Finally the XHP70.2 emerges!

These drivers PWM at around 18khz IIRC, not super fast but more then fast enough to not be noticeable to the human eye.

I have never looked up the exact rise and decay times for LED’s but it is really fast. At the rates we PMW it is turning all the way on and off for sure.

I suppose it is possible to make it fast enough to not fully turn it on, I have considered this myself. The issue here is that depending on how fast that needs to be you run into losses switching the FET that fast.

You can actually use a normal FET with a few extra components to create a linear regulator that would basically do what you are thinking of but it would also burn all the excess voltage as heat. This is the fundamental problem with this idea. The excess voltage has to go somewhere and I am not sure that it is possible to reach a balance where it is not all or mostly burned off as heat.

now burning it off as heat is just fine, same thing we do with 7135’s but you are also limited in how much you can burn off before you melt the FET. From testing this appears to be around ~2W of heat dissipation in most cases.

It is possible that you could time things just right to PWM it without a lot of losses and still get reasonably good efficiency but I have a feeling that the LED efficiency would suffer in other ways. It would be interesting to test but I doubt that it would be worth pursuing. At the very least you would need to use FET’s with much higher resistance then we use now and that would not be ideal for max power.

Just a quick test on a Jaxman E2L with triple XP-G2. Thorlabs DET36A/M as sensor.

Rise and fall times are below 1 microsecond. The PWM would have to be in the several megahertz range to hide the PWM.

Good info^! So yeah, kinda like I figured, while technically possible to switch an FET that fast you would end up with as much or higher losses in the FET as you would either going with an linear regulator or normal PWM from an efficiency standpoint all things taken into account.

If a super fast FET’ was used or if we used 2 separate FET’s then it could be possible I suppose. Complicated but possible. Although I still have serious doubt that you would gain much of anything tangible from such a setup.

Here are some beam shots you might find useful.

The new 70.2 does have less of a donut hole pattern. It’s not gone completely, but much better than the xhp70.

The first 2 photos below are a direct comparison of the 70 and 70.2 on my L6 with the same reflector height.

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If I move my reflector away from the emitter just a little, the donut hole reduces more. See below.

Now when you look at these lights without the lower exposure, the donut shapes are much harder to see. The hotspot of the 70.2, which is shimmed out looks really smooth and has sharply defined edges.

Here are the same 3 photos as above, but normal exposure values.

I’ve only had the 70.2 in my light a few days and the batteries are already running down. It seems like I’m getting less than half the run time compared to the xhp70. I’m not using it much at full output, then again, maybe I do have it adjusted a bit brighter than the xhp70. I typically go full power then drop it down a little. That way I’m getting close to full brightness, but with noticably less heat. I’ll report back on the battery usage in a week or two. First impressions are it can can suck batteries dry quick! Lol

Brightness is the same. The camera just made it look brighter for some reason. I didn’t notice this at the time. You can see the background lighting and street lighting are all a little brighter as well. I think the color temp of that photo is also a bit different. I’ll try to adjust it to match the others later.

Has anyone tried the XHP70.2 in 4000K flavor yet.

I currently have the Olight R50 Pro with a XHP70 5000k, but don’t like the blue corona it puts off.

Was hoping XHP70.2 4000K might have a more consistent beam.

Can someone please tell me thier experience with this led before I make the swap.

Or any suggestions on a neutral to warm tint that I should consider for this light.

Thanks

I know that the 4000k XP-L2 is far superior to the 5000k version I tried. The xhp70.2 is simply 4x xp-l2 dies put together, so I assume the results would be similar.

I am hoping to try some xhp70.2 myself before long.

Guys, i have a burning question:

When i saw FT has the XHP70.2 N4 3A in stock, i jumped the gun and ordered 3 of them for my MT03, because i really like the 3A tint.
My question is how big the difference in output is compared to the P2 binned versions.
Is it significant?
Should i have waited for an opportunity to get the P2 bin?

(I also got some TIRs for them by the way, i don’t think they will be nice with regular reflectors.)

Honestly you will not be able to tell the difference between bins. At this level of output the human eye is just not sensitive to notice unless you had them side by side.

Do you have some ballpark percentages?

Anyway, i think i’ll stick with these then.
Thanks for answering.

