Mod Cometa for 365nm UV?

Would it be worthwhile to mod a Cometa into a 365nm light? One day when I get around to starting my first mod, I think this would be my choice of interest while learning the intricacies of soldering. My confidence is building the more posts I read about it :THUMBS-UP:

Just in general, if anyone has an educated opinion about the potential of the Cometa becoming a strong nighttime UV search light, I would welcome your thoughts. Since I know nothing about what is needed, such as the optimum emitter or the cost of one, or what else is needed for the build, or if any existing parts can be reused, I am researching the topic. Also it gives me a major challenge while salvaging a Cometa.

I have no information to go on at this time and I really appreciate hearing any sound-feedback.

Also if it is a worthwhile mod then maybe a couple more questions will be ok: :???:

Guesstimate of the “high-side” for total dollars of new parts to do the project, minus the cost of the Cometa.

Would 2 batteries be an option or is there no benefit? (other than run-time?)

Are UV lights only on/off or is it possible to have a couple modes?

Would a maxxed modded Cometa 365nm light get hot if used for maybe 30 or 60 minutes? Nighttime treasure searching can take some time.

Thanks for sharing your experience and thoughts.

It would certainly project a UV beam a long distance. Can you describe more about how you would be using the light?

I recently purchased this UV LED. I believe int-outdoors has the same LED. I think djozz tested this LED and it is decent. There is a more expensive one by ledengine that performs better, but it is around $40 I believe. Nichia UV LEDs are also supposed to be very good, but I don’t know where to get it.

The one I got is rated for 700mA. So for the driver you would want a linear driver like the qlite from mtnelectronics, but with only 2 or 3 7135 chips. With this small current it will not get very hot. You can have different modes; check out the qlite page on mtnelectronics. It would be simpler to just use one cell; to use two cells, you would need a buck driver. Total cost would only be ~$15 for the LED and driver.

I built my UV LED into an eagle eye X6 with the purpose of finding fluorescent disc golf discs at night. I have not used it for this yet.

Main use would be along streams thru valleys with occasional scanning of hill sides.

Would you care to guess in feet or yards about how far a tight beam my reach out, on dark nights of course. I think that is what I am most curious about, is it going to cover larger areas with fewer unnecessary steps :innocent: A comparison may be my existing light reaches 12 feet ahead of me, and the Cometa “may” reach 35 + feet? Of course it is just speculation but maybe it will reach 60 feet, which would be superb!

I will check out mtnelectronics and begin researching. Thanks

It depends on what you are shining on. What is your current light and what sort of UV fluorescent treasure are you looking for? I don’t think I can give a good estimate of the useful distance, but I think the cometa is a good choice for what you want and you will probably be pleased with the result.

Also you’ll want to check what the lens is made of and whether that material
a) transmits UV, or
b) glows in the dark when exposed to UV

I’m running the “Intl-Outdoor” UV led in a Convoy S2+ on a Nanjg AK-47K 3*7135 driver without problems.
Don’t know if it is identical to the led you are interested in.
Due to the rather high Vf it won’t put out the expected 1.05A, but rather a decent 0.9A. With a regular 4.2 Li-Ion battery.
In the bigger Cometa, with more mass and hopefully more potential to absorp the heat, that should not lead to problems.

The biggest drawback is the excess of visible light that is NOT 365-370nm. And there is lots of it with this led.
You won’t enjoy playing with an UV light unless you block that unwanted part of the output with a ZWB2 filter.
These are quite available in the 20mm version that fits the Convoy S-line, but for a Cometa? (mucho $$:money_mouth_face:
Or you could buy a (more expensive) UV-led that has a lower percentage of visible light that masks the effect of UV light.

Djozz has published a lot of threads on UV leds and their collateral challenges.

Developements in 365nm UVleds have been fast the last two years, the intl-outdoor led has become a relatively weak one.

The visible light issue that Henk mentioned is indeed something serious, but if you would like to spend some money on it and are adventurous, you can try a B+W Schneider UG1 filter on ebay (bit over 70 dollars). It seems to have the correct size for the Z1, but you have to find a way to squeeze it in. Bur perhaps easier is to use a Nichia 276A U365, even without filter it has only limited visible light output.

The Z1 has a glass lens so the transparancy for 365nm radiation probably is good.

But for a suitable led, perhaps hold your breath, I have a quite modern LG 365nm led on order, it is on aliexpress now, that I will be testing. I expect it to have a good output and hope for not too much visible light, and the 55degrees beam angle ( it has a weird dome!) makes that led especially suitable for aspheric lens flashlights.

All 365nm leds consume only a moderate amount of power (current is under 1A), the Z1 handles that effortlessly.