TWO Nichia 219 LEDs on ONE XP-G Star, One Reflector - Fail!

EDIT: I have to report it as a failure. Catastrophic I might add. POOF! I decided to run the thing for a few minutes and one led started to flicker and then die. The other one kept burning, but way too bright. Nothing got too hot. I was checking temp and neither one felt hot, but I could see one pulsing and then die out. I think I will stick to series, or singles. Singles most likely.

Well, it was a test and all tests don't work.

I wanted to do multiple leds, but I wanted to do them in one reflector. Not possible? Sure it is. I had some XP-G bare 16mm stars, so I cut some copper to make pads long enough for two Nichias side by side and soldered it all up.

twins

The strips of copper are 24 gauge copper sheet, cut with scissors, flattened and pre-tinned both sides. I positioned them on an XP-G star and reflowed them onto the star. Next, I put two Nichia 219 leds on and reflowed them to the copper strips.

It works! I stuck it to a big chunk of aluminum and powered it up with 3xAA Eneloops, DD.

The beam shots:

I took a plastic deep reflector I had. It's 50mm diameter and about 40mm deep. It was an SMO reflector, but it had defects, so I happened to save it for something just like this test. I opened up the led hole to take both of the Nichias, not much bigger than an XM-L hole actually.

I set up the led on aluminum by strapping it to a step ladder and set up the camera next to it. All shots were on manual, with 100 ISO, F2:7 and Daylight WB. The shutter speeds are different and are mentioned by each photo. I am hand holding the reflector up to the star, so it's not necessarily held in the right position, just held up to the star and I am sure it's cocked to one side or the other while doing it.

tb1

SMO reflector, 1/2 second shutter speed. It didn't look good.

Then I stippled the Reflector

tb2

Stippled reflector, 1/2 second shutter speed. Stippling made all the difference didn't it?

tb3

One more shot with the Stippled reflector at 1/4 of a second, to see the hot spot better. Looks good to me!

Remember I have yellow walls, so the light really isn't yellow, just the walls make it look that way.

I'm not smart enough to know that you can't put two leds next to each other in one reflector. I just think of it and try it.

I will be doing my next Maglite 1D with Two Nichia LEDs on an XP-G star!

That is pretty cool, Justin!

Nice! I know one member of CPF has made double XP-G P60s before in one reflector. I certainly want this light. ;)

You want all if his lights. Lol. Way to go Justin! It will be interesting to see what color mix you choose and how they blend with an op reflector.

……and I’m also talkin’ about the light! H)

Different Vf’s maybe caused one to suck more juice. That or difference in heat path was enough to make one overheat. Phooey. Do the nichia’s also have the center heat pad like xpg’s?

People always say that will happen but I personally have never seen a case of that happening. Have you?

And yes, they do have a center heat pad. The datasheet is here.

http://www.nichia.co.jp/specification/en/product/led/NVSW219A-E.pdf

I can buy different Vfs. They weren't matched or anything and most likely that was the reason. The pads were all fully soldered down and no shorts. I took it apart after, to loook at that. Heat wasn't an issue. At least best I could tell from feel, but withought a direct heat reading on each, that's not a known, just a guess.

Cheap little 5mm showerhead lights count? In that case I have.

I have always been curious about a dual emitter, thanks for sharing.

what happens to middle thermal pad when you solder two copper strips to power pads. reason for failure may be lack of middle thermal path ???

or are you using Nichia 119 ? 119 have no middle dedicated thermal path.

I made all three pads.