Flashlight concept #1 - Multi-emitter tint-ramp light

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Lux-Perpetua
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Flashlight concept #1 - Multi-emitter tint-ramp light

Hello everyone,

I did some thinking on new flashlight concepts and mostly about those things we seem to miss in some good but not perfect flashlights, e.g. good thermal management, good heat transfer, efficient drivers, convenient user interface and interesting LED configurations. With Fireflies' E07 and ROT66 V2, Mateminco's MT07 and Sofirn's IF25 in mind I wrote down a rough concept. I would appreciate any feedback on this, especially if this is something reasonable and feasible in your opinion.

 

Edited by: Lux-Perpetua on 11/05/2019 - 04:44
Yokiamy
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I like the tint mix version!
Would it be possible to change the preferred tint by giving the preferred LED’s more or less current ?

  BLF

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In this size that copper head makes it really massive, not a light that I would carry with me. The tint-mixing version is nice, I think it is a pity that Sofirn went for their own tint-mixing version instead of Anduril.

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Yokiamy wrote:
I like the tint mix version! Would it be possible to change the preferred tint by giving the preferred LED's more or less current ?

Yes, that's the plan. Adjusting the current for WW and NW LEDs will change the mixed tint.

djozz wrote:
In this size that copper head makes it really massive, not a light that I would carry with me. The tint-mixing version is nice, I think it is a pity that Sofirn went for their own tint-mixing version instead of Anduril.

That's a good point. Maybe they™ could use a press-fitted copper pill (like Nightwatch IRA) instead of a solid copper head and/or solder the MCPCB to the pill which should result in better thermal transfer. I wish LEDIL offered a partially wide beam frosted and partially clear narrow spot optic. This would give us a whole bunch of new ideas like 3 emitters for throw, 3 emitters for flood and a wide beam frosted auxiliary light in the middle (it does not necessarily need to be deep red Wink ).

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For me an EDC light would have to have a head width of 35mm max. It can be a tiny bit more but depends on the head design. I think 7 LH531Ds might be too floody. Four would be better IMO.
Here’s some things I would like to see

Decent throw 25+ kcd for high cri version. More would be nice but the LH351Ds are domed so I don’t think it’s possible.

Tailstanding ability

Strike bezel so it’s harder to leave on by accident

Three selectable colour aux LEDs if there’s space (red, purple, orange)

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Lux-Perpetua wrote:

This would give us a whole bunch of new ideas like 3 emitters for throw, 3 emitters for flood and a wide beam frosted auxiliary light in the middle (it does not necessarily need to be deep red Wink ).


Yes, two of them WW, one CW. That would compensate for the lesser efficiency of WW LEDs.

Lux, when to expect this true threedimensional (brightness, tint, beam) flashlight exactly? Crazy

Almost forgot: Add this CCD element to autoadjust WB Cool .

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I just added the "USB-C port in thread section" feature. How could I've forgotten that? Big Smile

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1.
Solid copper head is good for sustained performance but bad for turbo. It conducts heat away so well that it keeps the LED – and (what matters more) the LED surroundings much cooler than other materials would. Since they are much cooler they fail to store much heat.
For this reason solid copper lights tend to overheat faster than aluminum ones despite the fact that they weigh 3 times as much.

And thermal transfer improvement is marginal anyway.

2.
I really like 7-up optics because they make good use of the frontal area. Almost like 1-up…but unlike 1-up they are way flatter.

3.
I never use red lights, so for me the extra red LED would be a waste. Especially on a thrower. But if you like it – why not.

4.
Tint mixing – I’m a big fan of it

5.
Having a variant with 3535 LEDs and another with a mix of 3030 and 3535 would require 2 different MCPCBs. I’m not sure if that’s a big deal though.

6.
I think White Flat 1 mm² would make a better thrower choice. For ~45 mm head 12 mm² (let alone 14 mm²) is quite a lot. Very short turbo and actually quite floody beam. 7x KW CULNM1.TG (aka Boost HL) would truly rock.

7.
As usually with dual switch lights – I believe it’s worthwhile to give user a choice whether they want the tail clicky or just a flat cap.

8.
A Powerbank capability is a boon for any rechargable light with reasonable battery size

9.
A boost driver capable of driving 12 mm² White Flats? Not easy. Not compact. Not cheap. But doable.

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Agro wrote:
1.
Solid copper head is good for sustained performance but bad for turbo. It conducts heat away so well that it keeps the LED – and (what matters more) the LED surroundings much cooler than other materials would. Since they are much cooler they fail to store much heat.
For this reason solid copper lights tend to overheat faster than aluminum ones despite the fact that they weigh 3 times as much.

