^ What he said 
Cheers David
Ah dummy pass through carrier fillers, smart!
Does anybody knows what kind of max amps we can expect from the original driver (modded or not) on a xhp70(.2) ?
I’m pretty sure the xhp35 on mine wont stay long, i’ll transform the GT into my dream K60 on steroids.
Standard the driver puts out 2A on high and 2.5 on turbo, that should stay the same for all 12v leds.
I did read somewhere in the group-buy thread that it can be modded to 5A with cooling.
If I am wrong will someone please correct me 
Cheers David
IIRC, 5A is indeed its limit. It definitely needs a good thermal connection to the flashlight body. Might even need more heat sinking at that power level.
What about a hardcore mod? (spacer needed).
- seven reflectors: http://kaidomain.com/p/S026180.42mm-x-57mm-SMO-Aluminum-Reflector
- 3P xhp-70.2 (12v configuration each) wired in paralel with 4s dedomed xp-g2.
- FET driver.
Only question, is there a 4s battery capable FET driver with electronic swhitch configuration for this mod?
A dded XHP35 is a must have for a modded GT, if XHP35 based ofc:at least 15, ( even 20% possible) bump in candelas
The Miller : shall we have a spare drivers for that light? Or at least an Oshpark PCB option
Like that idea,Or how about 7 XHP-35? 14,000 to 17,500+ throwy lumens? :nerd_face:
Ready and waiting……
De-Domed XHP35’s E2’s E4’s, XPL W2’s, Old School 6.3amp XP-G2 and even a DD 70.2 just for kicks!
3amp 4S Linear Drivers are ready too, so contact boards will be needed or just wipe the stock one clean!
How about spare reflectors for purchase also!
You probably don’t want that deep reflector.
Deep reflectors are not what you hope for.
You get a very wide and bright corona and not much throw.
NarsilM with TA LDO drivers just running the FET should work well
just need to figure out the resistor value for 4S to get proper LVP
Jerommel: correct me if I am wrong, but as far as I know throw depends on reflectors diameter. A taller reflector makes the hotspot to be smaller (this is the reason for choosing them).
Lexel: But this driver needs to be build and programed. Don’t have the skills for the firmware stuff.
Think the driver board can be ordered at oshpark already.
If not, it will be so and a list of components will be posted in the GT thread at a later time
It doesn’t.
It’s because the shorter reflector is a section of a larger parabola, so the focal distance is bigger with a shorter reflector, or in other words, the LED is relatively smaller in relation to the parabola with a shorter reflector, resulting in a tighter beam.
Also, the amount of extra light that is reflected with a tall reflector is not that significant.
You will see that the best throwers have a shorter reflector.
They are never taller than they are wide, usually they are a little shorter than the width.
The surface area of a reflector (as seen from the hotspot, so a 2D circle) determines the throw for a given lightsource. It doesn’t matter how big or small the hotspot actually is. Only the luminous intensity matters (measured in candela or “lux@1m”).
The area of a reflector is mainly influenced by the diameter of the large opening because area_of_circle = radius^2 x pi. For a given outer diameter changing the depth of a reflector does have a small effect because the smaller hole at the bottom must get smaller. Thus the area is a bit larger, but it’s a very small effect.
Deeper reflectors do change the shape of the beam. The hotspot becomes smaller, the corona bigger, and the spill angle smaller compared to shallower reflectors of the same diameter.
Thanks both for the explanation. :+1:
The throw is determined by both the frontal surface area and the focal distance (the distance between the LED and the reflector surface)
I would say it is determined by the size of the parabola actually, the bigger the parabola (in relation to the LED) the better.
Depth doesn’t make too much of a difference, that’s why we see reflectors are usually shorter than their width.
Obviously the intensity will be higher with a tighter beam = smaller hotspot.
Have a look at how little more light is reflected when you make the reflector deeper:
(dark red is typical flashlight proportions)
You have to add a lot of depth to catch an additional 5° from the LED, it’s not worth it.
But, it wouldn’t add too much width in all, so you could go for square proportions (width = depth)
But let me say this:
I have a light with a very deep reflector, which i bought when i thought it would be good for throw.
Well, it isn’t good for throw.
The base of that reflector is considerably narrower than a short one of the same diameter, resulting in a weak beam with a corona as big as the spill.
I guess this could be useful in certain circumstances, but it mainly adds length to the head of the flashlight and not throw.
Nope, intensity is not higher with a tighter beam. A very common misconception.
Throw (cd) = luminance_of_lightsource (cd/mm^2) x surface_area_of_reflector_as_seen_from_hotspot (mm^2)
It’s that simple! You can actually calculate the luminous intensity and thus throw of a light before building it. It’s very accurate as long as your base values are accurate.
Of course this has nothing to do with how practical the beam of a light is or how big the spot is etc. Only the pure throw can be easily calculated.
Also see Dr.Jones explanation here: Flashlight Optics - Dome, Dedoming and Throw
So it’s not that shallower reflector throws better. For the given diameter, deeper throws better. For the given length, shallower throws better. For the given volume there’s some sweet spot which depends on the LED used.
I ordered this lens today for my GT.
http://www.optolife.com/singlet_lens/A037.html
I want to kick the Optofire´s ass
