD-1.

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All three lighting up evenly (this is with a cell at 3.25V resting).

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Installing into the C8F host was easy. With the LD-1 I went for 3 mode and de-soldered moon.

I’m just not sure the beam is looking as it is supposed to look.
The center is yellow, then some dark area, followed by a blue corona.
Did I already wreck the LEDs or is that ok that way?
(Still without djozz’s filter)

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Edit: The center seems to be the ‘good’ part with the most UV radiation. It’s really fun to play with. Now I’m curious which effect the filter will have.

I think the 365nm light exits the dome of the led quite differently as the visible light (the refraction is fairly dependent on wavelength and 365nm is quite far from the average visible light) , resulting in a different focal point, this becomes more apparent with smooth reflectors.

Just this afternoon I made a C8 with the same led (but just one) and using a standard center piece the hotspot was pretty ugly. It improved when I sanded the centerpiece thinner, just like when using domeless leds compared to leds with dome.

This is pretty interesting, I will look into it a bit more precise this evening.

That’s what mine looked like too. I agree with djozz that the visible light makes that yellow center. The ZWB filter cleans it up nicely. I notice the “petals” around the edge of the spill due to the three reflectors more than with a single emitter. It is fun, isn’t it!

I just did a quick check and after all the visible light does not seem to focus extremely different from the UV after all.

Btw, indeed a 365nm thrower is more fun than I thought, you achieve so much more brightness, while not having to get close to anything, that makes checking a room for fluorescence much quicker.

Here’s the beam of the 365nm C8 with Seoul Viosys led and ZWB2 filter, from 2.5 meter. The unevenness of the hotspot is the plaster on the wall showing uneven fluorescence. And a nightstand (not mine :innocent: ) with playmobil dragon to get an idea of what you get.

I got your black glass today, just ordered the triple Seoul emitters from Kaidomain, will figure out what to do with everything later… :wink:

Thanks for sparking this up Jos, neat ideas and nice testing. :+1:

Decided that a vacant C8 host was going to be a UV thrower but I ran into some troubles with the beamshot(s). Because White Walls Won’t Work With UV. Then I remembered djozz showed us to use the illumination of UV light on white paper. Of course I did not have a large enough piece of white paper. But I had a piece of shelf paper that was white enough to do the trick.

On the left you see the hotspot of the C8 at 1.8m (6ft). On the right you see the result of the latest model UV Convoy S2+ at 1.8m.

Here you find what I did to get the left beam from a third generation LG 3535 UV-emitter I bought from Simon (Convoy).

Really nice,that hot spot is mesmerizing.

Hi @djozz, did you ever test 5mm uv leds? I think I remember you did but cant find the thread.

I am eyeing a coast tx10 as a host for 3 or 4 wavelengths which can be individually switched for any desired combination.

Seoul Viosys Z5 CUN66A1B

Wonderful post! As a UV flashlight collector/user I will need to spend a lot more time here and on the related post(s). I’ve gotten distracted/frustrated with BLF and CPF because the UV stuff is mixed in with all sorts of tighty-whiteys without an easy way for me to spend a few hours reading just about UV without ending up buying more whiteys.

My first question came while quickly scanning through the post (and I did word-search the comments for ‘Vishay’ to see if I’m not that the first to wonder):

- Would putting a Vishay in a zoomie be passable stand-in for a 365nm laser pointer? I use 405nm laser pointers quite a bit, but would really like a small dot 365nm. I have two or three cheap 365nm zoomies that so me a crude sort of small-spot by zooming until I see the shape of the LED. It seems like it might be even more useful with a tiny LED like this one.

Alan

It could be a good idea. I did not measure it but it seems like the luminance of the die is the highest of them all. That small die did not work in a OP-reflector flashlight but a zoomie should work. Only problem: most plastic zoomie lenses are very poor 365nm trensmitters, you should find one with a glass lens.

On the road i3, a tiny one with a glass lens, still available on gearbrst

Hmmm … I came across something about glass lenses and UV the other day, determined that my Streamlight Night Com had better UV behavior without the lens than with it (but not enough better to work on finding a solution), and decided to go back and get a watch case opener I looked at the other day so I can check some other flashlights.

Soooo … I hauled out my generic/ultrafire/mystery 365nm zoomies, and at least two have good 365nm behavior. I’m pretty sure these are glass. The other may not be, based on its poor behavior and laser checking it.

If I can figure out how to take the front ends of those things apart (Googling shall be my guide), I can play around with them and see if it might be worth getting an emitter for one of them.

I did occasional-to-frequent technical soldering from the mid-1960s to the mid-1990s. It may be a recoverable skill. :disguised_face:

Fun.

Thank you.

Nooooooooooooooooooooooooooooo …

You just added another whitey to my shopping list.

[sigh]

Two, if it turns out that is good glass (& coating? probably uncoated?) for 365nm.

But thank you for the heads up. I’ve now got the GearBest and FastTech listings bookmarked, and the On The Road store on AliExpress saved to study later - it looks like the i3 isn’t in their current line.

awesome work, thanks! :slight_smile:

a couple of questions:

from the graph the two nichias seem way less powerful than the LG… does that mean that, for example, the Nichia S2+ is better than the cheaper LG S2 in terms of light quality, but not in terms of output?

2) I may need several uv leds for a project… is there any decent cheap uv led around? are these any good for example?

3535 3w EPILEDS led:

UV LED:365-370nm

DC Forward Voltage:3.2V~4V

Forward Current: 350-1000mA

heat resistance:9/W

Luminous Power:700-1200mW

https://www.aliexpress.com/store/product/3W-3535-High-Power-LED-UV-Light-Chip-365nm-Emitter-Diode-Ultra-Violet-DIY-With-8/815938_32763138896.html?spm=a2g0y.12010615.0.0.28f82127z91Rpr

and in general this shop has plenty of cheap UV leds of various kinds:
https://www.aliexpress.com/store/815938/search?spm=2114.12010615.0.0.2d4d5a92e97FYE&SearchText=uv%20led&origin=y&SortType=price_asc

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Okay, I found my 365nm SK68 doubtfires/fauxfires, disassembled them without difficulty, tested all the (resin? certainly not glass, not what I think of as “plastic”) lenses, and none of them (including from white LED counterparts) diminishes the 365nm illumination significantly, so that’s a go.

I put a 20.5mm 365nm filter in one, since it fit and I had bought extra (perhaps for this purpose) when I got one for my Convoy s2+ UV a few years ago. Happy times. :disguised_face:

Also got a watch case tool, so am preparing to move forward.