Has anyone mixed emitters in a multi-emitter light?

I have a couple of plungers and one more on the way that I’m going to be playing with when my new emitters show up and I’m wondering if anyone has tried mixing emitters and how would it work. For instance I have a 9T6 ($53 on e-bay) on the way and I’m thinking about de-doming 3 XP-G2’s and putting them in the three inside reflectors to see if I can get a little bit of throw and possibly add a little bit of a neutral tint as well. It’s only 9.5amps so at most 1amp will be getting to each emitter. But what I’m wondering is will something funky happen like those three getting too much or something. I’m not even dead set on which led’s I want to swap or change around. It just seems like it will be fun to play around with. For instance I could put 6 de-domed G2’s on the outside and leave 3 T6’s in the middle and shoot for a big spot.

Yes I have… In terms of tint and CRI there can be advantages if you mix in warmer emitters. If you just have de-domed emitters you can not expect higher CRI, but slightly less cool beam in total.

Problem is when you start mixing several different types of emitters with different vf (forward voltage), you easily risk that one type of emitters get way more current than the other type.

I recently tested to mix in 1 XP-2 with 4 XP-Gs. Tested with only 3amp input (divided on the 5 emitters wired in parallel). At startup the XP-G2 got half the current (1,5A). After a short while it was down to around 0,6 if I remember correctly. Since I had plans of higher current, I found it safest to not mix XP-G2 with the XP-G emitters despite that they actually seemed to level out fairly good. But I did not use much time to check the behavior accurately, so don’t quote me on that exact setup.
But thing is, if the one XP-G2 had 1,5A of the 3 amps. The other 4 had 0,375amp (1,5/4). Again, that was only at startup, but it shows how easily one type of emitter can get a lot more current.

You can see vf charts on Cree`s webpage for the various emitters.
You will also find graphs here but some are measured results from Match.

As you can see, small increase in voltage can make a huge increase in current.
Since XP-G2 and XM-L run can run at slightly different voltages (when you compare the same current) , you can not take the total amount of amps and just divide them on all the emitters. I would guess there is a high probability that the XP-G2s would get (way?) more current. One can do the calculation in theory, but best thing is the measure the emitter current yourself in your setup. So the best way is to wire everything up and measure how many amps go through the XP-G2s and the XM-Ls. Start with XP-Gs, Id guess the current would be higher in them.

If you wont bother with the measurements just copper mount the XP-G2s. Then you should have no issues to worry about, despite the possible differences in current to the emitters.

Hope this helps, and since Im not fairly noob-ish at all this, someone correct me if Im wrong… :slight_smile:

What? Where ar the 9 Amps? I doubt you are correct.
Normally in these multi emitter lights they are soldered not all parallel or serial.
The 9T6 with three batteries, I have seen so far used 3S3P so every LED would see 3A.
If you now think I just swap these three emitters, wire them serial and go for it. This can work but these 3 LEDs see a voltage between 10-12V…
Now you could compare the forward voltage of the XMLs and the XPG…could be lead to problems maybe not

But I am sure this can be done, you can even put an additional driver in the light, there is space enough, a bit tricky with the modes maybe.

XP-G and Nichia mixed: Quad XPG/Nichia direct-to-copper

Mixing in some de-domed emitters sounds like a great idea.

I’ve only mixed 1 warm xml into a SRK and into a TR-3T6. I have the emitter on the bottom when I carry it. It helps reduce near-field glare and improves color rendering some. It did seem to help de-cool the overall beam tint too. Decreased overall output a little, but a worthwhile sacrifice to me.

I don’t know how the math works but I don’t see a 9 led plunger putting out even close to 9,000 lumens which it could if each led was getting 3amps. I doubt it’s putting out even half of that.

Can you explain how 3S3P works in regards to amps because I clearly am missing something.

Thanks this is what I was wondering about. How much more current will the XP-G2’s draw. Hmmm. I guess there is only way to find out and it involves buying a new DMM because mine is so far off it’s only good in a relative way.

One more question this driver is supposed to be 9.5amps with three batteries in can you tell me how many amps each emitter gets if I use all the same kind. For instance I have a 6T6 that originally came with a 9amp driver How many amps was each emitter getting? Does it matter then if it’s all T6’s vs XP-G2’s?

The driver in the 9T6 is simple a FET which is switched on with a Controller, the different Modes are made with PWM. You only get the 9A with a copper raid on the positive spring and with fresh totally charged batteries.

3S3P means: 3 LeDs in Series are one group and 3 of these groups are in parallel.


Body-- |--led----led----led----| ---3 batteries----Driver -----switch----body


Looks like that(but it Should be a circle..you know)

if you are now measuring 9A between the switch and the body(tailcapcurrent) than that is the total current which is splitted in 3 parts(you see the 3 paths which are parallel). that causes a current of 3 Amps through every path.

the current is splitted equal because of the symmetric design and equal LEDs. If you imagine to switch one group of LEDs through a simple wire all the current would flow through the wire because current goes for lowest resistance...that would cause high current but no light.

If you now imagine to switch one group through another LEDs which are not equal, than that could cause a similiar effect or it could cause the opposite(if resistance/forward voltage is higher).

But I think it is worth a try and a good idea. Trying different setups and measure it with a DMM, sounds like a good way to go.

Remember that the LEDs in the centre don’t actually contribute anymore to the hotspot than those at the edge, each one produces a full spot and flood beam which is overlaid on each of the others’ too.

In fact, light directly from each emitter spreads evenly throughout the entire beam, but the very wide angle light that a bare LED would put out further to the side is collected by the reflector and redirected to the hotspot area. With most multi-LED lights it’s actually the LEDs around the edge which have a greater amount of reflective surface in the line of the LEDs natural spill. So, if anything, those ones around the edge contribute more to the hotspot than the ones in the centre.

Thanks that makes sense.