# UV Spot?



## SpectreTTM (Aug 22, 2005)

I wonder how easy it would be to replace all these LEDs'
With UV ones to make a great UV Spot light?

http://www.thingsyouneverknew.com/w...p?item_no=81870&source_code=JE500&entry=email


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## MansionHaunter (Sep 20, 2006)

Probably not very easy, since the LEDs are most likely soldered down pretty close on a circular circuit board. I'm sure it could be done if you had the time and patience. 

And then you'd have to change out the dropping resistor to something a lot smaller, since the forward voltage drop of the UV LEDs is anywhere between 3.9 and 4.5 Volts -- and with 3 AA batteries you've only got 4.5 Volts to work with. Forward drops on white LEDs are around 3.2 to 3.8 Volts.

But making a spotlight out of a tight grouping of UV LEDs is certainly possible without too much trouble.


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## MansionHaunter (Sep 20, 2006)

How about this: a link to a UV flashlight. Ba-da-bing.

http://www.theledlight.com/uv_flashlights.html


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## SpectreTTM (Aug 22, 2005)

MansionHaunter said:


> How about this: a link to a UV flashlight. Ba-da-bing.
> 
> http://www.theledlight.com/uv_flashlights.html


I suppose but when you are comparing the costs of a $19 flash light + some cheap UV LEDS from e-bay vs $500 for this model XeLED-32UV-R-375 I just might be worth the work.

I think I might pick up a couple to see what I can do. When I have time after Halloween 

Thanks for the link and the input


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## joshschaf (Jan 9, 2006)

*cheap AC 110 18 LED spots*

I have been using these and so far so great. Thought I would share my secret, cheaper than most and only a bit more than building yourself.

http://cgi.ebay.com/ws/eBayISAPI.dl...60011842842&rd=1&sspagename=STRK:MEWN:IT&rd=1

See the other listings for UV


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## SpectreTTM (Aug 22, 2005)

joshschaf said:


> I have been using these and so far so great. Thought I would share my secret, cheaper than most and only a bit more than building yourself.
> 
> http://cgi.ebay.com/ws/eBayISAPI.dl...60011842842&rd=1&sspagename=STRK:MEWN:IT&rd=1
> 
> See the other listings for UV


Have you used the UV ones? 
If so how doe they compare to a Tube?
How far is there throw?

Thanks


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## heresjohnny (Feb 15, 2006)

Hey SpectreTMM, I have 50 UV LEDs from BestHongKong on the way, total cost $9.99. They didn't specify a brightness other than 'intensly bright', however they are directional (20 degrees) and I plan on building a few UV spots with them. I will post results when I can. 

The AC 110 LED spots have a stated intensity of 10k mcd, if that is for the whole spot that is not very bright. I have seen 10mm LEDs that are 60K mcd.


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## slimy (Jul 12, 2006)

I just ordered the 4 pack bulb package from joshschaf post. I will let you know about the brightness. 

Did not order UV light, just happy for the link. Sorry for hijacking the thread.


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## SpectreTTM (Aug 22, 2005)

heresjohnny said:


> Hey SpectreTMM, I have 50 UV LEDs from BestHongKong on the way, total cost $9.99. They didn't specify a brightness other than 'intensly bright', however they are directional (20 degrees) and I plan on building a few UV spots with them. I will post results when I can.
> 
> The AC 110 LED spots have a stated intensity of 10k mcd, if that is for the whole spot that is not very bright. I have seen 10mm LEDs that are 60K mcd.


Hey HJ,

Thanks for the info. I ordered a boat load of the UV LED's From Hong Kong as well last yr.
I haven't had a chance to use them yet. That is why I was asking about the flash light at 
the top of the thread. Please let me know your progress.

Thanks for the info.



slimy said:


> I just ordered the 4 pack bulb package from joshschaf post. I will let
> you know about the brightness.
> 
> Did not order UV light, just happy for the link. Sorry for hijacking the thread.


No Prob Slimey,
To me you are still on topic and I welcome the advice and input. After all 
isn't that what this forum is about sharing ideas 

I'd still like to know If anyone has the UV versions of those spots. I really like the concept.
110 is so much easier to work with.

I was toying with the idea of the low voltage lights like Malibu and using a rectifier to convert
the low voltage AC to low voltage DC to run LED Spots.


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## joshschaf (Jan 9, 2006)

The throw seems to be around 6-8ft. The pic I have is of the green, but both stones are set the same distance from the fence. You can see the UV one on the left side of the pic.


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## heresjohnny (Feb 15, 2006)

SpectreTTM said:


> Hey HJ,
> 
> Thanks for the info. I ordered a boat load of the UV LED's From Hong Kong as well last yr.
> I haven't had a chance to use them yet. That is why I was asking about the flash light at
> ...


LEDs came in today, prototyped a quick spot with 5 LEDs, and I am happy with the effect! I'm gonna try and snap some comparison pics tomorrow night with the FCG. So a $9 bag of 50 LEDs, with $2.50 in 9 volt batery clips will give me 10 small LED spots.


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## heresjohnny (Feb 15, 2006)

Did an experiment with the UV LED spotlight I built using 5 5mm <395mm LEDs I bought on ebay, 50 for $9.99. Comparing to an 18" blacklight on the FCG he LED spot didn't light up the ghost nearly as much as the 18" light (big suprise).
















What I did find suprising is that from about 3 feet with the LED spot, a bottle of UV reactive paint glowed as much as it did using the 18" light from the same distance. In fact the only way you can really tell the spot in the photos is that the left side of the table is dark in the LED spot light photo (the LED spots are very directional).

















In conclusion I think the LED spots (with 5 LEDs) will work great for isolated displays using black light reactive stuff.


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