I am thinking about getting/building a good UV flashlight as an improvement over a crappy multiple 5mm LED flashlight for a friend, but I don't want to bother her with the handling and charging of LiIon rechargeables. After putting some thought into it, I see two options.
1. Get an Ultrafire WF-501A 1xCR123 P60 host and a UV Dropin from Manafont.
I assume I would have to replace the driver with a boost driver. Would any common driver work for a UV LED? I still have one of these flying around. A 1xCR123 light should be safe to handle for an inexperienced person, right? Not going boom when run down?
2. Get an AA flashlight as a modding host and replace the emitter with a UV LED
Are there any UV LEDs available on stars? Would they fit inside a standard reflector? Can you recommend a good modding host?
Which of these options would you prefer, or do you have a better idea? Any thoughts welcome!
A cheap host that’d work on three AAA batteries is the Costco three pack of flashlights. With a high power uv led, it may be a simple led and board swap.
Dereelight Javelin may work too, as a 2aa p60 host of sorts.
Or you could build/modify a low voltage drop in and use the 2xAA compatible Solarforce “L2r” (which isn’t the original L2r any more but works nonetheless).
If you want a cheap 17 mm driver for 2xAA, I have successfully used this (single mode, ~700 mA) :
My neighbor has a “Gem and Mineral Supply” store. She has had (since I met her as a child) a beautiful box with a small observation hole and three light bulbs behind a safety screen inside: a 100W White, a nm UV and a_nm UV ( IIRC they’re called “Long” and “Short” UV…) and the buttons to control them.
She places an assortment of various minerals on the black carpet on the bottom, seals the box and visitors to her shop can safely marvel at the wonders of Nature…
All I really remember from my childhood days with my Grandfather, going out “rockhounding” (amateur geology), is that BOTH frequencies (individually and together) are necessary to get the maximum effect.
Given that LEDs are so “monochromatic” (XM-L spray-&-pray color notwithstanding), My suggestion for a UV inspection light for a geologist (amateur or otherwise) would be to get a “multi-emitter” host and use at least two different frequency UV LEDs. Go with (e.g.) 4-LED host, use “UV High” (meaning frequency), “UV Low”, White and Red (to preserve night vision). Then all needs are met with one torch. I’d ask for a Momentary-ON switch and 4+ hours of runtime…
Elsewhere on this forum are tutorials for controlling individual emitters.
Assuming the User knows about the dangers of UV, IMNERHO that would be the optimum geologist’s torch.
The UltraFire WF 501c style hosts are reported to be useable as a 2x AA cell light if you cut a tube to length to hold the cells. That host is designed for 3x CR123a sized cells which happens to be the same length as 2xAA cells, just larger diameter. You would have to replace the driver on the LED Drop-In though.
Basically along the same lines of the discussion, get a Surefire 9P type (3xCR123) of host and get a low voltage drop in and use 2-AA’s. It is one of my favorite type of set-ups. There are many different ways to accomplish this using smaller hosts and extenders. But in short get a decent P60 host and use 2 rechargeable AA’s and a low voltage drop-in and you should be good to go.
Thanks for all your input! I just ordered the Solarforce host and the 380nm Taiwan dropin from manafont. I wasn't aware that there was an AA P60 host currently available from Solarforce, so I had to order that anyway
Dimbo, that was very interesting. I didn't realize that you need the whole UV spectrum to achieve the full effect. But as far as I know, at this time LEDs can only produce long wavelength UV. Even the real 365 nm UV LEDs are significantly more expensive than the widely available 380-400 nm ones, which have more visible purple UV light.
I guess if you want short wavelength UV, you are limited to specialised and very expensive UV lamps.
I'll see if the manafont dropin produces the desired effect, and if it doesn't, I still have a new Solarforce host
I posted the uk-ebay links thinking you were limited for buying choices, fyi.
I think the geologists use specific wavelengths for different minerals
I was mistaken thinking I could search for a “generic” rockhoumd uv light, Wrong, terms like “dichloric bandpass filter” told me I was in over my head.
Specific gems/minerals will tell the tale.
Another usage is checking the blanket & sheets in the motel room
ewww
It’s nice to see a wee nugget I’ve kept buried in the back of my head can still be useful.
Here’s another (perhaps less useful) one: North American Whitetail Deer (and I suspect many other prey species) see Very Well in the 400nm (deep twilight) range. If you hunt animals, whether you shoot with a camera or a gun, this should help. If you get the one you listed, shine it on your “outdoor clothes”. Any place that “pops”, “shines” or “glows” is a place that will scare the animals away.
And remember, just because we eat them there’s no reason to be mean to them!
Dim
(I’m assuming everyone here already knows scorpions fluoresce under UV…)
Depending on the purpose of the light and portability required, you might consider a flourescent tube light. They typically use 6 AA batteries and put out 8 Watts of power, compared to the 1 Watt CREE emitters from back 5 years or so. You can get one for about 10 bucks. It wont have as much directionality as the LED but the raw power makes it pretty useful. I have one and it works extremely well. Flourescents also are right at the 365nm output and are pretty efficient, compared to LEDS that are like 8% efficient at 365 nm, up to 20% at 380ish. (wiki)
An interesting mod that someone might want to attempt would be to figure out how to build an UV light using the Compact Flourescent bulbs that are available. If one could determine how to create an appropriate ballast or turn DC to AC using 18650s or whatever one could make say a 2x26650 light with a CFL on the end with a big reflector and get a good 12 Watts of power, plus strong directionality.
The solarforce host arrived today. It's a standard L2 with a 16340 extension, and it's great value for the price of just 15.99 USD. It just looks a bit awkward if you're used to standard P60 hosts.
The only drawback is, since this combo is marketed as suitable for 2xAA use, I expected it to include an adaptor sleeve to accommodate the batteries in the large tube, but it didn't. I just made a paper tube then.
I know the paper thingy looks flimsy, but I used a good amount of strong paper, rolled it very tight, and reinforced the edges with liquid superglue, so it's actually quite solid and should last a while.
