Finally the XHP70.2 emerges!

Correct Tom, on all counts, Same light I posted. Reflector on the board no centering ring, the L6 smooth reflector center’s up nicely in the X6.

I was just looking to see where this LED might plane or stabilize. I moved it around till I got the best/highest LUX reading, just off center, then held it there, plus what it took for my eyes to adjust to the initial blast at 2m, to see the meter, then my normal count of 10 seconds more or less? I wasn’t concerned with ANSI testing, just give it some time to stabilize.

Bottom Line from what I witnessed, is the emitter IS making more Lumens/LUX at 20AMPS then at 15amps. Regardless of anything else, I’m not that Highly Testicle when it comes to flashlights, I’m happy as hell if it turns on! :smiley:

That is T/A’s and Djozz’s GIG! :+1:

I did change the reflector out to the L6 OP reflector tonight and the beam is rather quite nice, very smooth, and floody, I personally prefer it over the smooth.

It sounds like a 26mm or 30mm copper DTP star combined with machining the flashlight head to match might be a good option with this emitter.

Also Narsil, so you can ramp it down just slightly for more practical usage and longer run times (thermally limited).

Your welcome! :+1:
Yep, the X6 has a brass pill, I bored it out and pressed a copper plug into it, machine the surface flat and then soldered the 32mm Maxtoch DTP board on it. Not much room for the driver. Soldered up the threads on the pill and used the host to re-cut them, it’s a pretty tight pitch now.

I’m not most people and I could give less then a shit what anybody else thinks, my test were not for techies,pros or gurus, just for my own experience and out of boredom! So I thought I would post it, that’s all. It’s just a hobby to me! And it sure beats the hell out of doing nothing, at all! :wink:

Hey, the test was a heck of a lot better then anything else that has been posted so far and I don’t think djozz has one to test and I know I don’t so most likely the best results we will have for awhile.

Interestingly the results are virtually exactly what you would expect from 4x XP-L2’s put together from my own tests. They also peaked at 10A (which is what each die is getting in the XHP70.2 @ 20A).

I wasn’t saying that those tests should have been made with proper testing standards for everyone to see.
I was just wondering how long it was on when you took the measurement and what cooling you used so that I could guesstimate how well it would perform for me if I used a big heatsink.

Something to think about:
Every LED has a thermal resistance, the XHP-70.2 has an Rth of 0.9°C/W, so maybe 1°C/W to the solder joint. This means that for every Watt of heat converted power the LED is 1°C hotter compared to the solder joint. In addition to this you have the heat path to the outside of the flashlight.

At 20A and maybe a Vf of 7.5V (I’m guessing here) the LED gets 150W! EDIT: of which around ~80% is converted to heat (see posts below).
So the LED will be 120°C hotter than the the solder joint on the PCB is.
So if your lights are too hot to hold (pain threshold is at 60°C), the LED is at least 170°C hot.

At this temperature, which is outside the range of the datasheet, the LED loses around 25% of it’s output. Basically a big part of it’s high efficiency is wasted at this point.

The relevant power when considering the thermal resistance is the thermal power. Some of the input power leaves as light and so doesn’t contribute to the heating of the die. So only roughly 50-80% of the input power heats the die.

Right, forgot about that.

At these power levels it might be 20%.

So it’s “only” 120°C more.

I have corrected my post.

I think I have one on order from KD but it has not arrived. But I’m not sure anymore now, I have never made an account there so I can not see an order history, and KD does not send order confirmation emails with details of the items.

If it arrives after all I will do a test, but my power supply does not go over 20A and, as I read above in Kawiboy’s posts, that that is not enough, it is quite a performer!! :smiley:

If you have a 12V mcpcb then you can run it in 12V mode which would only need 10A to max it out.

Although while it may survive that high I can guess that running it above ~15A is going to be a matter of quickly diminishing returns to the point of silliness when you factor in the heat it will produce.

[quote=Texas_Ace]

The 15A buck driver you developed is starting to make a lot more sense now. :wink:

You flashlight mad scientist!

Meh, it came as expected . there was so many naysayers saying it wont happen but knowing Cree , getting Xhp70.2 was only a matter of time and cost.

Now i plan to pop one into a Boss with 4x26650 16v DD on a beefy 50mm thick chunky heatsink to get a whopping ~10k lumens single emitter compact thrower worthy of a flasholic envy. :+1:

This is what i call ‘Pushing on the limits of existing technology’. Doing anything less would be better off going the way of buying a production light.Why bother……

sorry, i dont keep up with the topic
if i change all the XHP70 in my olight X7 to XHP70.2, how many lumens i will gain, and is it worth doing

Nobody has done tests yet.
It will also depend if you’re using a CC or DD driver.
If it’s CC then you will get an efficiency increase and probably very little additional lumens, if it’s DD you will get an efficiency decrease and much higher output.

Link to the driver?

:+1:

Vinh at Sky Lumen got a batch of these 70.2’s in and has already made a few 20k+ lumen monsters.

:+1: