Xp-g- Mtbr.com

1. ## Xp-g

Quick question re the new but not yet available XP-G.

"The cool white XLamp XP-G provides 139 lumens and 132 lumens per Watt at 350 mA. Driven at 1 A, the XP-G produces 345 lumens, which is 37 percent brighter and 53 percent more efficient than the brightest XR-E LED. "

Does this mean we can expect to see forward voltages considerably lower than XR-E and even the XP-E, maybe below 3v @1A?

Anyone prepared to take a guess, or better still, know?

2. I didn't do the math, but it seems likely that such advances are still possible

3. Originally Posted by emu26
Anyone prepared to take a guess, or better still, know?
Edumacated guess:
A lot of the improvements seem to be merely based on the larger die (2 sq mm) so the current density is halved. Hence XPG [email protected] Vf will be similar to XPE 500mA Vf, 500 ~ 250 etc.
From here looks like you can expect aroundabouts 0.2V drop.

Note an easy way to achieve a lower Vf is to mount the LEDs on a thermal insulator.

4. "The cool white XLamp XP-G provides 139 lumens and 132 lumens per Watt at 350 mA. Driven at 1 A, the XP-G produces 345 lumens, which is 37 percent brighter and 53 percent more efficient than the brightest XR-E LED. "
139 lm produced with 350 mA mean that input power is : 139/132=1.053W
Then U = P/I = 1.053 / 0.350 = 3.01 V

MC-E M bin versus XP-G , trying to give the same lumens output, and calculating the electrical power needed : (on XP-G, max current supposed to be 1A, and multi-nose-meter said vf is 3.2V)