And thermal transfer improvement is marginal anyway.

4.
Tint mixing – I’m a big fan of it

5.
Having a variant with 3535 LEDs and another with a mix of 3030 and 3535 would require 2 different MCPCBs. I’m not sure if that’s a big deal though.

6.
I think White Flat 1 mm² would make a better thrower choice. For ~45 mm head 12 mm² (let alone 14 mm²) is quite a lot. Very short turbo and actually quite floody beam. 7x KW CULNM1.TG (aka Boost HL) would truly rock.

1. you are talking quite nonsense, just because Copper conducts 3 times better than Aluminum it will be completely even tending to be even cooler, why?

Just check a Cree XPL here at 3A
let’s assume LED runs 120°C on aluminum and 100°C on copper
- the amount of power with a regulated driver gets a bit higher as the LED voltage increases 0.04V*3A=0.12W more
- but also the photon conversion is more efficient almost 50 lumens more at 350lm=1W 49lm÷350lm/W= 0.14W

On an unregulated DD driver your observations are also not true, why?
With a lower temperature the LED voltage is higher so the light draws less current

copper lights may feel hotter as they heat up more evenly through the whole body

4. I think tint mixing is not so much-needed on a light
Also why is 351D 2700K so much less efficient?

5. I am sure such a MCPCB with both emitters can be made
I can see if that would also allow an aux board probably the positions of the main LED wires soldered is critical here to get a symetrical pattern

6. agreed

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Lexel wrote:
Agro wrote:
1.
Solid copper head is good for sustained performance but bad for turbo. It conducts heat away so well that it keeps the LED – and (what matters more) the LED surroundings much cooler than other materials would. Since they are much cooler they fail to store much heat.
For this reason solid copper lights tend to overheat faster than aluminum ones despite the fact that they weigh 3 times as much.

And thermal transfer improvement is marginal anyway.

4.
Tint mixing – I’m a big fan of it

5.
Having a variant with 3535 LEDs and another with a mix of 3030 and 3535 would require 2 different MCPCBs. I’m not sure if that’s a big deal though.

6.
I think White Flat 1 mm² would make a better thrower choice. For ~45 mm head 12 mm² (let alone 14 mm²) is quite a lot. Very short turbo and actually quite floody beam. 7x KW CULNM1.TG (aka Boost HL) would truly rock.

1. you are talking quite nonsense, just because Copper conducts 3 times better than Aluminum it will be completely even tending to be even cooler, why?

Just check a Cree XPL here at 3A
let’s assume LED runs 120°C on aluminum and 100°C on copper
- the amount of power with a regulated driver gets a bit higher as the LED voltage increases 0.04V*3A=0.12W more
- but also the photon conversion is more efficient almost 50 lumens more at 350lm=1W 49lm÷350lm/W= 0.14W


So…roughly 0.14-0.12 = 0.02W or 0.2% more, right?

Lexel wrote:
On an unregulated DD driver your observations are also not true, why?
With a lower temperature the LED voltage is higher so the light draws less current

Yes, more than 0.2% with FET.

Now the amount of heat stored is the integral of (temperature hike) * (volumetric specific heat) over volume.
Assuming constant surface temperature of 60C (that’s the moment when the light needs to step down) and ambient temperature of 25C.
Temperature difference between surface and near the led is inversely proportional to thermal conductivity.
With 100C for copper we would have ~160C for 6061 alu, regardless of head size shape etc. Yeah, that 100C is likely too large. I think 80C copper and 130C alu would be more like it, though I am not sure about it really.
This gives temperature hike over ambient of ~55C for copper and ~105C for alu. Adjusted for difference in volumetric specific heat (copper is better), with these parameters alu would store ~33% more heat near the LED. Now, near the surface it would be the opposite, both have the same temperature, alu stores about 31% less. But then the temperature at the hottest point of the surface is much smaller; heat storage near the LED is more important. At the cooler points of the surface the difference will be larger in favour of copper. But then – the amount of heat stored there is minimal.

Lexel wrote:
copper lights may feel hotter as they heat up more evenly through the whole body

In practice – through the whole head. And not much elsewhere. Facepalm

EDIT:
Wrong, 0.02W is not ~0.2% but more like 0.3% because energy consumed != energy dissipated as heat.

