Chapter 2: XM-L2 U2 3C emitters, heat dissipation improvements, and increasing driver output.
Got a pair on 16mm and pair on 20mm noctigon mcpcbs. 20mm was too big (so emitters transferred to stock plate so i could see the differences in tint etc) to fit case as case measured exactly 20mm diameter but mcpcbs are actually slightly larger and no room on noctigons to file down enough.
The point was because I wanted to test a theory;
“Faster heat can be transferred from emitters to outer case, the lower the overall temps due to lower emitter temps” combined with this test I found HERE: Emitter Test Results Copper vs Aluminum . Shows higher output (and FLIR images courtesy of Ledoman) yet much lower emitter temps.
More on that later. Light is v 1.2 with XM-L2 U2 3C emitters. Next up was better heat dissipation by the case itself. So in comes Vancbiker (MTBR) with a cnc’d solution for these and Yindings:
And In first post shows standing temp on high (with air flow generator) of 150deg F. Next pic is v. 1.2 thermal test with the gopro/heatsink adapter:
21 deg decrease in internal temp!!! ~14% temp improvement Simply with that mount and thermal paste between it and case.
Next: Increasing Driver output. Another thnx to Ledoman for the “how to” for sense resistor mod.
Test of now pushing 2.77A (from 2.27A stock) to the emitters. Did try 3.29 on v 1.2 but thermal shut down was longer than stock but took around 4 mins with airflow generator. Case temps hit 170F. Mod was stack r500 resistor on top in parallel, 1= 2.77A, 2 = 3.29A.
2.77A output on high
8F increase in case temp but still below 140F at the hottest point (besides directly next to emitters) in case. NICE. Light out put on high was really sweet for something so small.
- Side note: ALL thermal tests were constant controlled tests. Room temp, duration of test was 15mins with a 30 sec “cycle air off” to simulate brief stop for drink/catch breath during a ride. Vancs adapter did something that didnt happen prior. First tests before that adapter cycle off and back on of fans, case temp only dropped down 1-2 degs and stayed. With Vanc’s adapter case temps rose more slowly, a few degrees less (not max but total # of) and once fans back on, fairly quickly returned to “normal temps”.