<table border="0" cellspacing="0" cols="5" frame="void" rules="none"> <colgroup><col width="80"><col width="83"><col width="89"><col width="103"><col width="105"></colgroup> <tbody> <tr> <td style="border-top: 3px solid rgb(0, 0, 0); border-left: 3px solid rgb(0, 0, 0); border-bottom: 3px solid rgb(0, 0, 0);" align="left" height="19" width="80">Nb MC-E
</td> <td style="border-top: 3px solid rgb(0, 0, 0); border-bottom: 3px solid rgb(0, 0, 0);" sdval="1" sdnum="1036;" align="right" width="83">1</td> <td style="border-top: 3px solid rgb(0, 0, 0); border-bottom: 3px solid rgb(0, 0, 0);" sdval="2" sdnum="1036;" align="right" width="89">2</td> <td style="border-top: 3px solid rgb(0, 0, 0); border-bottom: 3px solid rgb(0, 0, 0);" sdval="3" sdnum="1036;" align="right" width="103">3</td> <td style="border-top: 3px solid rgb(0, 0, 0); border-right: 3px solid rgb(0, 0, 0); border-bottom: 3px solid rgb(0, 0, 0);" sdval="4" sdnum="1036;" align="right" width="105">4</td> </tr> <tr> <td style="border-left: 3px solid rgb(0, 0, 0);" align="left" height="19">Lumens :</td> <td sdval="728" sdnum="1036;" align="right">728</td> <td sdval="1456" sdnum="1036;" align="right">1456</td> <td sdval="2184" sdnum="1036;" align="right">2184</td> <td style="border-right: 3px solid rgb(0, 0, 0);" sdval="2912" sdnum="1036;" align="right">2912</td> </tr> <tr> <td style="border-left: 3px solid rgb(0, 0, 0); border-bottom: 3px solid rgb(0, 0, 0);" align="left" height="19">P input :</td> <td style="border-bottom: 3px solid rgb(0, 0, 0);" sdval="9,52" sdnum="1036;" align="right">9,52</td> <td style="border-bottom: 3px solid rgb(0, 0, 0);" sdval="19,04" sdnum="1036;" align="right">19,04</td> <td style="border-bottom: 3px solid rgb(0, 0, 0);" sdval="28,56" sdnum="1036;" align="right">28,56</td> <td style="border-right: 3px solid rgb(0, 0, 0); border-bottom: 3px solid rgb(0, 0, 0);" sdval="38,08" sdnum="1036;" align="right">38,08</td> </tr> <tr> <td align="left" height="17">
</td> <td align="left">
</td> <td align="left">
</td> <td align="left">
</td> <td align="left">
</td> </tr> <tr> <td style="border-top: 3px solid rgb(0, 0, 0); border-left: 3px solid rgb(0, 0, 0); border-bottom: 3px solid rgb(0, 0, 0);" align="left" height="19">Nb XP-G</td> <td style="border-top: 3px solid rgb(0, 0, 0); border-bottom: 3px solid rgb(0, 0, 0);" sdval="1" sdnum="1036;" align="right">1</td> <td style="border-top: 3px solid rgb(0, 0, 0); border-bottom: 3px solid rgb(0, 0, 0);" sdval="4" sdnum="1036;" align="right">4</td> <td style="border-top: 3px solid rgb(0, 0, 0); border-bottom: 3px solid rgb(0, 0, 0);" sdval="6" sdnum="1036;" align="right">6</td> <td style="border-top: 3px solid rgb(0, 0, 0); border-right: 3px solid rgb(0, 0, 0); border-bottom: 3px solid rgb(0, 0, 0);" sdval="9" sdnum="1036;" align="right">9</td> </tr> <tr> <td style="border-left: 3px solid rgb(0, 0, 0);" align="left" height="19">Lumens :</td> <td sdval="345" sdnum="1036;" align="right">345</td> <td sdval="1380" sdnum="1036;" align="right">1380</td> <td sdval="2070" sdnum="1036;" align="right">2070</td> <td style="border-right: 3px solid rgb(0, 0, 0);" sdval="3105" sdnum="1036;" align="right">3105</td> </tr> <tr> <td style="border-left: 3px solid rgb(0, 0, 0); border-bottom: 3px solid rgb(0, 0, 0);" align="left" height="19">P input :</td> <td style="border-bottom: 3px solid rgb(0, 0, 0);" sdval="3,2" sdnum="1036;" align="right">3,2</td> <td style="border-bottom: 3px solid rgb(0, 0, 0);" sdval="12,8" sdnum="1036;" align="right">12,8</td> <td style="border-bottom: 3px solid rgb(0, 0, 0);" sdval="19,2" sdnum="1036;" align="right">19,2</td> <td style="border-right: 3px solid rgb(0, 0, 0); border-bottom: 3px solid rgb(0, 0, 0);" sdval="28,8" sdnum="1036;" align="right">28,8</td> </tr> </tbody> </table>
<table border="0" cellspacing="0" cols="5" frame="void" rules="none"> <colgroup><col width="80"><col width="83"><col width="89"><col width="103"><col width="105"></colgroup> <tbody> <tr> <td align="left" height="19" width="80">Gain of power :
</td> <td align="left" width="83">
</td> <td sdval="0,327731092436975" sdnum="1036;0;0%" align="right" width="89">33%</td> <td sdval="0,327731092436975" sdnum="1036;0;0%" align="right" width="103">33%</td> <td sdval="0,243697478991597" sdnum="1036;0;0%" align="right" width="105">24%</td> </tr> </tbody> </table>
The questions are form-factor, with lenses that could have a good efficiency, Thermal resistance , and the color rendering index. Too much blue is boring for my eyes.
2 Round stars with 3 real neutral white of them on each , and some good 3 lenses-PMMA (Carclo 20mm Triple Optics for XPE OR Khatod one are they as good as MC-E optics ?) may be a good starting point for me... Same power as 2 MC-E and a LOT of light....
TTGV

5. Cool white and I'm presuming that means Blue ish hopefully works best for me on wet muddy type ground, I'm running a Q5 spot currently to raise the colour temperate of my MC-E M Bin although the light output difference is barely noticeable the colour is much improved.

So hopefully this will replace my Q5, bluer with 30-50% more power in the game

Hopefully they'll role this into the MC-E for a boost in output and bring the colour temperate out of the yellow spectrum aswell, then role on the winter night rides

6. I was able to see an XP-G today at a lighting seminar in Philly. Wow!! super, super tiny and incredibly bright. Blows away even my XP-Es. Full production begins in July, way ahead of schedule. Now I just need a souce that mounts them. Hopefully Cutter will have them quickly ... I cannot imagine a Trout Light with 6 of those in it. Truly amazing.

7. The hunt for a DX full power 1000ma Regulated Torch will commence likely early September then, just in time to replace with 1200ma Q5.

2 of these and move the MC-E to the bars is possible, reduce head weight and improved range and colour

Role on the winter

8. You're unlikely to see large Vf drops in any white LED because the forward voltage drop is related to the bandgap of the semiconductor used to produce the light, which is in turn related to the wavelength of the light produced. So, basically, if it's still going to be white, there's not going to be any Vf reductions.

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