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What Can Be Done With Them?

R

Ron Hubbard

Jan 1, 1970
0
I found a bunch of ultraviolet LEDs at a surplus place and
bought them for a buck a piece; they seemed like a good buy at
the time. But I realized later that I really didn't have a
good practical purpose for them.

Does anyone have a suggestion for using UV LEDs?

Thanks
 
T

the Wiz

Jan 1, 1970
0
Ron Hubbard said:
I found a bunch of ultraviolet LEDs at a surplus place and
bought them for a buck a piece; they seemed like a good buy at
the time. But I realized later that I really didn't have a
good practical purpose for them.

Does anyone have a suggestion for using UV LEDs?

Thanks

Get some UV fluorescent chalk or paint and create some masterpieces of art, then
use the UV LEDs to illuminate them in a darkened room.

More about me: http://www.jecarter.com/
VB3/VB6/NSBasic Palm/C/PowerBasic source code: http://www.jecarter.com/programs.html
Drivers for Pablo graphics tablet and JamCam cameras: http://home.earthlink.net/~mwbt/
johnecarter at@at mindspring dot.dot com. Fix the obvious to reply by email.
 
G

Garrett Mace

Jan 1, 1970
0
Ron Hubbard said:
I found a bunch of ultraviolet LEDs at a surplus place and
bought them for a buck a piece; they seemed like a good buy at
the time. But I realized later that I really didn't have a
good practical purpose for them.

Does anyone have a suggestion for using UV LEDs?

Thanks

Make floater lights for your bike, rollerblades, kid's tricycle, the dog or
cat, and your mailbox.

Walk around house with an LED, resistor, and battery held together by your
fingers and Scotch tape, pointing it at various things and saying "Hmm, not
fluorescent" until someone else goes crazy.

Try to make a UV circuit-board lightbox until you realize that not only is
the wavelength too low, but milliwatts of power don't mean a very fast
exposure.

Try different highlighter markers until you find one that glows, scrawl your
name on a piece of paper and prop it up at work with a UV LED pointing at
it.

Get neon cables for your computer, gash a huge window in the side and light
it up. No reason necessary or possible.

Resell them on eBay with a four-page-long rant extolling their virtues in
large-sized multicolor fonts.

Set up an admission booth to your house and require all entering to have the
invisible UV stamp on their hand.

Use the LEDs to create a line-following robot that follows a UV ink line
invisible in normal light. Whoa...I think that was actually a serious
suggestion. Maybe now I have something to do with my OWN stock of UV LEDs
bought on impulse?
 
G

Garrett Mace

Jan 1, 1970
0
Try to make a UV circuit-board lightbox until you realize that not only is
the wavelength too low, but milliwatts of power don't mean a very fast
exposure.

I meant *too high* of course. Frequency too low.
 
J

John Fortier

Jan 1, 1970
0
Garrett Mace said:
I meant *too high* of course. Frequency too low.

Sew them to the insides of your long johns for a winter tan?

John
 
K

Keith R. Williams

Jan 1, 1970
0
Sew them to the insides of your long johns for a winter tan?

I was going to suggest temporary tattoos. Colors are a small
problem of pain, but...
 
M

Mark Haase

Jan 1, 1970
0
Motel room inspection lights.

That's actually a good idea. The OP could build a few enclosed units and
label them with some funny product name and sell them as novelty items.
 
G

Garrett Mace

Jan 1, 1970
0
Mark Haase said:
That's actually a good idea. The OP could build a few enclosed units and
label them with some funny product name and sell them as novelty item.

I think you need an LED further up into the UV spectrum than the ones I've
seen priced cheaply. Not that any definitive test data is available. I'm not
about to be the one to shout "hey it works!" and allow questions to brew in
people's minds.
 
C

Charles Jean

Jan 1, 1970
0
On Sat, 11 Oct 2003 20:29:36 -0400, Keith R. Williams

As you say, the wavelength is too high. Most fluorescent "stuff"
requires a wavelength lower than 280 nm, some down as far as 200, in
order to do much fluorescence. Pyrex and plastics are notorious for
actually "absorbing* this UV range. Anybody that works in this UV
range usually uses quartz, for its good UV transmission. I wonder if
these "UV" LEDs are encapsulated in either glass or plastic? The
lowest peak emission wavelengths I've seen have been about 375 nm, not
low enough for any dramatic UV effects.

The scorpions here in AZ fluoresce very nicely at night with a "black
light." I would like to have a little more range than one of these
LEDs can provide, however.

Hey, we've got infra-red to blue. Why not REAL UV? I feel like a
deprived child! Maybe we could start a petition to our legislative
bodies for relief.... No, never mind, I'm OK now.

I was going to suggest temporary tattoos. Colors are a small
problem of pain, but...

God invented. Newton, Maxwell and Einstein were just reverse
engineering.
 
D

Dr Engelbert Buxbaum

Jan 1, 1970
0
Charles said:
On Sat, 11 Oct 2003 20:29:36 -0400, Keith R. Williams

As you say, the wavelength is too high. Most fluorescent "stuff"
requires a wavelength lower than 280 nm, some down as far as 200, in
order to do much fluorescence.


Not so. Fluorescein for example gets excited at 490 nm. 400 nm will
probably work with those white fluorescent dyes contained in washing
powder. Also there are fluorescent marker pens to mark property, the
marking should be excited at this wavelength.

In some countries bank notes are marked with a fluorescent pattern that
can be excited at about 400 nm (to check for forgeries).

Postage stamps are sometimes printed on fluorescent paper (from some
German stamps there are both fluorescent and non-fluorescent versions,
with a huge difference in value).

Some minerals show fluorescence at relatively long wavelength.

If you have a microscope, 400 nm LEDs could be used to make UV
illumination to see the fluorescence of chlorophyll, and the
auto-fluorescence of some tissues (in particular after
formalin-fixation).
 
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