Cree R2 LED Dropins

[Justin Case]

This is one way to distinguish between the new version DX11836 vs old version DX11836 -- check the exposed face of the driver. On the left is the new version DX11836. In the center, an old version DX11836. On the right, a DX6090.

 

[phxccw]

Thanks for all of your help...but now that I am thoroughly confused...which LED drop in that is less than $20 be the smartest solution for my G2Z, 6P and G2?
Thanks again guys.

 

[Justin Case]

It depends. I already have some of these new version DX11836 that I got for $7.85 each (I bought more than 5). I also already have a bunch of DX3201 3xAMC7135 single mode 1050mA drivers (20 boards for $28.86, or $1.44 each). So I mod'ed the DX11836 with these DX3201 drivers and the drop-in works great. So per drop-in price is $9.29. But as I said before, this pretty much locks you into battery sources with voltage of Vf+a little bit (e.g., 3xNiMH, 1xLi-ion).

If you go with one of these DX3201 drivers, I would pre-emptively remove the two diodes located in the center of the board, and then solder two short pieces of wire to connect the two pairs of contacts on the driver board where the diodes had been. It is possible that the R2 Vf is less than about 3.3V@1000mA drive current, so you would benefit by removing the diodes. If the R2 Vf isn't that low, then the diode removal won't do anything for you. The minor (IMO) downside is that you lose reverse polarity protection, which was the function of the diodes.

If you want a plug and play solution, then this approach isn't the right one for you.

 

[Justin Case]

This is the driver that came with my 11836. I don't quite understand, though, you say it is putting out near 7V at 2.5A?! and which one of your input graphs correlate to this driver? Thanks!

No, what I am saying is that the board appears designed to try to deliver 7.5V and 2A when running in regulation. Beats me what is going on with that circuit when loaded with an LED with Vf more like 3.5V. Definitely at lower Vin comparable to 2x123A, the drive current is excessively high. The drop-in seems to behave like it's in direct drive, so Iin~Iout. And for Vin up to about 11V, the driver efficiency is terrible.

The graphs for the DX11836 drop-ins that use the suspect driver based on the YB1682 IC are the ones for the "recent vintage" DX11836s and are labeled "DX11836 #1", "DX11836 #2", and "DX11836 #3".

The "good" DX11836s are the older ones that use the same driver as the DX6090.

 

[kramer5150]

Here are input power vs input voltage plots

what the heck is going on in this graph?:thinking:... defective module perhaps?... Current ramping up & out of control?

 

[bshanahan14rulz]

probably for a one-cell light.

at 4.2V driver tries to push out 10W
at 2.6V driver pretty much cuts out.
points in between are strange.

 

[Justin Case]

probably for a one-cell light.

at 4.2V driver tries to push out 10W
at 2.6V driver pretty much cuts out.
points in between are strange.

Definitely not a one-cell driver. Just check the input voltage specs, for example, for the buck converter IC and the diode. Looks to me like it's just a badly chosen driver for the application.

 

[Black Rose]

I used to think that the DX11836 single-mode R2 drop-in was a good, low-cost option. But I've changed my mind. For me, it runs too hot for very little gain vs. the old, tried-and-true DX6090. In a plastic G2Z, I think that the heat generation would be especially problematical.

If they've tinkered with the driver on recent versions of sku 11836, do we know if they've also done the same with recent versions of sku 6090?

 

[Justin Case]

Kramer5150's DX6090 bought about 20 months ago shows that resistor R2 has a value of R20 (0.2 ohms). That sense resistor value should give a nominal 1000mA drive current. If you check the DX web site and look at some of the driver images for the 6090, R2 has a value of R220 (nominal drive current of about 909mA).

 

[kosPap]

guys I posted some measurements of the red version of the dx11836 driber here

http://www.candlepowerforums.com/vb/showpost.php?p=3393698&postcount=263

and damn I forgot to check the sense resistor value before posting

 

[Lego995743]

Can i use this http://www.dealextreme.com/p/cree-r2-drop-in-1-mode-led-module-3-7v-18v-26-5mm-x-29mm-11836 in my g2 with a metal bezel?????