# New Feit UV LED bulb



## PhotonWrangler

I spotted a new UV LED bulb at the "orange" DIY store tonight so I picked one up.

The bulb is rated at 9w and has an array of 26 SMT LEDs under a semi-transparent plastic dome. I fired it up and found that it appears to have a shorter wavelength than the standard purple NUV LEDs, which is good. However the plastic dome seems to fluoresce a little bit, slightly reducing the contrast of the UV effect, so I'm considering removing it. 

Not a bad little bulb for $15. It will come in handy for Halloween, and I can probably also use it as a diazo exposure lamp for my screen printing setup.

**Update**

I aimed another UV lamp into the globe on this bulb to see what is fluorescing, and it's not the globe; it's the white plastic bodies of the UV LEDs themselves.


----------



## Alaric Darconville

PhotonWrangler said:


> I spotted a new UV LED bulb at the "orange" DIY store tonight so I picked one up.


The "blue" DIY store in my town has dropped *some* of the Feit range, and have picked up Kichler for "antique-style" LED bulbs, but I digress.

I wonder if a CFL "black light" would still be the party funtime winner. Kindof a shame that the plastic itself is fluorescing; I wonder if that could be mitigated with a black Magic Marker.


----------



## PhotonWrangler

Alaric Darconville said:


> The "blue" DIY store in my town has dropped *some* of the Feit range, and have picked up Kichler for "antique-style" LED bulbs, but I digress.
> 
> I wonder if a CFL "black light" would still be the party funtime winner. Kindof a shame that the plastic itself is fluorescing; I wonder if that could be mitigated with a black Magic Marker.



I am considering taking a black magic marker to those LED cases. Can't believe a manufacturer would do that.

**Edit**

I just compared the useful UV brightness of this bulb to a 7w biaxial UV fluorescent lamp, and the LED bulb is subjectively brighter.

**Another update**

I've purchased a Sunlite brand UV LED bulb for comparison purposes. The Sunlite A19/LED/2W/BLB has a single UV LED in the center under a clear dome, and it advertises as being a true 365nm LED. So I dug out my Woods Glass filter and placed it in front of this LED and sure enough the UV energy passed right through with little attenuation, while all of the visible light was blocked. Nice.

Then I placed the Woods glass filter in front of the Feit LED and virtually nothing passed through, no visible light but also no fluorescence. This confirms that the Feit bulb is using a much longer wavelength. Having said that, the Feit bulb does produce much more fluorescence (without the filter in place) than the Sunlite bulb, at the expense of a little more visible light. 

Right now it looks like my ideal LED blacklight will be one that uses multiple 365nm chips with a Woods glass filter in front of it.

** Yet another update**

I bought a second Feit bulb at the same store, and while the packaging is the same, the bulb is different. This one has heat sink fins around the base and a narrower LED baseplate, but otherwise the same ratings and the same brightness. I've seen both styles of bulb online under different brand names.


----------



## PhotonWrangler

Now I'm on a mission to quantify UV wavelengths from various LED sources. I can't use one of those inexpensive diffraction grating spectrometers because it's UV, and I can't just eyeball it either. This leaves me with the choice of purchasing known specific wavelength UV LEDs (365nm through 395nm) and finding fluorescent materials that react to those specific wavelengths to provide indicators for measuring unknown sources against.

Has anyone else undertaken this type of project before?


----------



## Lexel

You can use documents and money to determine UV
there are marks only visible below 370nm

Convoy S2+ with nichia emitter without filter









and zwb2 filter


----------



## PhotonWrangler

Thank you Lexel. This is the kind of information I'm looking for. :thumbsup:

BTW I've just learned that Canadian Passports look absolutely psychedelic under UV light. Multiple colors of UV inks.

** Update **

I have some 390nm LEDs that (barely) fluoresce the green strip in a U.S. $20 bill, but the Feit bulb doesn't fluoresce it at all. This suggests that the Feit bulb is 395nm or longer in wavelength. Now we're getting somewhere!


----------



## PhotonWrangler

More UV madness in search of the perfect 120v UV bulb - 

I bought a CroLED 365nm UV LED lamp on Amazon, model HZT-1101B-1130B. This has an Edison base and is similar in size to the Feit bulb. It claims true 365nm from it's array of LEDs.

I screwed it into a fixture, turned it on, saw the familiar purplish glow, but NO fluoresence - absolutely nothing! My first thought was that the LEDs weren't really 365nm. 

