UV LED impressions

Tythagoras

Newly Enlightened
Joined
May 29, 2005
Messages
11
Location
Eureka, CA
Xenopus was kind enough to send me some UV LEDs and I have had a chance to test some of them. The 395nm LED fell out of the envelope before it got to me, so I didn't get to see how it performed.

I used my Inova X1 as the host for my testing. I used it's internal boost circuitry unmodified, but I didn't have a way to measure the LED current while it was in operation.

The FoxUV is not very impressive at all. I expected a lot more from what I was reading here on CPF. It emits very little visible light, but the UV it emits doesn't cause things to fluoresce more brightly than the others tested. It seemed very dim in both visible and UV, but it could be due to the X1's driver circuit not providing the current required. I wasn't able to find anything that it would fluoresce that didn't fluoresce with a longer wavelength. I didn't have a $100 bill to test, though. I really want to make a pocket bill verifier, since I occasionally have to deal with counterfeit bills and ID cards. I may get some more of these just because I can. I can't find a supplier for the Nichia 365nm LED, though I wish I could.

A secondary problem of the FoxUV is that the glass lens of the X-1 cuts the output considerably, so I ran it without the lens temporarily, but that compromises the waterproofing of the design, so it was for testing only.

Xenopus also sent me an LED labeled 385nm. I am keeping this one in my X1. It causes things to fluoresce brightly, and doesn't seem to be affected negatively by the lens of the X1.

I still can't detect dog urine, but US$5 and $20 notes show up well, and the UV reactive fibers in the paper of checks, certificates, and my amateur radio license shows up clearly. It seems to work fine to check ID cards and credit cards. Some mold and some food residue show up nicely also.

I can see why Xenopus uses the 385nm LEDs in many of his lights. They are bright and will fluoresce a wide variety of materials.

I am planning on modifying an Xnova to ultraviolet if I can get some UV LEDs. I would like to know if anyone knows who might sell the Nichia 365nm in small quantities. Otherwise I may have to pester Xenopus into selling me more of those 385nm units.
 

IsaacHayes

Flashlight Enthusiast
Joined
Jan 30, 2003
Messages
5,876
Location
Missouri
Xenopus should have some too. Litemania has some Nichia 5mm metal can ones, but they are cree I believe (not a bad thing).
 

cratz2

Flashlight Enthusiast
Joined
Apr 6, 2003
Messages
3,947
Location
Central IN
Yeah, not all UV LEDs are created equal!

Still the best ones I've ever had were some 375nm LEDs and they put out very little visible light, but makes some things flouresce like crazy! Soap around the washing machine and on the laundry detergent bottle itself, an orange had from 10 feet. I'd love to mod an XNova with some of these.
 

Sean

Flashlight Enthusiast
Joined
Dec 11, 2001
Messages
2,971
Location
IL, near St. Louis MO
Tythagoras said:
Xenopus was kind enough to send me some UV LEDs and I have had a chance to test some of them. The 395nm LED fell out of the envelope before it got to me, so I didn't get to see how it performed.

Same thing happened to me. Except it was the 365nm that is MIA.
 
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