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Agro wrote:

Yes, more than 0.2% with FET.

Now the amount of heat stored is the integral of (temperature hike) * (volumetric specific heat) over volume.
Assuming constant surface temperature of 60C (that’s the moment when the light needs to step down) and ambient temperature of 25C.
Temperature difference between surface and near the led is inversely proportional to thermal conductivity.
With 100C for copper we would have ~160C for 6061 alu, regardless of head size shape etc. Yeah, that 100C is likely too large. I think 80C copper and 130C alu would be more like it, though I am not sure about it really.
This gives temperature hike over ambient of ~55C for copper and ~105C for alu. Adjusted for difference in volumetric specific heat (copper is better), with these parameters alu would store ~33% more heat near the LED. Now, near the surface it would be the opposite, both have the same temperature, alu stores about 31% less. But then the temperature at the hottest point of the surface is much smaller; heat storage near the LED is more important. At the cooler points of the surface the difference will be larger in favour of copper. But then – the amount of heat stored there is minimal.

Lexel wrote:
copper lights may feel hotter as they heat up more evenly through the whole body
In practice – through the whole head. And not much elsewhere. Facepalm

1.
You do the math wrong, we already have a thick copper MCPCB which reduced the temperature difference between a copper or aluminum head
Ask any here in forums why we don’t want to use aluminum MCPCBs even if they are DTP, the heat conduction is absolutely critical to keep the LED temperature low

Nobody wants to store the heat near the LED, the cooler it runs the better its photon conversion is, so people asked manufactures for thicker shelves on the BLF lights to move the heat faster away and give more heat buffer

I have done several thermal imaging videos of aluminum heads, the heat from the hottest to the coldest spot is minimal as the conduction of heat is already very good on flashlights with a thick shelf and thick walls

2.
Your 0.2% on DD drivers is also wrong math
look on a Samsung 30Q battery for example and look how much 40mV voltage difference between a hot and cold LED result in current change
I did here the graphs between 5 and 7A and on average I would say about 40mV difference

so your 0.2% I don’t know how you calculate that number results in my calculation for 40% current change without any resistance added
so lets take bypassed springs and switch with 50mOhms and driver and LED leads also 50mOhms
40% change on 16mOhm of the 30Q cells, now lets do the math with all resistances I get 5.5% less current on DD light just by 20°C lower LED temperature

3.
I mean a 100% copper light with copper tube, most people touch a hot rod light only on the tube, the better it conducts heat the more the human heat sink plays a role

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Lexel wrote:
Agro wrote:
1. Solid copper head is good for sustained performance but bad for turbo. It conducts heat away so well that it keeps the LED - and (what matters more) the LED surroundings much cooler than other materials would. Since they are much cooler they fail to store much heat. For this reason solid copper lights tend to overheat faster than aluminum ones despite the fact that they weigh 3 times as much. And thermal transfer improvement is marginal anyway. 4. Tint mixing - I'm a big fan of it 5. Having a variant with 3535 LEDs and another with a mix of 3030 and 3535 would require 2 different MCPCBs. I'm not sure if that's a big deal though. 6. I think White Flat 1 mm² would make a better thrower choice. For ~45 mm head 12 mm² (let alone 14 mm²) is quite a lot. Very short turbo and actually quite floody beam. 7x KW CULNM1.TG (aka Boost HL) would truly rock.
1. you are talking quite nonsense, just because Copper conducts 3 times better than Aluminum it will be completely even tending to be even cooler, why? Just check a Cree XPL "here":http://pct.cree.com/dt/index.html at 3A let's assume LED runs 120°C on aluminum and 100°C on copper - the amount of power with a regulated driver gets a bit higher as the LED voltage increases 0.04V*3A=0.12W more - but also the photon conversion is more efficient almost 50 lumens more at 350lm=1W 49lm÷350lm/W= 0.14W !{width:50%}http://www.metronixlaser.de/bilder/flashlight/XPL_3A.png! On an unregulated DD driver your observations are also not true, why? With a lower temperature the LED voltage is higher so the light draws less current copper lights may feel hotter as they heat up more evenly through the whole body 4. I think tint mixing is not so much-needed on a light Also why is 351D 2700K so much less efficient? 5. I am sure such a MCPCB with both emitters can be made I can see if that would also allow an aux board probably the positions of the main LED wires soldered is critical here to get a symetrical pattern 6. agreed

 

So, a press-fitted copper pill and/or soldered MCPCB could probably be more efficient in terms of weight, thermal conductivity and dissipation as well as being more cost-effective?

