Need to find a UV LED to replace XHP 50.2, Does XHP 50.2 = 5050 LED?

So I recently got a Sofirn SD05 to play with and do multiple fishing related reviews. When I showed it to my fishing buddies, they wanted to see what UV looks like under water, so I am ordering a second SD05 to reflow a UV in place of the XHP 50.2

I’m assuming that the XHP 50.2 used in this light is a 3v version and has a footprint of a standard 5050 LED. Please correct me if I’m wrong.

Anyone know of a UV LED that can handle the current this light is providing for Low/Medium/High modes? That I can reflow or get a MCPCB with UV flowed onto it similar in base size as the XHP50.2?

I’ll try to test the current it pulls to get an idea.

But for now on the XHP50.2 (measured on fresh 4.2v fully charged Sofirn battery with Texas Ace Lumen tube calibrated with Maukka lights)
High - 2260 lm
Medium - 830lm
Low - 240lm

Found a previous review that shows A at different modes on the original step down version.

LOW: 0,44
MED: 1,70
HIGH: 3,60

Xhp50.2 is 5x5mm thereabouts so 5050 footprint.

I can’t say whether a uv will pull the same current. Xhp50.2 in 3v can easily draw 15A in direct drive with a stout 26650 or 21700 in low resistance setups.

Hi Yogibear

XHP 50.2 in mine is 6V, I think they are all like that but may be wrong.

Are you thinking about bio-luminescence?
Blue light is better but disadvantage is that you need a yellow filter.
See my post here, you can try it. You will still be able to convert it to UV.

The XHP50.2 typically can be configured (on the MCPCB) for 12V or 6V operation, but there also exist 3V variants. I do not know which version Sofirn is using in the SD05 flashlight.

However, you're going to be hard pressed to find any UV LED that has the same footprint as the XHP50. Even if you do, you'll have to ensure that the driver is compatible with the driving specifications of the UV LED, which is a fair bit different from white LEDs.

I'm assuming that the main idea is to stick with the SD05 host for your application, so my suggestion is to keep the host, and instead of reflowing the MCPCB, swap it out for a 3535 UV LED instead which are much more common. You'll find to ensure that the driver you have can safely drive the LED, or swap it out with one that can. Nichia makes some very good 365nm diodes.

UVLEDs are very sensitive to overcurrent, so keep that in mind if swapping in even one that physically fits.

The problem with finding a driver for this light is the magnetic switch used for the light. I’m not sure how they implemented the switch. If it is part of the driver I’d be hard pressed to find a driver that can do this. I have found a chinese made MCPCB with a 5050 ft print UV that can support 3A imput. This light has a 3.4A output as measured so the UV should be fine. However I was under the assumption that it was using a 3V XHP 50.2.

If the other post that says its using a 6V XHP 50.2, I’d be out of luck finding a 6v 3A UV LED to mount in it.

I’ve looked at 3535 UV, but they barely can handle 1A input.

Yeah I’ve read that as well. This is looking to be a challenge. If I didn’t have to stick with the factory driver due to the magnetic switch, I’d have a lot more options to mod this lamp.

For the UV LED you could try LZ-00UBOR or LZ-04UV0R
They have unique footprint but you can order them on 4-channel star and connect all in parallel, you will get 4A max current rating.
They should be available on Mouser or Digi Key.

Tha beeing said UV LED has higher Vf than white. May be more than 4V.
Assuming some SD05 are using 3V led that would mean buck driver or linear and it may not work with UV LED (you would get a light but not regulaed at least on high just about direct drive when LED does not get enoug V for given current)

I agree with you about driver. I doubt replacement can be found unless Sofirn steps in.

Hmmm how easy is it to remove the dome and the phosphor? I’m guessing removing the dome/phosphor can ruin the LED? I’ve never done it before so have no idea how much pressure etc…

Very easy. I just unscrewed bezel and pulled on dome with small pliers then scrapped with wooden stick.
This is flip chip led so no bonding wires, most outer layer is sapphire substrate so it is hard, in theory you wouldn’t even scratch it with metal but I didn’t tried.

Edit: just don’t press too hard on LED, I don’t know how resistant it is to pushing it. I pulled a dome grabbing it (it is silicone or something alike), then gently scraped phosphor and wiped it with Arctic thermal material removal fluid because I had it lying around. After looks like on picture, pretty clean I think. Not sure what would dissolve (at least a bit) phosphor without damaging surroundings but I didn’t need it.

Early batches of Sofirn SD05 use XHP50.2 6-volt (it is basically similar to the earlier SP33 XHP50.2 which also uses the XHP50.2 6volt LED), they are limited to around 6 Amps max current drain.

Later SD05 (I'm not sure when it changed, but probably sometime around December 2019 to January 2020) apparently use XHP50.2 3-volt LED), they are noticeably brighter (when comparing th older 6-volt SD05 and newer 3-volt SD05) on Max brightness. The old and new SD05 look exactly the same though, I was able to surmise the differences when I tried comparing an older one with a newer one (I notice the newer one was much brighter when doing side-by-side comparison with full battery; and then I tried measuring their tailcap currents).


Another method to find out the difference is:

- older SD05 does not have PWM in all brightness levels (similar to earlier SP33v2 XHP50.2 behavior, which use 6-volt LED)

- newer SD05 has "fast" PWM in all brightness levels (even Highest level appears to have 'very fast' PWM - similar to newer SP33v2 XHP50.2 behavior, which use 3-volt LED

( I'm only using 'shine light thru a small portable fan blades" to check PWM )

d_t_a

You right, didn’t know, just checked my newest one, 3.05V on LED on hi

I don’t see any PWM though, even thru camera, maybe I’m insensitive :slight_smile:

Do you know if they changed it together with removing 3min timer or earlier?

The old one has blue PCB and new one green, any significance to that?

Hmm interesting. Maybe the 5050 UV will work after all. But it maxes out at 3A.

Will need to test mine. It is newer and does not have the 30 sec step down.