I removed it from the fixture and shined a 390nm keychain NUV light through the plastic dome to confirm that it could pass that wavelength, and it did. Then I aimed a true 365nm UV flashlight through the plastic dome, and... nothing. They designed a UV light with 365nm LEDs with a plastic dome that blocks 365nm output! Argh.


----------



## Alaric Darconville

PhotonWrangler said:


> They designed a UV light with 365nm LEDs with a plastic dome that blocks 365nm output! Argh.


Time to write a review on amazon!


----------



## PhotonWrangler

Alaric Darconville said:


> Time to write a review on amazon!



Already done. Hopefully this info gets back to the manufacturer.

BTW, playing with this lamp tonight with the dome removed, I noticed something that I haven't noticed on any other LED UV lamps before - a slight whiff of ozone. This tells me that it's producing a decent amount of "real" UVA output. I also measured the voltage at the PC board terminals as 17.6 vdc, which suggests that they're using a series/parallel combination on the LED string. It also tells me that the exposed board with the plastic dome removed shouldn't be a shock hazard.


----------



## Alaric Darconville

PhotonWrangler said:


> a slight whiff of ozone. This tells me that it's producing a decent amount of "real" UVA output.


UVA or UVC? I thought it took short wavelengths to generate ozone.


----------



## PhotonWrangler

Alaric Darconville said:


> UVA or UVC? I thought it took short wavelengths to generate ozone.



There is a specific wavelength within the spectral output of UVC bulbs that generates _lots_ of ozone. However I've also noticed a very faint whiff of ozone with many UVA fluorescent lamps. It's a distinctive fruity-metallic odor, kind of similar to the odor that lithium batteries produce. This is the first time I've noticed this odor from a UVA LED bulb.


----------



## Troy Boy

Hey Everyone,
Im new to the forums and i dont mean to hijack this thread, its just that you guys are on the right topic of what im looking for.

Im a stamp collector, living in Australia.
Certain stamps i collect have a variety of different shades of red. I need to find the best true 365nm uv led globe to use on the reactions. Im currently using a spectroline handheld lab type UV alamp and its just too heavy and annoying.
After researching i see that UV LED technology seems quite good now and im hoping i can get the help from you guys who have tried them all out on exactly which globe to get so i can put it in some kind of flexible desktop lamp 

I look forward to your responses, high wattage would also be good 
Thanks,
Troy


----------



## PhotonWrangler

Higher powered 365nm LEDs are becoming more common now. I have a P60 3W 365nm drop-in for a genericWF-501B host and it works well, with only a slightly annoying unevenness to the beam pattern. It flouresces things nicely. Unfortunately I don't recall where I bought it, but a quick search for P60 365nm drop-in should turn up several sources.

For desk lamps, the CROled edison-base lamp works well (if you remove the UVA-blocking dome, a mistake made in manufacturing material selection). I found it on Amazon (scroll up for the link). The CroLED uses an array of small UVA LEDs. There is another bulb from Sunlite that uses a single high power 365nm LED. It puts out a tiny bit less UV than the CroLED but you don't have to remove the dome on the Sunlite to make it work.

I have yet to find a good _shortwave_ UVC LED that combines decent output with a reasonable price. I still use an externally filtered germicidal fluorescent tube for UVC fluorescence in some minerals (and a few types of postage stamps).


----------



## Troy Boy

PhotonWrangler,

Thanks so much for your reply. I REALLY appreciate it.

The first one you mention, the P60, i see this is for flashlights. This is another thing i was wondering about, as id love to have a small/mini type flashlight with uv 365nm for portability for checking stamps when im not at home. Can you recommend me a flashlight to go with it? I see some on ebay, cree style mini ones with 365nm and they are really cheap. Not sure if they would be any good tho? Would be good not to have to spend heaps as i am young and dont have heaps of cash to spend.

As far as the desktop application goes, i think i found the sunlite one on amazon https://www.amazon.com/Sunlite-A19-LED-2W-BLB/dp/B013W6SJEM but it has only 2W whereas the CroLED is 7W, so im guessing this would make a big difference. Something i want to try and achieve is a strong/intense amount of light so i can have it up high enough on the desk to spread right out over say, an A2 size paper area and for it to work as good as possible. 
Can you give me an idea on how good the CroLED will work in that regard? I can imagine it wouldnt be too difficult to remove the dome cover right? I think worst case i could just break it off lol.

