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  1. #1
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    QTC Pills (variable resistor) for controlling lights

    Just saw this while looking for a cheap driver for 2 XML's, and thought I'd post it in case somebody has a project that could use it. Looks really cool, though unfortunately for me the only place that seems to sell them is in the UK (great if you are there though). This material is basically a variable resistor (like a potentiometer) where it can be squished and the resistance changes. The link has a video of a min-mag that the author converted to a triple xpg with the QTC as a variable resistor which gets mashed when adjusts the focusing of the light.

    http://budgetlightforum.com/node/1373

    Probably the coolest thing about them is the name - Quantum Tunneling Composite - get em here:

    http://www.mindsetsonline.co.uk/prod...oducts_id=1144

  2. #2
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    Interesting stuff Huffy but I wouldn't go taking my modded flashlight in my carry on baggage, imagine trying to explain to airport security that the squishy material with two wires going into is just like a dimmer switch

  3. #3
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    I would not recommend taking any DIY light in carry on (in the US at least). Might end up on the news, like this poor lady:

    http://www.dailymail.co.uk/news/arti...wards-tag.html

    Seems like some attendants have the idea they are prison guards, give somebody a little power...

    Now how about attaching a QTC pill to the tire and then connect that to a tail light - no complicated electronics, instant (speed controlled) blinky Or it could be built into a mouthguard, just chomp down when you need some extra light, the possibilities are endless!

  4. #4
    Light freak
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    I am getting ready to fly for work and was actually wanting to bring one of my Amoeba lights with me. Now I am thinking not!


    ***

  5. #5
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    Scar, just put it into the "checked luggage", or are you one of those guys that squeezes all of their belongings into three oversized carry on bags?

    Huffy, I ride in a group at night more times than not and I've often thought about how to make a brake light work, your suggestion immediately had me thinking of a small piece on the brake lever. The harder you apply the brakes, the brighter your rear brake light, the less llikely your mates are going to run up your arse, or off the track to avoid you

  6. #6
    Light freak
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    Nope, not one of those guys. They are the ones that I always end up sitting next to! Up and down the whole flight getting random stuff out of all 3 carry ons, then scrambling to get it all stuffed back in before the flight lands.

    Would just be a real bummer to open up your luggage and find your light missing


    ***

  7. #7
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    Very interesting stuff, Can we have some more technical data on it? I wonder how efficient could it be, because if it works like a variable resistor or a pot it wouldn't be on the high end...

  8. #8
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    Quote Originally Posted by scar View Post
    Would just be a real bummer to open up your luggage and find your light missing ***
    It happens. I "lost" a nice 18650 XPG flashlight and a nice folding knife from checked baggage last year. Funny thing was, the bag was still zipped up. After discovering the loss, I called the airline to complain. Their response was along the lines of "well sometimes bags come open in handling and things fall out. The handlers close them up so more things don't fall out". Odd that the dirty socks or underwear didn't fall out, only the valuable things.

  9. #9
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    I'm dying to try a QTC pill with a Quazzle L333 (single mode)... can anyone pipe up and correct my "understanding" (and I use that term very loosely -- maybe I should call it a notion) that the QTC changes amperage, not voltage? Any other ideas for/against? (I haven't actually received the pills yet, so maybe once I get stuff in the post, all my questions will be answered.)

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