My 360nm 8LED Xnova UV

Yesterday my 8led xnova came in the mail from hongkong, so I modded it that day with FoxUV 360nm UV LEDs. :huh:

I measured current at the tail cap w/white leds, and saw 480ma on a NiMH AA. With the UV leds it drew 470ma. So the Vf is about the same as whites. Say the circuit is only %50 efficient with 1AA, (470ma * .5)=(235ma / 8leds)=29ma per led. So the circuit might be better, I don't know. But at least the leds are driven at spec probably. I taped off all but the center LED and compared it to my dorcyaaa w/FoxUV and it was about as bright, so each one is driven close to the same as the dorcy drives one led.

Ok but what about the output? Well, visable light is next to none. It will show a slight dim whitish light on things that do not glow. Things that do glow though will react pretty intensely. It will also light up things that 395nm lights wont. Plus you don't have the extra purple light to throw off the contrast of the glowing objects. The bandwidth of the led is very narrow like they stated. (most light is 360nm and doesn't spill into 350nm or 370nm very much). A florecent black light tube peaks around 360nm, but also emits other wavelengths of UV. This LED seems more "clean", with less purple visable light than the BL tube..

It seems very dim, until you shine it down at your feet and see your white socks glowing like crazy. To get a feel of the output you really have to shine it on fresh washed white sheets as that's only when you'll see all of the reflected light back. Oh yeah, sunglasses and eyeglasses block all of the output coming out the front. So you can test your shades with this.

The beam angle is pretty narrow, 8leds produces about the same beamspot as one led. Nice round even circle. My xnova 5led w/395nm leds produces a much wider flood compared to these.

All in all it's pretty nice. Not the sheer output of the Nichia 1Watt 365nm power LED, but at least it doesn't cost several hundred dollars! And you have black light bulb wavelength w/throw that will fit in your pocket! Great for inspecting things close to mid range (8-10feet probably max).
Well, until the next mod! :wave:

How To Mod the 8LED Xnova:
The Xnova 8 LED was purchased from Emilion, and is the silver "Type R" edition. The threads are very nice and the tail cap is smooth and tight. The light was a nice even white with a tiny bit of blue tint. The brigthness was pretty good. If I wasn't a flashaholic, I'd think this was an awesome light. Great for gifts for people who don't have high powered luxeons/etc. I like the form factor as the larger head gives you something to grip.

The bezel is pushed in, and I used a bench vise on the bezel and my hand on the head to pull it out. The bezel is chromed plastic and not metal like the 5led xnova I have. So there was a few scratches as I didn't have a rubber jawed vise, but not bad. The freeze method probably won't work as the bezel is pushed in pretty far, the 5led ones only needs a tiny bit of travel to come out vs this one.

After getting the bezel off, becareful not to loose the parts. Below the LED/circuit coffin there is a spring and a brass(?) contact ring. The contact touches the body tube (head unscrews from body) and the spring pushes against it and the circuit.

Once you pull the LED/circuit coffin from the bezel, take a razor blade to cut the black plastic ring in the center of the boards. Once it has a split you can bend it away from the internals and set it aside. Now I cut the LED lead that was soldered to the bottom circuit board in the middle, and de-soldered the black wire that supplies postive power to the leds from the led board.

Now you can put the LED board in a vise and desolder the LEDs, and re-solder new ones in. Take small pliars and pull on each led as you heat up the back side leads. Then when you put new ones in, you'll have to trim the leads a bit, and push on the LED as you heat up the back side of the solder on the board to slide it in flush. Make sure you're putting the LED's in the right way (polarity) and they are flush. Then hold on them and add some extra solder so that back side leads are well soldered like the original ones. When you're done go a head and clip the leads all the way flush. Check for shorts with a DMM on resistance mode (to make sure no solder touches other solder).

