Help with NBBx2 driver and LED upgrade.

I am not sure if I should post this question here or in the Custom Flashlight page.

But either way, my question pertains to the NBBx2 driver and the 27LT with a LuxV

The third light in the McLuxIII-Series, this time with the McR-27L and a DBx2 driver. Think of it as a hybrid between the PD and the HD45 on a 2x123 chassis. Comes with a LuxIII UX1K and offers extreme toughness and technical finesse. Alternate versions include the LuxV variant with the NBBx2 driver as seen on the HD45 above ... and ... the McLuxIII-27LT-S with the Seoul P4 LED instead of the LuxIII.

I recently acquired a 27LT that I thought was a S version with a Seoul LED but received it to discover that it was the LuxV version. The S version is easy to mod to a newer LED with the DBx2 driver, but the LuxV has a more solid heatsink so it will prove a bit more difficult.

The real question has to do with the driver. As a test I hooked it up to a XML and a XPG to see what the current measurements would be before finalizing the setup. They were through the roof as though the LEDs were getting a direct drive with only the Kiroy connected. With a single LiIon the XML measured at ~1.6A. With 2xCR123 it measured at ~2.1 A.

I imagine that has to do with the much lower Vf of the Cree leds. Does anyone have any other thoughts on this that would help with this LED upgrade?

I think I may have found my answer based on the Vf of the LuxV

http://www.luxeonstar.com/v/vspfiles/downloadables/ds40.pdf

Average Vf of 6.84v would explain with a lower Vf causes issues.

Now what to do for a solution to drive a XML or XPG.......

Hmmmm..... I guess no thoughts.

I came up with one idea I remembered after browsing on Cutter's site a while back. What about using a XM-L EasyWhite LED?

http://www.cree.com/led-components-...dules/XLamp/Data and Binning/XLampXML_EZW.pdf

They are binned at 6v and 12v because they are multi-die LEDs (I would imagine wires at 2S2P and 4S respectively).

Maybe the MC-E is another possibility as this can also be wired like a lux V 2S2P?

I have used the XM-L EasyWhite in two 5W mods so far, and they have turned out well. I like the XM-L EW better than the MC-E because the dies are smaller and closer together, making the beam cleaner IMO.

Thank you both. I never considered the MC-E but that could be a viable option if the XML EZ doesn't work out.

The PDF of the XML EZ indicates that it has the same output pattern as the regular XML so I think it will work well with a McR27S reflector installed.

I managed to find a 6v 4000K U4 binned at 85* so I am anticipating its delivery. That is showing 340 lumens at 700mA. Up to 4000 lumens right at startup.

Ill report back on my progress.

Derek,

as a side question can you tell me if the easywhite mods you did we're on drivers orinpginally designed for LuxV 5W lights?

ShineOnYouCrazyDiamond said:

Derek,

as a side question can you tell me if the easywhite mods you did we're on drivers orinpginally designed for LuxV 5W lights?

Click to expand...

Yes. Both lights used the stock 5W converter boards. One was a SureFire KL4, and the other was McGizmo HD45.

Derek,

I got the EasyWhite XMLs in today and worked on the mod and everything was going great until I got to the focus and the reflector. Big issues. Basically the same issues as back when the MC-E came out. A cross shadow in the middle of the beam. Also not very good focus, but I can work on that a bit. I've tried a McR27S and a McR27-Long. The only one I haven't tried is a McR27XR which I don't have but I am thinking may make a decent focus.

Before I go ahead and order the McR27XR do you have any thoughts that may help here?

The XM-L EW requires a heavily textured reflector to eliminate the cross effect completely. Both the Surefire and McGizmo HD45 that I modified had textured reflectors. The McR27 reflector that I experimented with on my own was heavily textured, too. (I don't remember whether it was a Lux, or Seoul version.) What I have found is that the LED must sit into the reflector further than some other LEDs. I use a small copper shim and an 8mm datiLED XM-L board to allow the LED to sit high enough in the reflector opening.

Being that the dies are smaller and closer together, the XM-L EW is much easier to focus than the CREE MC-E, or Seoul P7. With that said, it really depends on the reflector. A light that originally came with a 5W Luxeon LED should focus the XM-L EW well, given the size of the die. I haven't been able to focus the EW in a McR20 reflector yet, though I haven't tried turning the reflector down on the lathe.

Try raising the LED into the reflector a little, and see if that helps.