+1
I’m no expert here but have a few lights of all size and although i may have not argued as clearly as djozz, i would have said that this kind of small light should not run much higher then 600 lumens because of heat dissipation - as of today. The 3k/4k lumens extravaganza is just that, a quick burst if need be but only for a few seconds. No magic involved here.
Now, hopefully, one day in the not too distant future… we may have more efficient leds that produce very little heat… and this kind of minor miracle may last much longer then we dare imagine. Pure light, no heat, that would be intense. Could you have imagined a D4 just five years ago? Can’t wait to be ten years older! :smiling_imp:
imo No, because the light already has built in protection, read post #1:
About 30 seconds at which point the light drops to 10% output…
Look at the post below by CRX… it depends partly on what thermal regulation setting is being used
See post 958 below, to get some idea. It has been suggested that 600 lumens might hold steady. afaikt there is no way to set the light to 600 lumens, or any other specific lumen level, unless you have a light meter.
you Can set to a NoPWM mode of about 150 lumens:
Post #1
Hmm… So, if you start at a lower level, what is the highest output it can sustain for a couple minutes? 600 Lumens sounds low? So after two minutes my Zebralight SC600 II would be brighter? I see H2 on the Zebra is about 670 listed output, so maybe around that level?
Yes, I know Efest 18500. However, compared to 18650 vtc6/30q/GA & 18350 Aspire; I expect a good 18500 size battery will do High Discharge: 10~15A, Capacity: 1300~1500 mAh.
Agro, all your notes are confusing.
If you have implementation ideas perhaps you should just offer new code, maybe then a simple reflash would allow others to sample your idea of perfection?
I know several here have already done due diligence to get the D4 to where it is today, I like mine and will be the first to admit I’m still playing with it and learning.
20 amps running through this small light body, in the palm of my hand… Should i be worried?
How much of a magnetic field would that produce? Would it affect a compass up close?… How about PWM induced field variations?
Could you explain what do you find confusing about them?
I would be very happy to do it. Typically these are not major changes. But I have no hardware to be able to reflash the light myself, so I can’t check my changes.
They did amazing work. But there are (mostly trival) wrinkles here and there and I do what I can to smooth them out - give feedback to the makers.
If you are, do you have any explanation why mine steps down in under ten seconds using the vtc6 and lower ambient temperature than you? Should I check if the thermal paste is badly applied on mine?
Btw, I haven’t fiddled with the temperature limit, so it’s still at 45 degrees.
Just did a little test underwhile browsing BLF. I put a fresh 30Q cell in my D4 and using my sphere I set the output at 550 lumen (my D4 now has 3500K 90CRI 219C’s so it is comparable to the stock 219C’s at about 600 lumen). I started hand-cooling the light. I must say I had a rough time, I had to swap hands every minute and it was still an unpleasant temperature, but it really was sustainable, after 12 minutes I decided that I could just go on like that and stopped the test. The output had dropped to 500 lumen then.
I did it again (start at 550 lumen) with a more depleted 30Q (3.7 V at start) and now it was a bit easier, but not much.
So yes, 600 lumen as the maximum sustainable temperature inside at room temperature seems about right. But without hand-cooling it will be lower (TK’s temperature feedback makes it about 300/400 lumen, as read in CRX’s data)
It were 4 - x mm longer and had a heavy shelf behind the emitter? (would a longer light be a problem?)
Is this telling us that this light is a great candidate for real cooling fins?
Not an expert here but are there other drives that can run the light with less heat (or brighter for the same heat) thermal efficiency?
I understand the meteor m43 has a more efficient driver arrangement, could something like that be a “good” option for the D4?
And My personal soap box, I say we need a “just right” sized light between the 4x18650 MeteorM43 and the 16340-18650 D4.
I’m thinking 26650 with 6-9 emitters. How much meat and fins and with what type of driver should it be specked with?
“Basically, thermal regulation is rather unpleasantly like trying to steer a fast-moving cow around a hairpin turn on an icy race track. While wearing someone else’s glasses.”
I have a dumb question/idea.
If it is so hard to manage (thermal management of the X where the sensor is placed near the emitter) and as the gating interaction seems to be the ability to hand hold the light (as opposed to frying the emitter). What would happen if instead we just thermally managed the body/head of the light.
When Light gets X hot (subjective to the hand) then use that temp as the target temp. My hunch is this will make the management and both easier and more accurate.
Then all we have to do is try to steer a fast-moving cow period and (“around a hairpin turn on an icy race track. While wearing someone else’s glasses.”) goes away.
Hard to tell what’s optimal, but that is definitely an option.
What it DOES NEED is active cooling of some sort, so it can maintain an output of at least 2000+ lumens indefinitely.
Make it as small as possible and don’t forget high CRI.
I really like your idea. I always though that 3x18650 fit much more comfortably in the hand. The number of emitter I leave it to the experts, but 3x3 is 9. Sort of like an in-out burger (for those who don’t know their best seller is a “double-double”) so maybe a triple triple is what is needed for the Goldy Lux light. (pun intended)
I have always thought that 4x 18650 light were just a bit large to actually want to carry (sure it can be done) but out of our flashlight actual carry minutes what percentage is from 4x18650 lights? My hunch is it is out in the long tail of the bell curve.
Not my idea Mr. Ronin. This light will see daylight soon. How soon, that we don’t know yet. This light is the D7, and will be presented after the D1S IIRC. 3x18650 with 7 emitters it is, yay. :partying_face:
Better quality, (DQG) seems to have issues from what Ive read.
Why so small, just a bit longer and maybe real cooling fins and the light does not need to be throttled back.
more emitter choices, it just kills me to buy a new light and then spend a bunch of money and effort to go and change the emitters. better to pay for that up front but only once.
So yes A DQG but with Zebralight/Hank Build quality. Super well thought out (and responsive revisions) TK software not trying to be smallest (why do that?) I say shoot for most usable aka the light we grab whose use falls under the big part of the bell curve. And while I’m at it, in a real sand/earth tone (not gold or almost gold) color.
I see you know how to say the right things to the boys but how do I know your not just a tease?
Like they say, photos or it did not happen. But If Hank said that a D7 was in the works, now that would be interesting. and is the rumor of 3x18650 settled or is a more moderate/carryable 26650 light possible (Or is that a D6) Part of my reasoning for the 26650 is greater size/weight flexibility. With a sleeve or different tube (yaaa custom tubes like the D4) we can have a light that could run 1x 26650, 18650, 18350, 18500, 14500, 16430.
So the light gets designed with just “enough” mass/fins (seems like the D4 might be a nearly perfect light but short on mass/fins to really use the HP under the hood) and then choose your power/weight configuration of the day.
but how do I know your not just a tease?