Brighter at low currents: RXOH Lux I or TXOH Lux III??

buymysoul

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Sorry guys, I know this is probably pretty common knowledge, but I couldn't find an answer with the search function.

I'm thinking about getting Miller Mods to upgrade my arc AAA and was wondering which would be brighter (and whiter) at 3/4Watt, a RXOH Luxeon I or a TXOH Luxeon III?

I don't know much about the efficiency of LEDs or if the color rendition changes at different currents and was hoping someone could enlighten me.

Thanks,

Robin
 

MillerMods

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Morelite said:
The RXOH Luxeon I will be around 30 lumens, and closer to its rated tint

The TXOH lux III will be around 15-17 lumens, but tint can vary from its rated range.

I don't have a foggy clue where you get these numbers, but they aren't based on anything I've ever seen or heard.

The reason a T-bin lux 3 is only rated at about 80 lumens is because they are less efficient at higher drive currents, not because they are only a third the brightness when driven at 1 watt as opposed to 3 watts. The curve is not at all linear, and a T-bin lux III and an R-bin Lux I are nearly identical when driven at the same current.
 

HarryN

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If I correctly understand the question, it relates to which will put out more light for a given power.

I am pretty sure that if both the RXOH and TXOH are driven at 350ma, the T bin Lux III will have a lower Vf than the Lux I, making it more efficient, and producing more Lumens / watt.

At the same current (lets continue using 350ma as the example), then I am pretty sure I agree with MillerMods that they will have virtually idential Lumens output. In that case, then the T bin would provide slightly longer run time. Please correct me if I am off here.
 

buymysoul

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Ah, thanks a lot guys, that's exactly what I wanted to know.

(Miller, I'm debating whether I want to use my head or one of yours and whether or not I want the parabloic mod. Once I decide, you'll be hearing from me :) )
 

IsaacHayes

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Yup, the RX0H Vf is tested at 350ma, and the TX0H is tested at 700ma. So when both are tested at the same current, the TX0H will always have the lower Vf, therefore being more efficient and drawing more current in voltage boost applications.
So the TX0H in the MM would be brighter.

And a lux1 R bin is about equal to a lux3 T bin when both are at the same currents.
 

BentHeadTX

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IsaacHayes said:
Yup, the RX0H Vf is tested at 350ma, and the TX0H is tested at 700ma. So when both are tested at the same current, the TX0H will always have the lower Vf, therefore being more efficient and drawing more current in voltage boost applications.
So the TX0H in the MM would be brighter.

And a lux1 R bin is about equal to a lux3 T bin when both are at the same currents.

What Isaac said,

Case in point was the labor put into the Peak Pacific AAA to get the runtime at specification. They stated they went with a LuxeonIII since it would be brighter and give better runtimes. Have no idea of the bin code but my guess is a T--H to give that lower Vf they require. Robyn said they had to pre-test and hand pick the Luxeons to get the performance and efficiency they wanted.

I always go for the lowest Vf possible, used R2H luxeonI's for years and have a WX1S for a LuxeonV. Personally, I would prefer a T--H over a U--L or U--M any day!
 
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