Interesting. I thought the H1-A didn’t output high enough voltage for three 3V emitters in series. I should get one too then.
It doesn’t as they come straight from KD, but if you change the 47k FB resistor to a 75k, it does it without issue. Been running a few 3S triples this way for a couple of months now with no problems. Still very efficient too.
Super, thanks!
Did you also changed other resistors to get more Amps?
I changed the R025 to an R030 to reduce the current, since all 3 emitters see the full current.
ThorFire TA13 lens measured at ∅31.5mm outer, ∅26.5mm effective inner, 8.1mm thickness. Pocket friendly.
Its o-ring is also of 31.5mm outer diameter, 1.5mm thickness. Water tightness seems good for a zoomie.
Cheers ^:)
Originally posted on Fri, 09/15/2017 - 18:40. Edited for a lens measurement data fix.
Peeked more in-depth in the TLF SF30A review & modding thread khas linked. My modded TA13s should be achieving ≈50Klux fully focused, considering ≈20W reach their XHP35 HI C2 30Gs.
Interesting the inner cylinder extension (≈5mm) mod proposal, I wonder who would be willing to craft such a piece for a reasonable cost (preferably in copper). It is a bit @#$% to see how the torch designers didn't realized this beforehand. 
Cheers 
Original post date: Fri, 09/15/2017 - 22:22. Edited for a lil fix.
Doesn’t it emit some IR (or near-IR) as a a part of the light output?
I have felt an IR heat out of the front of lights on medium power, where the Noctigon and host are fairly cool.
If so, it would completely skew the reading. (also, I’ve seen approx. 125C as the upper measurement limit on some IR thermometers)
Some infra-red output, agnelucio? Don't really know, but if that is true then maybe I can step up my 3000K emitter power a bit higher without much of a worry… 
The thermometer is an old high end unit, not sure if its user manual is buried in my user manuals' drawer but I am pretty sure it measures way beyond 125°C, I could measure 210°C in my smoky electric frier just last night. It even has a laser for aiming.
Cheers :-)
So far as I know, the best way to measure LED temp accurately is to put a thermocouple/thermistor based thermometer probe on the central solder pad of the LED (some MCPCBs eg Noctigon even have some exposed pad for this purpose), measure the temperature, measure the power going to the LED, calculate the temperature drop across the junction-to-pad substrate using the resistance given in the datasheet for that LED, then add that drop to your measured value, and finally you would know the junction temperature for that power level.
Simple! 
I have what is probably a simple question, it seems that by my reading of the TI datasheet, that this should be ok. I have a Mag 4D that runs with Ni-MH batteries, when fully charged read around 1.4v each. I know most of you are running off 1 Li-ion cell, so would never see a 5.6v into the driver, but it seems like it would be safe to do this, and run an XHP70 at 6V. Any ideas?
With a freshly charged 4S bigass NiMH set the input voltage may result a bit high for the low mode to be regulated on the H1-A, wildstar87, but it should work. The low voltage cutoff is at 3V, this would result to an average of 0.75V/cell. Not bad. 
Cheers ^:)
P.S.: Jensen567, how good are the now relatively popular LTC3780 CC/CV modules? They sure look nice…
H1-A would be fine with a 4S Ni-MH input, but as barkuti said the low mode may not be well regulated (it will likely be brighter than expected). Nothing will be hurt though.
Barkuti, the LTC3780 modules are quite nice, I have 2 of them I use as an LFP charger for retrofit Ni-Cd drill packs. Not positive how they would work for your cordless area light as I don’t think I have tried that specific combination of input/output, but I imagine it should handle 1S input at 10A no problem.
So I can now confirm that H2-C can be modded to change the output voltage and LVP value. LVP mod could also work for H1-A and KX70. More details in my scratch build thread, I will probably repost here later.
Thanks for sharing your findings!
Updated OP with test results from an H2-C configured as I used in my scratch build. This driver is a champ! Efficiency on the modes that matter is basically 90+ up until the very bottom of the discharge. Regulation is also maintained right up to the end of discharge.
Numbers for turbo mode are slightly dubious, as my electronic load showed a voltage higher than I saw from the meter measuring at the board, and the load number was bouncing around while the meter number was solid. The rest of the modes both had solid voltage with the load showing lower than at the board as expected, so those I trust completely.
This is to attract knowledgeable folks on this matter: Serial battery charging with in series TP4056 modules?
Cheers :-)
I managed to greatly improve the KX70 driver this morning. It now has constant regulation through the entire discharge as well as actual mode spacing.
To get the driver to regulate through the entire discharge all I did was place an SOT-23 2.8V LDO in the blue circle. Stock this is just bypassed with a 0-ohm jumper link. I used the KD “528” LDO that I took off of an FX-35 driver, but almost any 2.5V to 2.8V output LDO in SOT-23 package will work here as long as it supports high enough input voltage.
To get mode spacing back I removed the capacitor and resistor in the purple circle, and replaced that capacitor wirh the capacitor in the green circle. Another option would be to just remove the purple circle capacitor and then bypass the resistor with wire or a solder bridge. End result is the same either way. I will re-run the output tests later to show the improvement in mode spacing.
Also updated the OP, but here is the KX70 test results with the LDO and Filter cap mods. Fantastic driver now, no complaints at all. I plan to duplicate this setup on the driver in my JKK36 host which should make that light much more useable.
The KX70 seems great with these mods :+1: The only drawback is the diameter.
Can the H1-A be modded in a similar fashion?