Led4power.com : LD-4 CC linear drivers, ILC-0/1 illuminated tailcaps, optics, MOSX, copper DTP MCPCBs...

After quite some years already since it came out, I have not found a better red led than the XP-E2.

The red Nichia 219B has similar performance both in current and output (I never posted my test results for it), and there is a red chinese XM-size led recently on aliexpress (also tested it without posting the results), that one can handle more current (over 3A) and has a bit more output than the red XP-E2 but at the cost of a considerably bigger die (so worse performance in an optic). And there is no triple board with the XM footprint as far as I know.

Thank you djozz! Would you mind sharing your results with me/us about the red Chinese XM-size LED? Do you have a specific link to the LED on Aliexpress? Maybe I could put this one into a single emitter light.

Will do. I wanted to make a nice post with graphs at some point but never got round to it. I may get you the bare numbers for the time being…

That sounds great to me djozz! I would greatly appreciate it, if you were to send me the raw data you got. Thanks a lot in advance! I would like to try out this Chinese XM-L footprint size LED in some hosts (e.g. 12x in a Skyray King or a single Convoy M1 emitter).

Anyway, I don’t want to hijack Led4Power’s thread any longer for those red LEDs. Sorry for getting a bit offtopic here. :innocent:

One more hijack post: here’s the link, btw the pink ones are lots of fun, they are blue leds partly phosfor converted to red and I get almost 1000 lumen out of them :party: (also never posted the test)

@FlashTom, I posted the Epileds 5050 red led results here: Epileds 5050 (XM-footprint) high power red led, short post with test results.

I just found it. Thank you so much! :+1:

@ led4power:

I’m afraid the LD4B would not technically fit into the Astrolux S41. Do you think 4 XP-E2 would work fine with the LD4A in terms of power dissipation? There is no alternative MCPCB for the S41, so I have to stick with the integrated board. I plan to use the LD4A with 9 amps, i.e. 2.25amps per XP-E2. As the sweet spot seems to be around 2.4amps there should not be any problem to drive the LED to 2.25amps. Or I could use the 6amps setting which means 1.5amps per XP-E2.

What do you think?

I don't see where did you find sweet spot of red XP-E2 to be 2.4A? That's past the point of max. lumen,and way over point of sweet spot. Red and yellow LEDs hate heat, lumen drop is much more significant compared to white LEDs at elevated temps.

I think 1.5A per LED is fine, but since Vf is only ~2.5V, worst power dissipation in driver would be ~(4-2.5)*4.5=6.75Watts, LD-A4 can handle that heat if thermal contact is very good, you need to make something similar to this in your light:

https://led4power.com/product/ld-a4-thermal-enhancement-kit-convoy-s2/

You are right. I must have mistaken those 2.4A with the maximum output of the Nichia 219C and I was probably totally wrong about the sweet spot. Sorry for that and thank you for your suggestions that I will follow. :slight_smile:

Hi Led4Power,
The spacer you have recommended would only fit for single LEDs but not for Triple or Quad optics as the wires need to go through the centre hole of the MCPCB. The spacer however has holes at the outer rim, so it won’t work this way. Would it be sufficient if the MOSFET of the LD4A is the only part that has contact to the flashlight’s head?

Yes, only mosfet generates heat.

Thank you Neven! I’ll check if the spacer can be modified for the right wiring alignment in the S41. Otherwise these so called silicone rubber cubes might be helpful for thermal conductivity from the mosfet to the flashlight’s head.

LH351D 4000K 90CRI in stock(no pics currently):

https://led4power.com/product-category/leds/white/

Within 2weeks 3xp and 4xp copper DTP boards will be in stock,together with mosX2 cute-3,cute-4,angie-4,anna-6XP, so I'll add those later.

Nice additions!

Will there be a DTP board for the Anna-7XP at some point?, or did you mean to say that you already have the board (and the optic?)

There will be ANNA-6XP (and XV of course), but in mosX2 version, as good as DTP.

I bought 7x optics before I made design, later I found 7x is too problematic because spacers for Convoy C8 would be too complicated, so board will be 6x, 7x optics still fits anyway.

did you make any with 4040 footprint?

Are you going to sell the 5.000K CRI70 or CRI90, too?

Of course, cute-3, cute-4, angie-4 will be 31.4mm in diameter and come in 4040 or 3535 footprint; same for anna-6x optics (34mm in diameter).

70CRI Luxeon V has better performance, so I don't think I will stock 70CRI Samsung versions soon. Buying full reels of each variant is too big investment for me right now, so currently I will stock only most interesting LEDs .