Best brand UV led for project?

i have read a bunch of threads pertainiing to UV leds, as well as Craig's info on them.

my wife and i were married at fort gratiot lighthouse in port huron michigan. as a wedding gift, my brother built a 4 foot tall lighthouse. it had a flourescent bulb in it.

wellll...i have over the winter changed it to a cyan 5w star, hooked to a pulser: it blinks on quickly, then dims to off over a few seconds. i was able to tune it to flash once every 15 seconds--just like the real ft gratiot lighthouse (the real light color is almost identical to the cyan luxeon). it will run off a 6v 100ma dc adapter--i am surprised at how well it works!!!

oops...went off topic there.

i will have the lighthouse up on a pedestal, surrounded by a "sea" of flowers. there will be a boat/ship of some sort floating in this sea.
this dislpay will be about 70 ft from my back door.

i want to GENTLY illuminate the display--the lighthouse, ship and sea of flowers.
i thought it would be fantastic to use some UV leds. one would be at the base of the lighthouse pointing up to make it glow (it is white and blue). one or two others would be hidden, and illuminate the ship and sea of flowers: i will try to choose flowers that glow nicely.

now for the question: what UV leds might be best for this purpose? 3 choices so far, with all the info i have:

LED supply --has some 400nm 12 mw at 20ma.
all electronics --395nm, ?mcd, ?mw
superbrite --405nm 2000mcd 80 mw

all are pretty inexpensive at around $2 each.

which would you get, and why?

Bob<--probably making a mountain out of a molehill, but i really want this to turn out nice.

Try the seller BESTHONGKONG on Ebay....cheap and very nice 5 mm 395nm LEDs with a 15mw Cree chip (one of the best!)

It depends on what you are trying to light up, some materials will glow wonderfully under 395-405, and some materials will "ignore" the light entirely

For example, some of the UV-Stripes on the new bills will show great under 395-405, but others will barely glow - and work better under 375nm

You might need to experiment some LEDs and material

Since it sounds like you're going for the 'glow' effect from the UV, rather than wanting the actual purple light itself, I'd say you probably want to go for the shortest wavelength (lowest nm) uv LED you can find. Those generally put off less visible light, which means you're getting more high energy light that will be converted by whatever materials you're trying to fluoresce.

The cheap besthongkong leds use a Taiwanese chip, not the Cree chip.

I'm a little bit uncomfortable with this project. UV lights are covered with safety stickers for a good reason. UV light is bad for your eyes. It's one thing to look at a bug or something with a UV led in the daytime now and then, but looking at the lighthouse for long periods at night (when your pupils are fully dilated) doesn't sound wise. I'd say stick with visible light.

If you can wait until the end of the year, Nichia apparently has a new UV LED with a peak wavelength at 365nm which is about midway into the longwave UV spectrum - it should light up lots of fluorescent materials.

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bricksie said:
If you can wait until the end of the year, Nichia apparently has a new UV LED with a peak wavelength at 365nm which is about midway into the longwave UV spectrum - it should light up lots of fluorescent materials.

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Is this LED available for purchase anywhere yet?

>I'm a little bit uncomfortable with this project. UV lights are covered with safety stickers for a good reason.

Consider the distance and the intensity he wishes to have..

>this dislpay will be about 70 ft from my back door. i want to GENTLY illuminate the display

I imagine it being any worse than a bug zapper in his back yard. Speaking of which, this thing is going be an insect magnet.

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duffahtolla said:
>I'm a little bit uncomfortable with this project. UV lights are covered with safety stickers for a good reason.

Consider the distance and the intensity he wishes to have..

>this dislpay will be about 70 ft from my back door. i want to GENTLY illuminate the display

I imagine it being any worse than a bug zapper in his back yard. Speaking of which, this thing is going be an insect magnet.

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well, i might still use blue or yellow, or even plain white.

bug magnet? i guess it would keep them away from the deck!

i will certainly have to experiment a bit--but at least it wont be expensive.

thanks for all the suggestions!

Bob

PhotonWrangler,
According to Nichia's web site, this new LED isn't scheduled for mass release until December - I haven't heard of any other manufacturer that is mass-producing a UV LED of this peak wavelength so if you want one you may have to wait...

When I bought them, they were advertised as Cree chips...and they sure have one! Price was a bit higher though Cree has a single wire bond, the others (less powerfull ones) have a double bond wire.

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bricksie said:
PhotonWrangler,
According to Nichia's web site, this new LED isn't scheduled for mass release until December

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Dang. Thanks for the information anyway! Mebbe Santa will leave some in my stocking this Christmas /ubbthreads/images/graemlins/santa.gif