I also found this website when i started researching this idea
http://www.riskreactor.com/365-nm-uv-lights/
If you look there, they have a few versions of bulbs including one which is just a big single LED but its $350USD+ which seems crazy to me. Could it really be that much better? 
They say "1800 uW/cm2 at 15" that sounds pretty good!
I would love to know how that stacks up against a CroLED for just $15

Sorry for all the questions! Hope to hear back from you.
I think for now i will order a CroLED as its not expensive and i think its worth a go 

Troy


----------



## archimedes

Hello Troy,

Your post above has been approved.

By the way, not to get off-topic, but some of these UV emitters are rather powerful and do require the use of appropriate protective eyewear for safety.


----------



## PhotonWrangler

Hi Troy,

I just looked at that $350 UV LED and I suspect there is a misplaced decimal point in that price. I can't imagine a single LED lamp in that wavelength for that price.

Comparing the CroLED and the Sunlite, they actually put out similar amounts of UV. The Sunlite uses a single (probably 1 watt) UV LED, while the CroLED uses an array of about 24 to 25 much smaller LEDs. I'd say that the output of the CroLED is slightly more than the Sunlite.

It's really easy to remove the dome from the CroLED. It's held on by a thin bead of silicone, so it can be pulled or twisted off with only a little bit of force. I think one or two CroLEDs would work nicely for coverage on an A2 sheet of paper.

As for a small 365nm flashlight, check out this light by Nitecore from a reliable dealer.

And here's a more powerful (and more expensive) one from a different (and also reliable) dealer.


----------



## Troy Boy

Hey Guys,
Thanks so much for your replies.
I have ordered a CroLED. Now just on the hunt for a decent flexible arm style desk lamp in black that will fit the E27 screw in.
So hopefully ill get it all done for about $30.

Yeh that really expensive one is crazy ha!
I have also ordered 2 small flashlights off eBay as they are cheap and figure they would be worth a try.
One is a cree style sk68
Other is cree style wb501
Cost me about $12aud for both 

Will wait and see how they go, if they are useless ill grab one of the ones you sent me photon. Be great to have one to take to stamp fairs etc, need to only do 1 stamp at a time anyway

Troy


----------



## Troy Boy

Hey everyone,

Just wanted to say a major thanks to everyone who helped me with the selections of the CroLED for my stamp shade identifications.

I have since compared it to a professional expensive normal style big UV bulb (non LED)
Therr is a slight difference in most ink reactions and bigger differences in others. I feel that the reason for this may be that other wavelengths besides the 365nm that i need for this, are leaking out. 

The other difference between the pro setup and CroLED is that fact that CroLED shows purple on the black cardboard background which i put the stamps on, whereas the pro setup does not show this.

Im thinking that i need a UV filter to make sure only 365nm is passing thru mostly. The pro style setups seem to all have filters so im thinking this is the issue. 

The diameter of the CroLED with the dome removed is 60mm from edge to edge and around 58mm inside the plastic. So I'm looking for advice on what filter to get? I see on alibaba that you can get custom sized ones for fairly cheap (around 60usd) shipped to Australia. This would be 60mm circle so i could glue it onto the end of the CroLED. Maybe i would get 62mm just to have a little wiggle room.

Anyway im really not sure what to get and what would be best for this application so any help would be greatly appreciated
Regards
Troy


----------



## PhotonWrangler

Hi Troy Boy,

Responding to your PM and public post at the same time. I hope you don't mind.

Yes, you need a Woods Glass filter or similar UV-pass filter. I've seen some dichroic filters that claim to have a fairly narrow 365nm bandpass, although I haven't tried one yet. They're actually silver in appearance. B&H Photo sells them in the States. They're probably more expensive than the one you saw on Alibaba though.

It bugs me a little that a 365nm LED produces multiple wavelengths, some of them visible. The whole idea is to produce an invisible light source. Some UV LEDs are even built in a plastic substrate that fluoresces white! I don't know what they were thinking there.

I'll look around form some possible filters for the CroLED and I'll let you know if I find anything good.

pw


----------



## Troy Boy

Hey photon

Yeh, its frustrating! There are so many out there in the way of filters and i really have no clue what to get! 
I'm guessing all UV LED globes probably do the same thing..

Not having to spend lots of money would be great, doesnt have to be the best one you can get, just has to do a good job. You will have a better idea of what i need im sure.

