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

I was referring to how awesome it would be to run Andruil with your driver…and to be able to customize it to fit my needs perfectly.
Open source makes your hardware more valuable.

@led4power: I plan to mod an Astrolux S41 with Quad XP-E2 red (overcurrent up to 2.5A per LED if they sustain it). Do you think the LD4A driver would work in that flashlight. I’m not sure if the power dissipation might be too high for it. If it works, can you give me some recommendations what I should consider in terms of configurations, please? Thank you!

XP-E2? This test shows maximum at only 2A.

At 10Amps total LD-B4 is better option (in combination with mosled 4xp board) because its much larger heat dissipation capability.

It is fair enough that, having designed them from scratch and trying to make a small business out of his unique designs, l4p decided to not share his driver designs and just sell the drivers as is.

Looking at prices of other BLF drivers, I don't think someone can make and sell them for 10€ anyway. And in that price firmware development is included.

Much simpler FET+7135 costs about that, LD-x4 has much more expensive 4-layer PCB and 2x more components which are all very small, 0402 mostly.

I'm already hearing "what about China?", they even can't make BLF A6 work properly, plus LD-x4 is calibrated via precision external volt. reference, and tested before shipping, so I doubt even China can make it for 10€, definitely not in <1000pcs quantity.

I never said it was wrong. And never asked to open source his work (though that would be awesome). I just pointed out that IMO leveraging open source work of the community would make the LDx drivers better.

It did sound like some sort of request to make his work open source and that made me respond to it :slight_smile:

I agree that open source developments are very much fun for hardcore modders, who want ultimate control of every single aspect of their flashlight. But for the type of modders that want or need a little bit more work taken out of their hands, led4power makes awesome quality components available.

Thank you! You are right, 2.100mA seems to be better than 2.500mA. Is there any better red LED compared to the XP-E2? I could not find anything else so far.

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.