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UV LEDs

UV LEDs

(OP)
I'm not sure if this is the best place for this question, but couldn't find a more suitable fit.

I was hoping someone could help me clairify the differences between ultraviolet wavelengths?  In my Google searches, I have run across several different terms and wavelengths.  My understanding is the following are interchangable:

UVA or Long Wave UV (345-400nM)
UVB or Medium Wave UV (280-315nM)
UVC or Short Wave UV (200-280nM)

Once I get my terminology straightened out, I'll be looking for suppliers for "UVC" LEDs (if they exist).

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

RE: UV LEDs

You're mad!


I think you are going to have problems finding that in a LED at this time.  What kind of use are you up to this time? :)

The reason I ask is because you may need to use a crystal frequency shifter.  This could allow you to use a more common LED to drive it - But this could have dimensional limitations.

Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com

RE: UV LEDs

You may have some difficulty finding shortwave UV LEDs... longwave no problem, but shortwave is a tall order.  Here's an article form Sandia National Labs on being able to output 1.4mW (yes, that's milli) from a shortwave LED:
http://www.sandia.gov/news-center/news-releases/2003/elect-semi-sensors/uvleds.html

You'll also find a number of patents on them, but no real substance to the work.

Are you sure you need shortwave?  Give us an idea of the application and we can probably help you sort it out.

Dan - Owner
http://www.Hi-TecDesigns.com

RE: UV LEDs

(OP)
I'm considering designing a hand-held UV light with selectable Short/Medium/Long wave UV lights for fluorescent mineral and gem collecting/inspection.  Client does not desire existing 3-wave UV lights due to battery packs, weight, and size.  I know long wave LEDs are out there, but was unsure of medium and short.

I was trying to define nM ranges to see what the cost point would be for LEDs.  Customer would like a selling point under $40, and I am envisioning a flashlight like device, with 2-3 rechargeable AA batteries.  Seems similar devices are only long wave, and there's probably a reason for it.

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

RE: UV LEDs

hmmm..  Tough one there.. I presume that the source would only need to be on short periods.  Perhaps an incandescent or fluorescent source could work.  If it needs to be on a long time then it might need to be plugged in. ??  Just a thought.

Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com

RE: UV LEDs

(OP)
I was pretty sure it was just a pipedream for now.  Maybe in another 2-5yrs.  Thanks fo rall the input.

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

RE: UV LEDs

(OP)
I have not read it, even though I am a fan of Niven.  Its on my "1 Million Things to do Before I Die" list though. ;)

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

RE: UV LEDs

Hi Mango:
Offer him to design an UV-lamp with hand-driven generator.
( look Mom -- no battery ! )


----------------------------
Please read FAQ240-1032
My WEB: <http://geocities.com/nbucska/>

RE: UV LEDs

Thanks bucs, I'll need a new book in about 5 days.  I'll look for it at Borders.

Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com

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