Looking forward to seeing what you can find for me. Thanks heaps


----------



## Lexel

PhotonWrangler said:


> Hi Troy Boy,
> 
> Responding to your PM and public post at the same time. I hope you don't mind.
> 
> Yes, you need a Woods Glass filter or similar UV-pass filter. I've seen some dichroic filters that claim to have a fairly narrow 365nm bandpass, although I haven't tried one yet. They're actually silver in appearance. B&H Photo sells them in the States. They're probably more expensive than the one you saw on Alibaba though.
> 
> It bugs me a little that a 365nm LED produces multiple wavelengths, some of them visible. The whole idea is to produce an invisible light source. Some UV LEDs are even built in a plastic substrate that fluoresces white! I don't know what they were thinking there.
> 
> I'll look around form some possible filters for the CroLED and I'll let you know if I find anything good.
> 
> pw



quality 365nm UV LEDs like SST-10 UV and Nichia for example do not emit visible wastelight
just a faint purple glow as your Eye can see down to almost 380nm

ZWB2 filter is available in 21mm for common flashlight sizes


----------



## Troy Boy

Lexel said:


> quality 365nm UV LEDs like SST-10 UV and Nichia for example do not emit visible wastelight
> just a faint purple glow as your Eye can see down to almost 380nm
> 
> ZWB2 filter is available in 21mm for common flashlight sizes



Hey,
Ad i mentioned its to go on top of a 60mm diameter globe. I went with the CroLED as it was recommended to be one of the best and cheap.

If you can link me to these other globes you mentioned, i will check them out. But with the professional type non LED ones, they dont have lots of visible purple like the LED on the black background, so thats what lead me to think it probably needs a filter

Thanks
Troy


----------



## Troy Boy

I found the SST-10 you mentioned. I dont see how thats a globe? Its a square thing with a dome on it. 
I wanted one i could use in a desktop lamp


----------



## Troy Boy

PhotonWrangler said:


> Hi Troy Boy,
> 
> Responding to your PM and public post at the same time. I hope you don't mind.
> 
> Yes, you need a Woods Glass filter or similar UV-pass filter. I've seen some dichroic filters that claim to have a fairly narrow 365nm bandpass, although I haven't tried one yet. They're actually silver in appearance. B&H Photo sells them in the States. They're probably more expensive than the one you saw on Alibaba though.
> 
> It bugs me a little that a 365nm LED produces multiple wavelengths, some of them visible. The whole idea is to produce an invisible light source. Some UV LEDs are even built in a plastic substrate that fluoresces white! I don't know what they were thinking there.
> 
> I'll look around form some possible filters for the CroLED and I'll let you know if I find anything good.
> 
> pw



Hey dude,

Hows the hunt for filter going?

I was thinking if i cant get that. Maybe should try some other globes? You mentioned that you had quite a few different ones, maybe you can compare them to the CroLED and see if they reflect a stong amount of purple onto a black card. I know that there is always going to be some amount of purple showing, but its so much more than the huge non led globes which is why i think maybe thats why im getting slightly different uv reactions on the inks.

Thanks for all your help


----------



## PhotonWrangler

Troy Boy said:


> I was thinking if i cant get that. Maybe should try some other globes? You mentioned that you had quite a few different ones, maybe you can compare them to the CroLED and see if they reflect a stong amount of purple onto a black card. I know that there is always going to be some amount of purple showing, but its so much more than the huge non led globes which is why i think maybe thats why im getting slightly different uv reactions on the inks.



You know, for a moment I was considering purchasing one of those old incandescent blacklight bulbs and cutting the upper portion of the bulb off to get a globe-shaped glass filter. I thought about scoring the bulb with a glass cutter, then breaking off the top part. But then I remembered what a klutz I am with glass cutting.


----------



## Troy Boy

Hahaha, yeh that sounds a bit crazy.
So any luck finding a filter of any sort for me? I really have no clue what to get.
Also, how about the other 365nm globes you have? Can you see if they work better somehow? Maybe see if they project as much purple light onto black card.
Thanks


----------



## PhotonWrangler

I might go for a Hoya U-360 filter or equivalent.


----------



## PhotonWrangler

I've just ordered a Rosco Permacolor UV-pass dichroic filter # 3660 to experiment with. I should have it in a few days. I'll let you know how it works out.

**Update**

I've received a couple of these filters and tried one out on a flashlight that has the Nichia 365nm LED. The LED generates some whitish visible light as well as the UV content. The filter has some insertion loss on the UV, which I expected, however it does cut down the visible light output significantly. Based on this, I might order a larger filter to fit onto a reflector hood for the Feit bulb.

This filter is a silver colored disc, so when the flashlight is off, the lens looks like a solid mirror. :huh:


----------

