need help connecting a luxeon V

hello everyone, I just recieved my first luxeon V LEDs. I have 4 white and 4 cyan. the thing is that I don't know what is the optimun voltage and mA to which I should connect them without a resistor. Can someone here help me with that? /ubbthreads/images/graemlins/confused.gif

For the white LuxV you want 9 volts from the batteries, so 6AA, 6C, or 6D will work well. 700mA to the LED is the safest.

I'm not sure about the cyan ones, I have never used those.

Whoa there! 9V with no resistor is quite on the edge for one luxV! Depending on the bin code of the leds, the vf should be arround 7.2V IIRC
I recommend a current regulated converter if you plan on using 9V.
Also remember that you need to heatsink it down before running it for long.

All of the space needles are still running strong. /ubbthreads/images/graemlins/tongue.gif

Flashniac, it is best and much safer to at least use a resitor if you can get one.

Sure but SN2s used selected bins for higher vf and use the massive hotlips heatsinks. The original Mr Bulk's SN2s had even larger heatsinks press-fitted into the body... In addition, 3 cr123s limited the current by themselves due to the internal resistance; using li-ion cells, for instance is another story...
I'm not even considering how much faster your emitter will loose brightness with that setup.
It's a good idea to use a current regulated setup IMHO.

KFC is correct about 3x CR123's internal resistance limiting current to lux.

if you try using 2x 18650 in the same setup, it will supernova out in a few short minutes. don't be fooled by lower voltage, li-ion's internal resistance is very low. 2x 18650 can deliver 50+ amps to your luxeon

[ QUOTE ]
Former_Mag_User said:
All of the space needles are still running strong. /ubbthreads/images/graemlins/tongue.gif

Flashniac, it is best and much safer to at least use a resitor if you can get one.

[/ QUOTE ]

Ever compare them to a new same-flux binned LED driven at 1A?

Someone sent me a TNC Hyperlux V to modify for them, and it was a night and day difference in brightness compared to a Lux III driven at 800mA behind a tiny 17mm reflector, and the Luxeon V driven DD off 3x123s behind TNC's huge reflector; The Luxeon III won hands down...

Sure, it still ran, but, it didn't run well - phosphor degradation is real.

As to the question: I'd suggest using 3x123s, coupled with either a resistor in direct drive, or a DB700-DB1000 convertor from Dat2Zip's sandwich shoppe so you avoid damage to the LED. 700mA to the Luxeon V is the recommended current input.

Good luck. /ubbthreads/images/graemlins/smile.gif

Ooops, I meant 6 cell NiMh. /ubbthreads/images/graemlins/ohgeez.gif
That will give around 7.2 volts.

Mea Culpa


Of course a resistor could still be used here for a bit more sanity.

I've had extremely good luck hooking up my Lux V. I used an Aleph3 head, a Vital Gear FB3 body/tailcap that holds 3xRCR123A cells. The light uses a Downboy 750. I wouldn't put more then 750mA through the Lux V. In my set up it runs a very warm 5.25 watts. That is a lot.

It has a very good throw beam that is almost as good as a Lux III and a superior spill light that is better than a single Lux III could do.