I need a source of UV light for some Pglo plasmid experiments I am doing. Anyone know of a source for UV Leds. I googled, but just got some nonsense.

 

I Googled ultraviolet leds and got quite a few hits that look legitimate, even a UV flashlight. Depends, of course, how deep into the UV you need to go.

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Carl

 

oops, your right. I think my mistake was using a search on UV rather than spelling the word ultraviolet leds.

Thanks

 

From one of the data sheets I found for UV diodes, I was interested to note the Vf was 3.5 v. There seems to be a trend with LED's, shorter wavelength = higher Vf. Curious as to why, I pulled out one of my chem books and found the formulas. E= hv and v=c/lambda, where E = energy of photon, h is Planck constant 6.626 x 10^-34, v = frequency of light, c= speed of light, and lambda is wavelength in nanometers. So as we can conclude from the formula that shorter wavelength = more energy. Looking at a spectrum chart http://www.antonine-education.co.uk/...m_spectrum.jpg

Red leds are longest wavelength, hence lowest Vf or energy, while UV light is shortest wavelength and requires more energy or Vf.
I dunno, I just thought it was interesting and thought I would share something that I never thought about before.
So we can make a Rule of thumb here (As if thumbs did not have enough rules already) Lowest on spectrum chart, lowest Vf.

 

Any specific Wavelength for the UV LEDs?

-BaC

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I think that is around 400nm, give or take 5

 

I asked for that...lol

All I was thinking is the 390-395s they have as UV LEDs..Blacklight aka Near-UV. Just be sure to read the fine prints.lol damned that ebay!

-BaC

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Ebay are a good source for UV LEDs - I've seen them in the 395-405nm range for around $10 per 50

 

I found these guys.
LEDtronics Ultraviolet LEDs: UV Discretes; SMD, 3mm, 5mm, High-Flux

 

It is all good I appreciate you taking the time... Just when you thought the world stunk, you meet so many nice people on these forums

 

My Favorite ebay LED guys:

eBay Store - HKJE Led Lamp Center: New LED Product From Factory, 0603,0805,1206 SMD SMT LEDs

They are very nice, like I said takes sometime from Asia..
-BaC

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Will check it out. Thanks

 

Hi Mikebits,

Seoul Semiconductor manufactures UV-LEDs with a wave length of 340nm. There are two different types, the S8D34, a dome type SMD-device with wide angle emission of +/- 40deg and the T9F34, a flat faced wired device with a narrow angle of +/-5deg.

Both have a foreward voltage of 5.5V to 7.5V.

At this wavelength special care has to be taken not to look into their beam with the eyes unprotected, because they can cause severe and unrepairable damage to the eye.

The disadvantage of both: They cost US$ 55 per piece at a minimum order of 100.

Depending on the application 400nm would probably not be the best selection. Their light emission is approximately 95% blue and the rest is UV.

Boncuk

 

400nm is neared than violet than UV and 405nm is pretty much far violet rather than UV. You'll be able to see both wavelengths pretty well and will appear deep violet.

Both wavelengths will produce some black light effect, even 450nm blue light will to some degree but are you sure that it's high enough energy to excite the phsphor you want?

You might be better off using a black light blue fluroscent tube, CCT or CFT; these give peak at around 360nm to 380nm and are much more efficent UV emitters than LEDs and probaly work out cheaper per watt of power too.

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Mine came from superbrightleds.com.

I've been using their 20mW 400nm model in a custom ultraviolet flashlight for almost a year now. I also have the 405nm version and both have the same basic effect as a UV party lamp (just scaled down, of course). There's noticeably a lot more purple in the hue than a party lamp, but the effect is still there. But, they have spectral plots for all their products on the site.

I don't know how much illumination you need, but they also have 200mW version in a large LED assembly called an XLamp. The XLamp is basically the high-powered LED, plus the required heatsink, plus an optional parabolic reflector like they use in mini flashlights.

In fact, all their LEDs are really good. They have a lot of LED devices you can't find anywhere else, they carry the unusual hues like UV, violet and warm white, plus they shipped everything to me within 3 business days.

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