SL Luxeon Jr. Star swap?

VWTim

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Has anyone done this? This is on an older model Jr. Lux with the shorter runtime. I'm not sure how the circuit works as to that Vf bin I need to stay with. IIRC it has a J or K bin Lux 1 like a PWAJ? Would a S**H be overdriven too much when ran on Lithiums?
Thanks in advance,

*edit PYAJ is the installed bin*
 
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Illum

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VWTim said:
Has anyone done this? This is on an older model Jr. Lux with the shorter runtime. I'm not sure how the circuit works as to that Vf bin I need to stay with. IIRC it has a J or K bin Lux 1 like a PWAJ? Would a S**H be overdriven too much when ran on Lithiums?
Thanks in advance,

*edit PYAJ is the installed bin*


I've never modded lights bf, but from personal experience the old Jr Luxeon tends to overeat just on the stock emitter, would'nt replacing the emitter with a higher grade make it overheat faster?

Me <-- N00b when it comes to modding / binning:candle:
 

VWTim

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Well a higher output bin will just increase output for the same efficiency, but going to lover Vf bin will increase heat due to an increased drive. But I'm just not sure how much increase in drive it'll take. If I could find an affordable SXOJ I'd call it a day, but the S**H's seem very prevalent now.
 

rantanplan

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Long time ago I replaced the stock QX1J star in my old SL Lux Jr. with a RX0H and played a little bit with the pot on the driver board. I hadn´t measured the current with the stock luxeon before, but with the RX0H it was something like 380-390 mA (IIRC). I don´t know it exactly but I have vague in mind that the currents were not affected so much by the star swap. They went up a bit, but not too much ... the driver isn´t a very efficient one.

The heatsinking isn´t well made, because only the outer parts of the star are making contact with the body. And another drawback ... the luxeon star is cutted/grinded down to a smaller diameter. A regular star doesn´t fit, until you modify it too. If you do this, check the star for short circuits afterwards, apart from that it´s not a difficult mod.

A swap with a S**H-Bin shouldn´t be a problem. Maybe it decreases lifetime a little bit due to the increased current, but who cares ... the S**H won´t "instaflash", that´s sure and the most important part ;) ...
 

rscanady

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Tim,
I did this with mine quite a while back. It was a pain having to regrind a new star to fit, as previously stated. A T rank with equivalent Vf went in. It is defitnitely underdriven but still brighter.

I did it just to see if I could mostly. WIth the S bin Lux I out these days, that seems like a good swap to me. Maybe an SWOH, hmm I might have to try this. I would definitely measure the current from the board before permanently installing something though. I might play with it this week. I bought a new variable bench power supply so that I can determine the exact Vf of my LED's now. I like it.

Ryan
 

VWTim

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Sounds fun, I just got an SXOH from our buddy GreenLED last week, but I want to save that for my L0P, might have to get another tho.
 

IsaacHayes

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I'm not sure if it's a voltage boost circuit or not. Probably, so current would go up. The new ones with longer runtime have the star thermaly epoxied to the metal ground/heatsink disc. So the older ones are easier to mod. You would want to put some thermal grease or thermal epoxy though to help out with thermal transfer though.
 

Lightingguy321

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The circuit is indeed a boost/regulation module circuit in the jr. lux, it boosts the supplied voltage (2.9 to 3.5 ish) to a 5 volt drive and constant current at something like ~350ma and keeps the supply to the luxeon as steady as possible
 

Lightingguy321

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My junior luxeon has a QYAH binned Luxeon I. It is a fairly good tinted LED, but maybe a little towards the bluish side. I have not really had a chance yet to test what the voltage supplied to the Luxeon is after the forward voltage goes through the regulator.
 
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