Should be easy to tell from the CREE specs - I do this all the time. I think the percentage increase going up bin to bin is basically linear for higher amps, because the CREE specs will only show you low amp levels.

I think there is about a +–7% for each output bin. I’m not sure what the tolerance is for the 70.2. Anyway, you could get 1 emitter at the high end of N4 and 1 at the low end of P2 and measure almost the same output. Or they could be at opposite ends and you’d measure a big difference. You never know for sure unless you actually measure them.

I had a xhp70 N4 1A and a N4 1C and they were 6% off from each other. One of them was like an extra boost of power. You couldn’t see it with your eye, but you could measure it. It gave me a free 17 more meters of throw.

You might get lucky with a higher bin or you might not. So I wouldn’t worry too much about it.

You did measure different tints though. If you didn’t measure using a calibrated luxmeter with an expensive Filter, the difference might be due to the sensitivity to different wavelengths of your specific lux meter.
Slight differences in how LEDs are soldered (the thickness of the solder plays a role there) might also make a difference.
So in the end one can never be quite sure. :frowning:

I would not think the tint of 1A and 1C would make much difference. They looked identical to my eyes. Wouldn’t it make more sense that they were just at different ends of the N4 binning range?

(Xhp70 output tolerance is +–7%)

This is the wrong mindset.
If you say there is no visible difference between N4 and P2, then you can also say there is no visible difference between N2 and N4, then you say there is no visible difference between M4 and N2, etc etc etc.
Using that logic you will end up buying the lowest possible bin because there is no visible difference from the next one.

As a flashlight enthusiast forum, I would expect people to go for the best possible option, not “oh this one is good enough, no big difference”.
Yes there is a difference, and all the small things do add up in the end.

The Difference betwenn N2 and P2 is at least 7% and maximum 14%. Its the wrong conclusion if you say: if there is no differnence between N4 and P2 there will be no difference between the lowest and hightest bin.
Jason only said that there could be a difference between two binnings but there could be no difference too. Thats the normal shifting in the binning steps.

I've spent a lot of time and money to get an extra 5% output here and there, so a 5% or 7% to me is a big deal. I wouldn't down play 5%, but paying an extra $50 or so to get 5-7% (qty 3 of XHP70.2's) - you gotta think bout it. For a MT-03, 7% can go from 10,000 lumens to 10,700 - not a substantial gain but a bump none-the-less. For a MT03 though, it's worth popping out that pathetically thin MCPCB (1.5 mm at best) and checking the grease and surface under it. Mine had a drop or so that maybe covered only ~50% of the surface directly under the LED's, and the copper was tarnished from no surface protection - not good.

I tore the LED wires getting them out because of poor clearances, and screws holding the MCPCB down can stripped threads in the shelf, and the screws on the battery tube were severely stripped and angled in, damaging the threads.

My MT03 needs repairs to even make it moddable, and all these things you might not know about unless you looked.

You don’t understand, the difference between N4 and P2 is basically the same as the difference as N2 to N4 or M4 to N2.

So if your logic is “why pay more for P2 when you won’t see a difference from N4” then you can also say “why pay more for N4 when you won’t see a difference from N2” and then “why pay more for N2 when you won’t see a difference from M4”

Do you get what I’m saying?

The point is not that you should not aim for the highest bin. Of course you want the highest bin that you can practically get.

The key there is practically get. Getting the positive top level bin is almost always harder then going 1 step down. You are also generally going to pay more and be limited in the tint selection, usually cool white only.

For example Cutter generally had the best bins you will find but they are a nightmare to order from, the shipping makes the prices insane unless you are ordering in bulk and well, the communication is basically non-existent.

All of these things factored together, yeah I have no problem at all going with 1 step down for the best to get an LED that is the tint I want, from a supplier I want and at a better price.

This rule applies to most things in life honestly. Taking 1 step down in most things nets you a rather large increase in the bang-to-buck ratio.

Taking further steps down will end up giving diminishing returns of course.

This is also a budget flashlight site, so bang for the buck is always at the top of peoples lists when it comes to shopping.

Probably a stupid question; when reflowing an XHP 70.2, what is the proper orientation of the emitter on the mcpcb?
Thanks in advance.