Future development of the maximum luminance of LEDs

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Jerommel
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The_Driver wrote:
Jerommel wrote:
Basically that a less deep reflector is better for throw, when the diameter is fixed. Focal distances are longer with less deep reflector, because it’s a larger parabola than a deep one. Added depth doesn’t add much light hitting the reflector. Your drawing is a bit misleading i.m.h.o. because it ignores the radiation pattern of the LED.

All domeless LEDs have generally the same radation pattern. They are basically lambertion emitters.

I included the radiation diagram (the 2 lobes), and most of the light is emitted at 45° angle, or at least, so i’m told by various members.
It makes sense, because even though the forward bit is brightest, this is just in 1 direction (forward), whereas at 45° it shines around. That’s why the lobes are 100% or factor 1 at 45°
I do have some doubts about this though, since i found an aspheric with the same diameter should catch less light but throws further none the less (Tested SupwildFire reflector compared to B158 lens)
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The depth of a reflector for a given diameter has no noticeable effect on throw. It just changes the proportions of the different parts of the beam. It’s simple math.

You have made these statements multiple times, but your diagrams don’t prove them. They don’t show anything pertaining to luminous intensity (throw) except for the diameter of the reflector.

The focal length of reflectors does not effect throw.

Yeah, i expected we would disagree again on this… Smile
But with every collimating optic the focal length matters regarding the size of the projection.
The question is:
do you want to decrease the focal length in exchange for a few more lumens hitting the reflector?
Look how every bit of increased depth adds less and less degrees of collimated light.
Not only that, but the combined intensity of this rim of light weakens accordingly.
Is it worth it?
I doubt it.
Unless the lobed radiation diagram is incorrect, which could be the case..
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The radiation diagram with the lobes is correct, and so as you make the reflector deeper and deeper the gains in light collection become less. But the interpretation that the light is “weaker” at these angles is not correct. When it comes to throw it’s the luminance (and frontal area) that matters, and the luminance is the same from all angles.

Jerommel
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It’s not weaker, but there’s less of it, otherwise you wouldn’t have those lobes, right?
It’s quite hard to put it into words… Facepalm
But still, experimenting with a B158 lens on a SupWildFire suggest the lobes misrepresent reality..
So i don’t know.
But what strikes me every time this is discussed, is that the focal distances around that “magical” 45° is not taken into account.
In my experience a not so deep reflector makes a better thrower, because it’s a larger parabola size.
But obviously a very very short reflector will simply catch much less light to collimate.
I think the best proportions are between 3:4 and 1:1 (width : depth).

Enderman
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This is kinda going off topic since the thread is about LEDs, but the max intensity of the spot depends on front area.
That means that for a constant diameter, going deeper will increase the front area and therefore lux because the center circle diminishes in size.
A shallower reflector has a large dead center circle.

This has nothing to do with lobes or lumens, all that matters for throw is LED intensity and the front area.
Yes there are diminishing returns as you make a reflector deeper, but it still is an increase in area.
I made this thing years ago for the BLF GT: https://www.desmos.com/calculator/xbaamlzjpc
Move the ‘h’ slider around and you will see how the front area changes.

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Back on topic:
Enderman has found an active area of research into single-crystal phosphors.
These can be used with LEDs and laser diodes as well. Their primary advantage is better thermal conductivity and lower performance degradation when they are hot. “Hot” actually means as low as 60 Celsius. Our high-power LEDs have junction temperature way higher than that and phosphor is hotter still.
Here’s a nice summary of several research papers concentrating on laser use (in German).
There are already manufacturers of such phosphors. For example Crytur.
Disadvantages:

  • cost, according to Endermann the price starts at several hundred USD. How about larger volume?
  • tint high above black body line. Image from Crytur

The_Driver
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I wonder how the phosphor crystals compare to the sintered phosphor that Osram uses.

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The crystals have basically no drop in output till 300C
This means you can have a pretty intense laser directed at it without damage.
One university tested up to 14W of blue laser and got 4000lm but it was spread over a large 5mm crystal IIRC, not all in a concentrated spot.
The crystal was not heatsinked to anything either.

These are my main resources:
https://www.osapublishing.org/oe/abstract.cfm?uri=oe-24-2-a215
http://jss.ecsdl.org/content/5/10/R172.full
https://www.swissphotonics.net/libraries.files/Rossetti.pdf

The_Driver
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That doesn’t fully answer my question though ;).

Enderman
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Sorry that reply was for Agro.
I have no idea what type of phosphor osram uses or how it compares.
Probably a trade secret if I were to guess.

The_Driver
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Enderman wrote:
Sorry that reply was for Agro. I have no idea what type of phosphor osram uses or how it compares. Probably a trade secret if I were to guess.

The Osram Stage LEDs use sintered phosphor .