Using a full copper body would definitely increase both weight and cost dramatically. I was hoping to match the best of three worlds (Titanium for a sturdy bezel, Copper for best thermal transfer, Aluminum for best and fastest heat spreading/dissipation alongside the battery tube with the benefit of less weight).

The idea about tint mixing originates from Sofirn's IF25 and the LT1 lantern. Basically, I would like to enable every customer to choose his/her favorite tint between warmwhite and neutralwhite. We could also go up to 5.700K 90CRI - no big deal. There might be certain situations when people like using neutralwhite (outdoor in summer) but also want to change to warmwhite (outdoor in winter with highly reflective snow/iced surfaces or when inside) with the same flashlight. If tint-mix is not an option we could still mix LH351D 2.700K 90CRI with 5.700K 90CRI to get rid of any greenish tintshift and drive the mixed tint below the BBL resulting in a rosy tint pattern somewhere around 4.000K. Just thinking...

Why is 2.700K so much less efficient? Because most (all?) warmwhite emitters seem to have less efficiency than coldwhite emitters. I do not have accurate numbers for LH351D 2.700K 90CRI but I quickly translated the reduced output by the expected loss in efficiency. We may get a bit more output here but I wanted to keep the numbers conservatively calculated.

If multi-footprint MCPCBs are feasible, how about replacing the inner XP-E2 deep red by an Osram White Flat KW CSLNM1.TG 1mm²? This would give us a flashlight with both flood (6x LH351D) and throw (1x Osram White Flat 1mm²).

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Lux-Perpetua wrote:

 


So, a press-fitted copper pill and/or soldered MCPCB could probably be more efficient in terms of weight, thermal conduct and dissipation as well as being more cost-effective?


The idea about tint mixing originates from Sofirn’s IF25 and the LT1 lantern. Basically, I would like to enable every customer to choose his/her favorite tint between warmwhite and neutralwhite. We could also go up to 5.700K 90CRI – no big deal. There might be certain situations when people like using neutralwhite (outdoor in summer) but also want to change to warmwhite (outdoor in winter with highly reflective snow/iced surfaces or when inside) with the same flashlight. If tint-mix is not an option we could still mix LH351D 2.700K 90CRI with 5.700K 90CRI to get rid of any greenish tintshift and drive the mixed tint below the BBL resulting in a rosy tint pattern somewhere around 4.000K. Just thinking…


Why is 2.700K so much less efficient? Because most (all?) warmwhite emitters seem to have less efficiency than coldwhite emitters. I do not have accurate numbers for LH351D 2.700K 90CRI but I quickly translated the reduced output by the expected loss in efficiency. We may get a bit more output here but I wanted to keep the numbers conservatively calculated.


If multi-footprint MCPCBs are feasible, how about replacing the inner XP-E2 deep red by an Osram White Flat KW CSLNM1.TG 1mm²? This would give us a flashlight with both flood (6x LH351D) and throw (1x Osram White Flat 1mm²).

Looking on Digikey as a source for LH351Ds
I get 2700K CRI90 310 and 330LM binnings
for 5000K CRI90 390-410 binnings

so 4000lm for 5K
and 3200lm for 2.7K

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Lux-Perpetua wrote:

 


So, a press-fitted copper pill and/or soldered MCPCB could probably be more efficient in terms of weight, thermal conduct and dissipation as well as being more cost-effective?


The idea about tint mixing originates from Sofirn’s IF25 and the LT1 lantern. Basically, I would like to enable every customer to choose his/her favorite tint between warmwhite and neutralwhite. We could also go up to 5.700K 90CRI – no big deal. There might be certain situations when people like using neutralwhite (outdoor in summer) but also want to change to warmwhite (outdoor in winter with highly reflective snow/iced surfaces or when inside) with the same flashlight. If tint-mix is not an option we could still mix LH351D 2.700K 90CRI with 5.700K 90CRI to get rid of any greenish tintshift and drive the mixed tint below the BBL resulting in a rosy tint pattern somewhere around 4.000K. Just thinking…


Why is 2.700K so much less efficient? Because most (all?) warmwhite emitters seem to have less efficiency than coldwhite emitters. I do not have accurate numbers for LH351D 2.700K 90CRI but I quickly translated the reduced output by the expected loss in efficiency. We may get a bit more output here but I wanted to keep the numbers conservatively calculated.