Now instead of leaving a lead long on the middle LED and having to de-solder the spring on the circuit and pushing it through, I just soldered a new wire to the exsiting lead sticking up on the boost circuit board up to the LED board. Now re-solder the postive wire in the right spot. Wrap the black plastic ring around the guts of the deal, press the bezel over the LEDs, and align it up and put it back into the head. (brass ring first, spring, circuit, bezel). Since the black spacer is cut and there's no stiff lead from the LED holding the boards together anymore, they will wiggle around until you get them lined up and into the light.

Press the bezel in flush, screw the head on, drop a battery in, screw the tail cap on, and be dazzeled with your newly modded Xnova! :rock:

Remember, you can use these directions to put ANY LEDs into your light. Make a bright green one!, or put the new Nichia CS LEDs in there for 30+ lumens! It's now up to you guys! :nana:

Where can we get some of these FoxUV 360nm LEDs?

Jeff

Jeff, they sell them on ebay right here. They also have a website. http://www.thefoxgroupinc.com/. Prices are cheaper now from when I got some as there's less bids for some reason. I guess everyone got some that wanted some. I'm sure now that will change with this post.. hehe
They are located in Canada, and make their own LEDs. Craig tested this LED and it showed to not have a noticeble drop in output after 100 or so hours!

A cool idea is 20 of these leds, in a small project box/light with 2AA powered by a 400ma micropuck H.O. so each gets ~20ma.

Cool mod! :thumbsup:

IsaacHayes said:

Jeff, they sell them on ebay right here. They also have a website. http://www.thefoxgroupinc.com/. Prices are cheaper now from when I got some as there's less bids for some reason. I guess everyone got some that wanted some. I'm sure now that will change with this post.. hehe
They are located in Canada, and make their own LEDs. Craig tested this LED and it showed to not have a noticeble drop in output after 100 or so hours!

A cool idea is 20 of these leds, in a small project box/light with 2AA powered by a 400ma micropuck H.O. so each gets ~20ma.

Click to expand...

I just tried bidding on one of these and found that somebody is running a 'bot and outbids me instantly. For all I know it could be the vendor.
:thumbsdow :toilet:

I think you can do something on ebay, where you set a maximum bid, and if someone bids higher than your current bid, ebay will automatically bid higher for you.

Kryosphinx said:

I think you can do something on ebay, where you set a maximum bid, and if someone bids higher than your current bid, ebay will automatically bid higher for you.

Click to expand...

Yeah, but I'm not gonna have my bot fight somebody else's bot. I'm moving on...

I have sent them an email to see if they have bulk (200-500) discounts.

Paul

You math kinda is off.... 470ma @ 1.5v to drive a ~3.5v LED at 235ma doesn't work
If you convert the 470ma x 1.5v to mwatts you get 705mwatts. Take 50% of it for 353mwatts and divide by 3.5 you get about 100 ma total. or about 12.5ma/LED, not even close to 29ma.

Greg: Thanks!

PhotonWrangler: A person can set thier max bid, and automatic bids generated up to a bidder's maximum will occour, until someone bids higher than their max. So it will keep jumping instantly until you break the persons max. It will bid just enough to beat you each time automatically.

Chimo: great idea. Someone doing a group buy could get them cheaper for all of us. I wouldn't mind having more, but I'm poor right now. I'd like to go all out and do a huge grid of them DD 3xAA in a project box!

Lynx: Hmm. I was just doing a rough guess. I take it then that the circuit is more than 50% efficient, as each LED is driven as bright as my DorcyAAA with the same LED. I know my "math" isn't really accurate, that's why I picked such a low efficiency number into the calculation (50%). I was going to measure the current going to the setup, but didn't feel like setting up a test rig, as I wanted to just get the light done.

I can vouch for the bidding on ebay part. I just won an auction at start bid $18. Right before IssacHayes posted this review.
THANK GOODNESS you didn't post it any earlier! No wonder there were more bids on their auctions all of a sudden!

IssacHayes: "The beam angle is pretty narrow, 8leds produces about the same beamspot as one led."
I mentioned before that I wanted to use the leds for a custom ordered Peak Matterhorn,
from your statement, does this mean that it doesn't make any difference at all whether I order a single led or 3 led or even a 7 led McKinley?
The end result will still be the same?