The_Driver
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The Osram Oslon Boost HX seems like the next big thing.

led4power
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 New (1mm2) king:

 

Enderman
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That’s the CSLNM1.TG right?
The newer and better black flat.
Where did you get it from?

I don’t see anyone selling fewer than 1000 except mouser which has none in stock…
https://octopart.com/search?q=KW%20CSLNM1.TG&start=0

djozz
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So what led is that then?

(if Enderman is correct, Ostar Projection Compact, highest bin 1000 lumen @ 3A, Oslon footprint, neutral thermal pad)

Will you be selling these?

led4power
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 It is CSLNM1.TG, I will put them on sale in few hours. Better be fast because next batch could be in 2-3months, this is new LED so production is started just recently.

Vf is insanely low for 1mm2 die LED, 3.18V@3A and 3.40V @5A, 25C.

BLF member luminarium iaculator already tested this LED in real life vs best old XP-G2 S4 - it beats XP-G2 in throw, that's for sure.

 

djozz
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will keep a check on your site! Smile

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Is there a datasheet somewhere or link to test?

nottawhackjob
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led4power wrote:

 It is CSLNM1.TG, I will put them on sale in few hours. Better be fast because next batch could be in 2-3months, this is new LED so production is started just recently.


Vf is insanely low for 1mm2 die LED, 3.18V@3A and 3.40V @5A, 25C.


BLF member luminarium iaculator already tested this LED in real life vs best old XP-G2 S4 – it beats XP-G2 in throw, that’s for sure.

 

I presume he just drove the XPG2 at the same levels for 1:1 throw comparison. I wonder how the XPG2 would fare driving it up incrementally until it hit its limit at about 6 amps? Or to just cut to the chase, compare them when both are driven up.

Btw while on that topic do ya know about what’s the amp limit on this LED?

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Enderman
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led4power wrote:

 It is CSLNM1.TG, I will put them on sale in few hours. Better be fast because next batch could be in 2-3months, this is new LED so production is started just recently.


Vf is insanely low for 1mm2 die LED, 3.18V@3A and 3.40V @5A, 25C.


BLF member luminarium iaculator already tested this LED in real life vs best old XP-G2 S4 – it beats XP-G2 in throw, that’s for sure.


 


It comes on a copper DTP MCPCB correct?
Is it sold out already or am I too early?
djozz
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I assume it is a bare led, and I have not seen it listed yet.

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djozz wrote:
I assume it is a bare led, and I have not seen it listed yet.

Well, in his pic above, led4power shows it on one of his L4P boards, so maybe it will be available already reflowed. I looked at his site and didn’t see it either.

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Enderman
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Yeah it would be great if I can buy them already reflowed nicely Smile

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Enderman wrote:
Yeah it would be great if I can buy them already reflowed nicely Smile

+1
djozz
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The led is listed at l4p’s site, on 16mm and 20mm board. I hope that bare leds will be sold too?

led4power
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https://led4power.com/product-category/leds1/osram/

Bare,16mm,20mm for now, some triples/quad PCBs later.

Agro
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And quads? Would be interesting in Emisar D4. Wink
EDIT: I see they are planned already. Smile

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led4power wrote:

https://led4power.com/product-category/leds1/osram/


Bare,16mm,20mm for now, some triples/quad PCBs later.


Shoot, I ordered too soon before the bare led was listed. Neven, could you change my order to 6 bare leds, no boards (should be about the same total price), or should I do a request on your website?
Agro
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What 5A 3V constant current driver options are there for e-switch lights?
14*AMC7135 doesn’t sound appealing. More like appalling really.

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nottawhackjob wrote:
led4power wrote:

 It is CSLNM1.TG, I will put them on sale in few hours. Better be fast because next batch could be in 2-3months, this is new LED so production is started just recently.

Vf is insanely low for 1mm2 die LED, 3.18V@3A and 3.40V @5A, 25C.

BLF member luminarium iaculator already tested this LED in real life vs best old XP-G2 S4 - it beats XP-G2 in throw, that's for sure.

 

I presume he just drove the XPG2 at the same levels for 1:1 throw comparison. I wonder how the XPG2 would fare driving it up incrementally until it hit its limit at about 6 amps? Or to just cut to the chase, compare them when both are driven up. Btw while on that topic do ya know about what's the amp limit on this LED?

Numbers he told me are next (host is 1503 Uniquefire):

XP-G2 S4 (old ones with small die) : 245kcd  @4.7A

CSLMN1:                                           315kcd  @5.3A

 

led4power
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djozz wrote:
led4power wrote:

https://led4power.com/product-category/leds1/osram/

Bare,16mm,20mm for now, some triples/quad PCBs later.

Shoot, I ordered too soon before the bare led was listed. Neven, could you change my order to 6 bare leds, no boards (should be about the same total price), or should I do a request on your website?

Ok, I will ship you 6 bare LEDs instead.

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