If multi-footprint MCPCBs are feasible, how about replacing the inner XP-E2 deep red by an Osram White Flat KW CSLNM1.TG 1mm²? This would give us a flashlight with both flood (6x LH351D) and throw (1x Osram White Flat 1mm²).

Looking on Digikey as a source for LH351Ds
I get 2700K CRI90 310 and 330LM binnings
for 5000K CRI90 390-410 binnings

so 4000lm for 5K
and 3200lm for 2.7K

also why not simply compensate the lumens in the firmware to have on any color 3200lm just do the 5000K only on 80% max current?

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Lexel wrote:
also why not simply compensate the lumens in the firmware to have on any color 3200lm just do the 5000K only on 80% max current?

Just to get it right: Do you mean a balanced output, i.e. the flashlight will always have let's say 3200 lumens output regardless of the tint's CCT?

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Lux-Perpetua wrote:

Lexel wrote:
also why not simply compensate the lumens in the firmware to have on any color 3200lm just do the 5000K only on 80% max current?

Just to get it right: Do you mean a balanced output, i.e. the flashlight will always have let’s say 3200 lumens output regardless of the tint color?

yes

you could then also make in the firmware an option to blast out Turbo with all LEDs and max current at about 4000K

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Okay, I got you. Smile Good idea. Sofirn did not balance the output on the IF25 (yet). Effectively, not only in perception but also in actual numbers it is brighter on coldwhite than on warmwhite. They also did not implement the fancy feature of using all 4 LEDs on Turbo (yet). However, your ideas definitely belong to the wish list of the UI a perfect flashlight should have.

 

A revised draft concept...

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Ehm...IN!!!!

WTB Titanium 4sevens Quarks & Jetbeam TCR1

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Hmmm… Tint ramp is not a huge thing for me, but then again, I’ve not used a light with tint ramp.

I like the idea of a separate red in the center. Sometimes you need a more gentle and nighttime friendly light. Then again, dropping what I assume is an Osram thrower in the middle defintely adds flexibility. The unicorn flood/throw combination light.

Size — I’m torn on this one. As a pocket light, even the 21700 might be a bit big for my tastes, let alone a 7 LED head. As a holster / shelf light, I like the feel of a 26650 tube, which might be a better size match for a 7 LED head. (reference – I have most recently used an FW3 and EDC18 as my pocket lights, and they are IMHO, on the edge of being to big for pocket EDC)

DIY LT1 battery wrap image. "PDF on Google Drive":https://drive.google.com/open?id=1IHIEOi1NXu868IYNCzIM7D2Ulpxchmww

Fresh Sanyo NCR18650GAs already wrapped "for sale HERE":http://budgetlightforum.com/node/69120 if you like.

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I was wondering about this the other day, and since I saw this, I figured I would ask. Is there any potential advantage to using the red LED in the tint mix? Most phosphor-based white LEDs tend to lack red, right?

ETA: Or is that already the plan?

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I don't know if using the red emitter in combination with the surrounding white emitters would result in a nice beam pattern. I would rather expect it to look weird. So, the red / deep red emitter is more likely to work separately as auxiliary illumination in lowlight scenarios (e.g. camping, preserving one's night vision, no attraction of insects, nightstand light, ...). Using the Osram White Flat 1mm² instead could be interesting to put out more throw as a centered hotspot in combination to the floody LH351D beam.

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This looks like a great concept, I like it. I’d be more of a 4-LED 18650 kind of guy for EDC, but this seems like a good camping trip flashlight that can also serve as a lantern. 5700K while hiking for visibility, mixed tint while cooking food and 2700K when relaxing and reading a book. Just throw on a silicone diffuser and you’ve got yourself a lantern. Maybe a folding hook in the rear to be able to hang it in the tent or from a tree, with a magnet in the cap to keep the hook folded and still being able to stick it to metal surfaces.

I’ve been waiting for my IF25 from Aliexpress since 11/11, but I’m not sure when it will arrive, or how good it will be with the 70CRI 6500K SST-20s. Also waiting for my BLF LT1, but a flashlight like this could replace them both for my use.

Current lights:

Emisar D4V2 SST-20 4000K, D4V2 Ti SST-20 4000K, D4SV2 SST-20 3000K | Fireflies PL47G2 XPL HI V3 3A Lumintop FW1A SST-20 4000K Nitecore LR12 CREE XP-L HD V6 | Sofirn C01S SST-20 4000K | ZebraLight SC53Fc XP-L2 4000K