XM-L T6 1x 14500/AA

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uncajesse
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XM-L T6 1x 14500/AA

Waiting for an XM-L T6 1x 14500/AA light to come up, with a driver that pulls about 1.5 amps on high from a good 14500.

No strobes or SOS, with medium for indoor use (like 25%), and low = moonlight (like 6 lumens).  Or maybe a very usable variable output.  Current limited high mode, with Current+PWM on low modes fast enough to not be visible, and slow enough not to make noise.  Memory that just works, and of course the driver should be very efficient on the lower PWM modes.

Forward clicky if it works with the driver.  Decently floody OP reflector for indoor use, hotspot maybe 40% of the spill size.  T6061, HAIII, IPX8.  Threaded after annodizing (way better heat transfer).

Is that too much to ask? Foot in mouth

jekostas
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Want it should do your taxes and walk your dog as well?

uncajesse
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Har har.

There are already lights that basically match this, just not with an XM-L (and appropriate driver & reflector).

pipopopo
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@ 1.5 A (max) a XP-G can do all of this with even more trow

Kokopelli
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A well driven XP-G R5 is worth considering. I built myself a 1400mA 16 mode R5 Ultrafire A10B and more than pleased with it. I had XM-L's at hand, and could put in a 2800mA driver but that would give me just more heat, and more flood.

 

arenat
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The driver which is close to that, not moon mode just a 20 lumen low , is AK101 with an added amc7135 you get  1,4 A 330 mA 50 ma, strangely when you ad amc7135 the medium mode don't grow proportionally as expected , even decrease it, with 2 amc added 5 total you get 1,75 A 350 ma 55 ma...

Last Monday I mod one Romisen RC-G2 with the 5 one which gave around 550 Lumen 130 Lumen 20 Lumen , a lot of light but since that was the only emitter at hand two hours later stripped all again and the winner was the UF P10 with an AK105 8 regulators...2,8 A 980ma 60 mA

uncajesse
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pipopopo wrote:
@ 1.5 A (max) a XP-G can do all of this with even more trow

With less efficiency, hence less output, and I want it for everyday use so throw is less of a factor than flood.  My EDC right now is the new TrustFire R5-A3 (with the 0.15A low mode) which throws a lot more than I need for EDC.  More flood would be just as welcomed as a higher output with the same heat and same draw from batteries as what I have now.

Also I personally am not assuming that XM-L has less throw than an XP-G for the same wattage, since the XP-G in a small reflector doesn't have great throw anyways, and XM-L is more effecient especially around 1.5A where it's at half its rated power and still really high on the efficiency curve.  The XP-G at 1.5A is at the high end of its power handling, and well into where the efficiency starts to drop off.

I'm comparing my R5-A3 with fresh "flames" right now on high (1.7A), to my KD C8 w/ fresh flames on medium (1.1A), with a ceiling bounce...  and the XM-L is *still* a tad brighter.


However...  This does ignore one important aspect that I haven't seen discussed anywhere yet...  The psycho-visual effect of pulse width modulation upon subjective brightness.  Like when you're at a movie, and each frame blends into the other frames without flickering, even though the shutter is only open for a fraction of 1/24th of a second. Smile This *does* increase the subjective average brightness!!!

This is something I was going to talk to SPAMBOT about, since he seemed interested in efficiency, and to see/search if any research has been done on this, and then post a well formed write up about it for you guys.  And how to accurately measure it as close as possible to the subjective brightness experienced by the average subject.  Smile  But for now, it seemed important to bring up here, since I was just comparing a current & PWM mode with each other.

Personally I think the subjective brightness (and therefore battery life) of any current regulated modes can be optimized with pulse width modulation being done at a frequency that makes the most use of this particular psycho-visual phenomenon.  A driver that maximises the balance between peak current and pulse width, essentially.  For starters, dropping the peak current drawn to the most efficient spot for a particular LED, and widening the pulse width to compensate for the average amps drawn, should cause the light to be brighter with the same power used.

This should also have some effect on the way the batteries work too, since we're not using super conductive batteries the current will be drawn differently, and hence they have *some* inductance & capacitance, in addition to also having a base resonance and harmonics in which standing waves can be built up (but making use of that is way more advanced than we'll probably ever see in a flashlight).  Mainly the effect would be in reducing the peak current draw during each pulse. Smile

Third and final thing that I would like to explore along those lines is the effect that different frequencies of PWM have on the LED itself, from kHz to gHz.

But I'm not ready to get into any of that yet, before I get scientific ammo.  I just thought, in the name of science, that I should explain this for people that haven't thought about it yet, that it probably did bias my comparison.  If it biased it anywhere near the 63% difference in current pulled (to which the XP-G had the advantage), I couldn't tell ya.  Yet.  Smile


Anyways...  Silly  back on topic.  An XM-L is quite a bit more efficient than an XP-G @ 1.5A.  More output & less heat.  (plus the heat is spread over a larger die, so it should be less prone to heat-induced efficiency reduction for the same overall heat output)  Combined with a reflector designed for it, and that alone with current driver designs is still enough to make me want to upgrade.

Kokopelli
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If you don't need much throw (well even a P60 XML is like pure flood for me) then an XM-L should be more efficient (not due to lumens/watt rate as it looks like XP-G and XM-L look very close, and even XP-G could be somewhat higher) because of it's mid range operation and lower heat. But my XM-L is greenish while XP-G is pure white, and I like XP-G's slight throwier beam than an XM-L's pure flood. Even a C8 can't really focus an XM-L led.

uncajesse
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Kokopelli wrote:
Even a C8 can't really focus an XM-L led.

I got about as close as I think I can get with mine, considering it's an OP reflector.  With the ability to see what's in people's houses from 2 blocks away, it's "too bright" to use around town on high. Cool So yeah... I think I'm definitely looking for something even more floody than my current EDC for indoor use to fill the other half of what I want.

I do agree with you about the beam color, but in practice I haven't cared.  I dunno if mine is less green or more green or what.  One "drawback" to the OP reflector in mine is the green light is the most distorted light (less surface per degree off axis) so it ends up quite a bit larger than it would be with an SMO.  But it's also less defined, so I don't get any weird green ring per say, just a glow.

sixty545
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uncajesse wrote:

Third and final thing that I would like to explore along those lines is the effect that different frequencies of PWM have on the LED itself, from kHz to gHz.

But I'm not ready to get into any of that yet, before I get scientific ammo.

Here is something to start with although it is mainly about single pulses. Perhaps there is something in the references.