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Thread: Grounding out, let's try and avoid it.

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    Default Grounding out, let's try and avoid it.

    Okay, for the first time yesterday I grounded out an Amber LED through the base. I'm not quite sure what combo of what was going on at that particular moment triggered it, but let's talk about ways of stopping it.

    These Red/Amber colors are odd with their construction. I heard you can light it by putting a neg wire to the base...

    What are peoples experience with this and stopping it? Thermal paste? Thermal epoxy? Thermal tape? Do any of those stop the grounding out?

    I don't have tons of LEDs for this to be a major issue, but I'd love to prevent it anyway.
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    A piece of thermal tape will stop it completely.

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    Sith Acolyte DACOTA's Avatar
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    Do you mean like one wire to the - on the led and then the other touches the led mount/heatsink which the led is touching and you get the led slightly lit?
    "aaah... general kenobi.... you are a bold one."-general grievous

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    Quote Originally Posted by DACOTA
    Do you mean like one wire to the - on the led and then the other touches the led mount/heatsink which the led is touching and you get the led slightly lit?
    I was reading that on a flashlight forum. Pretty scary to me...

    I'll have to find some thermal tape to try. I have paste and epoxy but not the tape... go figure.
    RED LEADER Standing by!

  5. #5

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    Yes on the red/ambers/oranges the base of the stars are electrically connected to the cathode of the led.

    This means that you could connect the positive wire up to the led as normal and the negative up to the bottom of the star (or heatsink, or sabre body if metal and not isolated) and it would light up as normal.

    This can be a problem as unless you are carefull with your wiring its possible to short out the batteries/driver as the sabre casing can be negative.

    I dont know why they did this with the reds as the others arent and its not good design practice.

    I usually use thermal tape as its a sold peice unlike thermal adhesive which unless your very carefull can still leave a bit of the star touching the heatsink.

    Also double check with a DMM before powering anything up is a good habit to get into.
    Phil Higgins


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    I absolutely have to chime in here to confirm X to the Z's problem.

    YES. The Red-O, Red, and Amber constructions (of at LEAST the Lux IIIs)... are awfully strange. And like NeoP said... pretty lousy standard practice.

    Corbin--when designing the BOP I sabers--had ALL sorts of issues wiring up the Darth Necrolosis Staff... which was running 7.2v between both of the LEDs (half for one, half for the other). The problem was that at least one kept shorting through the body, and then fed the FULL 7.2v into one of the Lux IIIs.

    That is not pretty.

    Poor Corbin was having nightmares with the bloody thing, burning LED after LED... and naturally I was of no use (especially a year or so ago), as I had nothing to do with wiring/soldering electronics of any kind at the time.

    Corbin called up/contacted some Lumileds contacts and asked what's the buzz. They told him exactly what you are all here confirming... the strange "we'll negative/ground THESE LEDs out via the heatsink!"

    I don't get it. It's like... And... and... WHHHHHHYYYYYYYYYYYY??!?!?!!!! WHY have tons of people frying $6 LEDs left, right, and up your blade tube?

    Anyhow. Bizarre... but myth = busted.

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    Quote Originally Posted by neophyl
    This means that you could connect the positive wire up to the led as normal and the negative up to the bottom of the star (or heatsink, or sabre body if metal and not isolated) and it would light up as normal.
    Wrong.It does not light up as normal its just barely flickered on,and it only does this if you connect the neg wire to the led and the pos wire to the led base.I tried before my first post both ways.Only the right way I said worked and it was with moderate power.
    "aaah... general kenobi.... you are a bold one."-general grievous

    http://starwars.wikia.com/wiki/Qymaen_jai_sheelal

    Proud owner of the first two Darth Maul conversion kits! Thanks Tim!

  8. #8

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    Dacota thats because the star itself is anodised. That provides a fair amount of resistence normally due to the chemical nature. You scratch it though and you are through the oxide layer to bare metal.

    As the anodised layer is clear its very hard to tell visually so its always better NOT to rely on it.
    Phil Higgins


  9. #9

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    ive been usin artic silver cpu paste, on all mine, and so far i havent had a single led blow out.

    i was really careful when mountin to heatsink not to scratvh the stars undersides, maybe that helped, IDK. but so far im lucky.

    now with this revelation, how will this affect a red lux 3 in the maul sabers?

    i want to do a convert, later this year after the cons im goin to.



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    The only way *I* was able to solve a Luxeon III Red-O short out thing (btw, the Li-Ion batteries SAVED the LEDs)... was to pad up the switch, which was the only thing connecting the separate circuits.

    Padding the switch body prevented its metal from touching the HILT'S metal... and thus, prevented two circuits from "co-mingling".

    I know, I know... that is for TWO separate circuits, and if you're not doing that--it won't be the same.

    However--it's good advice for the Maul setup, which is basically.... TWWWOOOO circuits! heheh :P
    ~~ GREYTALE NOVASTAR (Writer, Director, Choreographer, Sound Designer, Actor, Saber Designer, Vocal Artist)
    ~~ Balance of Power, EP I: "Into The Lion's Den"
    ~~ Balance of Power, EP II: "Ashes of The Phoenix"
    ~~ The Crystal Focus Sound CD Compendiums... are HERE! ~~
    ~~ Nova & Caine's Staged Combat System... comin' SOON!
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