TK's Emisar D4 review

[tocirahl]

@Firelight2

I second that request. Can anyone do the calculation for XPL HI so we can see how it compares to to XPG2 and 219C in this light?

Source (scaled up to the V3 bin)

XP-L Hi, and would-be-XP-L featuring in recent SRK-clones, two emitter tests

First the XP-L Hi, I'm a bit late to that party. I tested a U5 bin 5000K led from Mouser. there's better bins around since then, so the performance can be a bit better than in this test. Pflexpro did already some convincing testing of the XP-L Hi inside flashlights. [image] [image] (stereo picure) It is build a bit different than what we are used to from Cree, and in fact the same buid-up as what I saw with the Nichia 219C. It looks like they build the complete blue led, then added a phosfor …

• the 219C version puts out 3800 OTF lumens = 950 OTF lumens / LED = 1190 LED lumens / LED

• the XP-G2 version puts out 3300 OTF lumens = 825 OTF lumens / LED = 1030 LED lumens / LED

• the XP-L HI version puts out 4300 OTF lumens = 1075 OTF lumens / LED = 1345 LED lumens / LED

Running that through the spreadsheet, we get:

• 219C runs at roughly 4.92 A, 3.425 V = 16.85W ==> 56.4 OTF lumens / W

• XP-G2 runs at roughly 3.11A, 3.755V = 11.67W ==> 70.7 OTF lumens / W

• XP-L HI runs at roughly 3.10A, 3.42V = 10.60W ==> 101.4 OTF lumens / W

… and extrapolating a little from that, we can calculate the approximate amount of heat:

• 219c: 16.85 W * ((300 - 56.4 lm/W) / 300) * 4 = 54.7 W of heat (and 12.67 W of light)

• XP-G2: 11.67 W * ((300 - 70.7 lm/W) / 300) * 4 = 35.7 W of heat (and 11.00 W of light)

• XP-L HI: 10.60W * ((300 - 101.4 lm/W) / 300) * 4 = 28.1 W of heat (and 14.33 W of light)

… this seems a bit too optimistic? Did I do my math incorrectly?