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Pirate King
07-30-2006, 09:18 AM
Wasn't really sure where to put this, since I don't think anyone's actually thought about it. I bought the LED strings from Tim durring the scratch and dent auction, and I was thinking of using them to make some cheap sabers with PVC or something, a couple as gifts, maybe sell the rest to people who want something shiny, but don't have the money for a tough dueling saber. Anyone know what kind of resistance those things needed? They're all green, so they originally were powered by 6 batteries.

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xwingband
07-30-2006, 01:02 PM
I'd go to a resistance calculator and guess a bit. Even though it was 6AA (Luke ROTJ I'm assuming) it ran on 4.5V. You however can run an MR brighter on 6V... so there is some leeway.

I'm guessing they're in the 10mA range... for 64 LED that's 640mA. I think it's a reasonable guess based on running the 3W. I'd start with a normal resistor you'd put for a 3W and when in doubt over-resist it!

<center>Read the FAQ (http://www.thecustomsabershop.com/sabers/forum/topic.asp?TOPIC_ID=552) or x-wing won't be happy. :(
Before posting did you check the Thread Index (http://www.thecustomsabershop.com/sabers/forum/topic.asp?TOPIC_ID=577)?.

http://img508.imageshack.us/img508/6703/xwing8az.gif</center>

erv
12-04-2006, 10:27 PM
mmmm sounds weird you need a resistor to run the string.... If my memory's good, each led has a resistor attached to it on the LED string, so the system can be powered by a voltage without current limitation.
My vader string has those SMD's resistors mounted on the string, the luke might have the same except that the resistor is different. The luke is 6AA powered because the green LEDs might have a higher forward voltage. I did not check on my luke but I think that model has the 6AA in serie, not 3+3 in // like older model. That's done to increase autonomy (if we can say so, current is not regulated at all, brightness just fades out with the batteries depletion).
Just try powering the string with a wall mount adapter that has a selector for the voltage and start as low as you can (probably 3V) and go to 6V max.
Erv'

Novastar
04-27-2007, 11:47 AM
I hate to re-open old wounds (threads), heheh...

but does anyone know the ACTUAL numbers on the driving of an FX board?

That is to say... Ultra states (or once stated) on his website:

MR LEDs are rated at 20ma. There are 64. 64 x 20ma = 1280ma.

If that were true, with that in mind, you COULD use a K2 and find a way to drive the MR to full capacity (as Xwing states).

But... does the board resist too much? Is it actually capable (without modification) of driving the LEDs to their max rated 20ma?

Plus, I'm sure each board varies because of the nature of LEDs/resistors. If anyone has the data per each board... I think it might be a great sticky to post something like:

* MR saber version, year
* Un-modified max driving
* What the LEDs are rated for
* What the approximate "top" voltage is that you can give (probably around 5.2v)

Some of this I already know, but I think it could be a useful sticky. Anyhow. If any of this makes sense... :)