I believe they do, but I imagine at some point they probably fry.
EasyB, I wouldn’t use that many 7135’s, basically a FET+4-6 set up. Low modes on 7135’s, and FET “turbo” that is limited by a bit of pwm trickery to keep the amps in range.
The hosts I would be looking at should have plenty of room for copper attached to the 7135’s for sinking.
So maybe this is the way to go? I could also just not charge the batteries all the way if all else fails.
Theoretically, 700mW is about max for a 7135 to dissapate but it needs up to 1000 mm^2 of connected trace area per chip to do that or a sink large enough to soak it up. I don’t think it’s feasible for 4s cells since max overhead is ~ 4V and 3s cells drops out right away. The problem is that the more cells you put in series the greater the voltage difference between charged and depleted. Best available option is probably the H6flex with 1,5A per led.
I too was wondering how a MTN MAX buck driver @ 2.5A would make out running three XHP in parallel with four Series cells.
Maybe a couple of CN5611 ?
They can do CC from 40 - 800 mA.
With these kinds of voltages their voltage drop is not a real problem i.m.o.
Interesting. I don’t think that would fix the heat dissipation issue, though.
I like the adjustable current capability of that regulator. One could have an external adjustable resistor and be able to continuously adjust the constant current to the LEDs. With the proper host and switch implementation, that could be an ideal user interface, without even using an MCU. You could immediately put the current anywhere you want based on the position of the adjustable resistor, and also adjust at what brightness it would turn on.
One thing about the XHP35 in mods is that most mods use normal centering rings and thus keep the same focus as other emitters. Based on the fact that XP-L HI’s are so touchy with focus I think that some of the variation in throw with the 35 is focus.
Like was said until the 35’s none of the factory lights were reaching the throw numbers they are today.
All of that out of the way, I think I have come over to using an FET driver with the duty turned down to that max amps is about right as the best way to drive these in modded lights. The Texas Buck driver looks like it will work well but one thing we know is it will be expensive (Like $15+ in parts alone).
I would rather use $5 in parts for an FET driver with PWM even if I don’t get as many lumens OTF. Plus the tint seems to improve with higher currents anyways.
I actually plan on buying an XHP35 to try with a FET driver with PWM vs regulated current to see exactly what happens and how much efficiency is lost.
I’m interested in your findings TA.
Maybe I should skip the SP03 and go straight to the R60T? 4 parallel 26650’s (converted to 4S) and six XHP35’s sounds like a winner to me!
Those reflectors could be a fair amount larger, shame they didn’t use the full size they had to work with.
Now sure when I will get in the parts to do the tests with the XHP35 or what the results will be but should hopefully get around to it in the next month or so.
A little late to the party. Recently I bought an Armytek XHP35 HI Predator Pro V3. They claim 1700 ANSI lumens (i.e. OTF).
It’s slightly smaller than a C8 reflector.
I also have a Convoy C8 running a direct drive XP-G2 (pulls 5.5 amps on a 30Q). And I’ve just also built another Convoy C8 with an XP-G3 and an Kronos X6 driver, it pulls about 5 amps tailcap.
The two Convoys are almost identical in terms of beam profile, hot spot size, throw, spill and flood. The only way I can tell them apart is the XP-G3 has a some what yellow corona around the hot spot.
Both C8’s are running OP reflectors, but I struggle to believe this makes a significant difference.
The Armytek has a bigger hot spot than the C8’s, but also out throws them and has a brighter spill beam. I wouldn’t say it’s a night and day difference, but the XHP35 HI does seem significantly superior by any means I can measure or visually assess them. Apart from maybe tint, the XHP35 HI is a claimed 5000k and is quite nice, but does seem to be cooler than the XP-G’s.
XHP35HI on the left - XP-G2 C8 on the right
XHP35HI on the left - XP-L HI Kronos X6 on the right
With 4 batteries serial
I prefer the LD M2
4s//7,5-8A
and the 3 XHP 35 Leds paralell.
Regards Xandre