10 W 365 UV LED what kind of driver?

It's nice of you to join us, UVLolo!

Can you tell which led you are planning to use?
But usually the UV-flashlights are driven with a lineair driver from a single li-ion battery, higher power UV-leds can even handle direct drive. 365nm leds have fairly high voltage so the output drops significantly while the battery drains.

Well. I can't figure out how to add a picture because it keeps asking for source but doesn't let me dive into my files. It's a 10W 20mm copper with 3-3.7v. Looks just like a convoy chip but with 4 LEDs. Says Epiled 3535 Ultra Violet.

There's a link in my signature on how to post pics on BLF.

Is this the one? Listing has lots of options, including what you’ve said you have.

https://www.aliexpress.com/item/32979956905.html

If so…well. There’s no problem picking a driver for it but I’m not sure what reflectors might be available to fit that array of leds like that…if there aren’t any then you’d be running it as a “mule” where there is no direction of the light, just a super floody output that won’t reach very far and may reduce the fluorescence you see even nearer to the light.

In the description on this page it says up to 2.8 amps, which is easy to come by in drivers with lots of firmware options. I don’t know anything about these Epiled emitters, maybe Djozz does. In general, they’re pretty sensitive to heat so you don’t want to feed them toooo much juice but with some emitters a little extra is fine. They do tend to eat batteries quickly and between voltage requirements and derating from heat, the output can drop significantly after not running very long (if you’re running it continuously or for longer stretches).

There are some really good UV emitters now and perhaps a single emitter would get you what you’re after. The balance between the size of the emitter and the width/depth of the reflector can be manipulated to come up with a beam type that you want.

Instead of that 4x3535 LED, I just use a standard 5050 LED: https://www.aliexpress.com/item/1005003293174976.html or https://www.aliexpress.com/item/32595356097.html

Thank you! Those look great!

Thank you!

Yes. That's what I was looking at! And then, the post below yours included a link for a couple really nice single emitters as you mentioned.

So then back to the og question, because I seriously know zilch about any of this. I just made my first white light led flashlight last week and used the recommendations from Mtn Electronics for led and driver.

But for the uv light, I want more light. Which I've learned from scrolling through this forum (thank you all you and all your brilliant minded friends out there!) means the driver has to support the increased wattage.

But my brain, although it can MacGyver most things, absolutely stinks at maths. So trying to figure out input requirements for wattage output kind of exceeds this girl's capacity. I'm not even sure I said that right.

I have a couple 17mm drivers with the following parameters: ,input: 3-8.4V, output: 3-4V 1500mA (single mode).

Would those work? Or do I need something different?

Thanks so much for your time!

Your driver will work, yes.
“More light” and 365nm UV contradict each other - I have a 10W 365nm light and it is barely visible at night - the reaction with UV reactive stuff is there, but not much visible light, if you want that.

You can also choose a 3A driver for high output - or a FET driver to drive the LED with more than it is rated for - makes it brighter but shrinks the lifetime and you should use a DTP MCPCB where the LED has direct contact to the copper of the Star you mount it to.

For high quality DIY, http://kaidomain.com is my way to go. There you can get LEDs on DTP boards for cheap, good drivers and hosts.
The absolute classic 10W LED driver is this one: http://kaidomain.com/Flashlight-DIY-and-Tools/Flashlight-Drivers/KDLITKER-7135-V4-17mm-AMC7135-1-Cell-16-Groups-Flashlight-Driver-Board
But like I said, yours will work, too.

More later when I’ve got time to type and surely more input will be shared between now and then, but maybe have a look at this previous thread on converting a Sofirn C8F into a UV light…really all that’s needed is an emitter swap (you could buy a spare copper star with the light from Sofirn on aliexpress, or just remove and replace the emitters it comes with. they’re a normal 3535 die size like XP and there are several UV options in that size). He actually made his own filter lens but they’re freely available now from a few places. The driver in this light can be used as is although you’d want to avoid using turbo since that gives a bit too much juice to the emitters…but high is fine (this light can be set to a nice smooth ramping mode or a stepped mode for output levels).

