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.
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:
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.
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?
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.
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.
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 .
There will be cute-3/4 and angie spacers for EE X6, anna spacer for C8. I don't plan to have C8 cute,angie spacers for now, unless there is enough interest, just don't see any advantage when Sofirn C8F triple is available.
Anna-6 has similar TIR size like angie, so throw would be similar with 2 LEDs more, and 50% more lumens.
Would anyone be interested in Samsung LH351C 5000K 70CRI LED at price of 0.7€/pc?
Manufacturer number is SPHWHTL3D50CE4RTQF, flux bin is highest QF bin(310-370lm @700mA,Tj=85C).
This LED is interesting not just because of low price, but because die size is smaller than 4mm2 LEDs like XP-L,LH351D etc. which means narrower beam when used with 3x,4x optics, while lumen output looks fairly impressive, at least up to "stock maximum" of 2A.