Also, I understand Peak Hi-power and Ultrapower models are driven at 30mA and 40mA respectively.
Since these bulbs are rated at 20mA, does this mean I have to ask that Peak builts me a standard power light?
What would be the results of driving them at 30,40mA?

Could you try to explain to me in simple terms? I'm a moron when it comes to really technical jargon.

Thanks!

icebeng: lol, I even stated in this thread that the bids would go up!! I secretly wanted them to stay low incase I got more funds to get more leds!! lol!

The more LEDs the better. You need the extra uWatts of output. It will help. I meant that the beam of one, is a nice tight circle. With 8 leds it's still a nice circle and not a floody beam. The hotspot does get larger the more leds you use, and it gets brighter. Go for a 3 or 7 led one. Ask peak what the drive current is for each led of the Hi- and Ultra power is when you are using 3 leds, or 7 leds. I take it 30/40ma is the rating in the single LED lights. The 3/7 led ones surely won't be that high as there is more LEDs... You want to probably go with 20-25ma per led, 3 or 7 LED light.

I don't know how these do with over driving. I know they last well at standard current though. Like I said shoot for as many leds as possible, 20-25ma each. To get that much current to them in a multi-LED light you might have to go with Ultra power.. I'm not sure ask peak to be sure...

I hope you understand that.. If not ask more questions!

(if I go offline I'm either modding or turned off the PC. There is a terrible wind/lightning storm right now).

Thanks a whole bunch IssacHayes, I understand!

I was having a minor headache trying to decide how to use the 10 leds when they arrive.
Especially since I was considering a single led Matterhorn(for the long runtime) and a 7 led McKinley.
Now that's resolved! 3 led Matterhorn + 7 led McKinley = no spare leds to "agonise" over!

chimo: if they do agree to a bulk sale, could you sell me a single led?

I don't think you need to worry about getting a single led for long runtime. As you won't be walking around the house with these to see where your going, well unless your house is painted with neon florecent paint and your carpet is lined with white socks! lol. These output a lot less power than a 400nm near uv led for example. So the more the merrier!

A 3led and a 7 led one is a good combo, as the 7 would be the output king, and the 3 would be small enough to fit on a keychain and EDC.

Isaachayes,
I figure probably about 60% efficiency but adding in battery sag or using nimh the voltage drops to 1.3v or so it may come out about the same. Most likely between 12-15ma/LED which is probably more light/ma than overdriving it anyway. You also have to take in effect the meter adding resistance in the circuit which would mean the actual circuit is putting out more ma than you measure.
When using UV LEDs it is probably an advantage to underdrive them to increase the life of them. I once put two nimh on an xnova and it was way bright, it could be if you wanted to try overdriving them using a resistor and a li-ion you could find the sweet spot for extra output vs too much overdrive.

Lynx: These UV leds last well at normal drive level compared to some UV leds. But I don't know how they'd tolerate overdrive. I was just thinking of a 3.7v li-ion.. perhaps a micropuck wired as a buck circuit (you can do that, check the data sheets) in place of the stock circuit, and a 3.7 li-ion. That'd be cool! A huge cluster of these in a QIII or something would be excellent as well..

IsaacHayes said:

well unless your house is painted with neon florecent paint and your carpet is lined with white socks! lol. These output a lot less power than a 400nm near uv led for example. So the more the merrier!

A 3led and a 7 led one is a good combo, as the 7 would be the output king, and the 3 would be small enough to fit on a keychain and EDC.

Click to expand...

DON'T tempt me! PLEASE!

I've been reading the other threads about glow paints and such and this might cause me to do something insane!

...... white socks lined carpet..... sounds comfy...... Hmmmmmm..... Nooooooooo.........!

I'm going to try and see if I can get a few of these for some mods I wanted to do.

Jeff

I have made contact with the company and can get a bunch of these for less than the ebay price. Any interest in a GB?