For longer run times (where heat can be controlled) and slightly more stable output, using a “buck” driver with two cells in series is the way to go, but that can be tough to find. So the input voltage from two cells would be something like 6.0-8.4, but the output would be bucked down to around 3v or whatever (emitters can handle a certain range….too low and they won’t light up, too high and they might get fried…UV is a bit sensitve to the higher voltages and heat). So a single cell with usual drivers has its shortcomings. A “boost” driver, also maybe hard to find for some hosts, tries to keep the single cell voltage at a constant higher level, so as it depletes and voltage sags, the light still runs more or less at the same level…but then when the cell is Done, it just drops out fast without a tapering off of light to let you know it’s done. Boost drivers for single cell to 3v are pretty scarce, though…usually used to boost a single cell up to something like a 6v emitter, so that wouldn’t work for a 3v emitter and would toast it.

Are you shooting for more distance with the light (tighter beam maybe) or just brighter light in an area like a room or along a hiking trail?

btw, Convoy already makes a UV C8 light as do some others (single emitter only). There’s a pain-in-the-arse patent that some jerk was awarded regarding UV flashlights with filter lenses, so many manufacturers and retail outlets won’t ship those to the US if you can even see them on their websites (they may come up in a google search but when you visit the page it’ll be dead or specify no shipping to the US). So yeah…totally doable, but just need to approach building a UV a bit differently than you do with white emitters, which are usually more robust and can handle more abuse.

The rock & gem gang has some of these exact Convoy lights for sale, but at ridiculous prices with drivers that are suitable but not super impressive…building your own is more work but magnitudes less expensive than what they are asking for them.

As for that filter lens, you likely want one of those for the light. They block wavelengths on either side of the target (365nm here) so you don’t get the stray visible light. Sometimes that stray light is helpful depending on what you’re using the light for but generally the filter lenses are nice to have.

Thank you!

Hey! I can't figure this posting thing out. I had a long response typed and thought I sent. But it's not here. Oof.

Very familiar with the uv guy. I have three of his lights. One I dumped in Lake Michigan and couldn't find it for an hour. It works but is glitchy which is why I started this whole "let's build a flashlight!" campaign.

And then of course, it was: can I build a better flashlight than what I've got? Which is how I wound up here.

I believe the patent only covers the selling if this particular model modded with the uv emitter and filter. I'm not wanting to sell. Especially bc you can't find extension tubes for the C8. Simon doesn't sell them, I checked. I'm trying to figure out a work around for that. But that's still TBD.

The 18350 tubes don't have an adapter ring...at least not that I could find. Anyway,the point is, I'm not trying to sell them...

But after all this super helpful discussion,I think I'll just stick with the emitters that Simon sells. I think those are 6 watts. I I did buy 1 10w emitter just to see how it does bc I'm curious. But if it fries or uses battery too quickly, I can always swap it out.

Thanks so much for all your help!

I’d like to find some 10 watt in 365nm that are a single large die under the dome rather than 4 laced together, if you happen to know of a source. :slight_smile:

Here: https://www.aliexpress.com/item/4000542976822.html

That's the one I grabbed. If someone wanted to reflow an existing MCPCB for a 10w emitter, is there a way to look at the board and confirm it can handle the increased heat output of a 10w emitter?

Thank you. I looked all over (more than once) and could only ever find 395s like that in stock.

Mmmm… Sort of. Ideally you would want the mcpcb you are using to be made of copper, and be a direct thermal path type. Especially if your are going to drive the emitter hard in a small light. With white light LEDs you can power a setup on and if the LED does not get destroyed right away, or turn blue ish or have a rapid fall in output, for the most part you can expect it to be okay. With UV that is not the case. You can have none of those indicators present, meaning stable output, no color shift etc, but if you don’t have an excellent thermal path and solid heat sinking, the LED will just suddenly die in a week, a month or what ever.
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Its a pretty safe bet if you have the copper direct thermal path mcpcb, a decent amount of metal, a good thermal path between the mcpcb and the heat sink, and your NOT overdrive the emitter, that everything will be okay. If you are unsure if the mcpcb you want to use is good post a picture and we can take a look.

Turns out this seller is also out of stock on the 365nm single die 5050. The hunt continues :slight_smile:

Seems to be somewhat out of production?
https://www.aliexpress.com/item/1005002344659297.html
that die looks small, more like the 5W XM-L Style LEDs you can find on AliExpress. Wouldn’t run them with 10W

But if you are not using some sort of round lens in front of it, you won’t notice if the LED has one die or 4.