Can I Direct Drive a u-bin K2?

chadwide

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Can I Direct Drive a u-bin K2?, I'm not to worries about run time, but I want bright, and long LED life. I'm planning on DD from a RCR123. Thanks for any input!
 

ktronik

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Given the high Vf of first run K2's & the Vf shift amount of high Vf LED's, it would be unwise to DD in the long term...but would work to start, depending on the Vf you have...given the high Vf's coming out...

Better to use some sort of current regulation... :)

Ktronik
 

AW

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chadwide said:
So what happens if the voltage out is greater than the voltage in?

You 'll see some ' angry blue ' tint shift and there goes your luxeon :laughing:
 

chadwide

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I may have got that backwards, with a Vf in the 4s, the 3.7 volt input would higher, not lower then the out. Is this acceptable? Can I just throw in a resistor to calm things down?
 

ktronik

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Sorry Dude....yep, you got it right...just hook it up for a second with the meter hooked up see what it reads... under 1500ma & your fine...for now...until the VF drops under use then you may have probs...

Final Lithium voltage is 4.25v (i think)

For that usage I would use AMC7135's... $1ea from AW...this is a LDO... great for mods close to Vf...

enjoy

Ktronik
 

chadwide

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Deos anyone know where to get a regulator that will diliver 1500ma? Looks the the sandwich shop has them up to 1000ma. Thanks for all the help.
 

ktronik

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Dude, the info is all there....I could not be anymore help if I tried...bar making it for you... :)

the AMC7135 is prufect for the job, as I said...

Put 5 (320ma version) in parallel & you got 1600ma...on a nice D heatsink you will have no problem...

But most, 1 cr123A cells won't cut it for current...use two in parallel or a 3.7v 18650 li-lion cell...

Enjoy

Ktronik
 
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