Need help finding a "breaker" no bigger than 1/4 in??

Discussion in 'The Projects Forum' started by zach.s., Oct 28, 2013.

  1. zach.s.

    Thread Starter New Member

    Oct 25, 2013
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    Hey all, I am not sure this is the right place, but I figure it is worth a shot. I am working on a project with LEDs attaching to a 1/8in thick plastic rod. The circuit is on the micro scale (1mm LEDs, 0.016 in copper wire, L41 watch batteries, etc.), but I am having a trouble with the wires touching and short circuiting, making the LEDs flicker.

    Is there some sort of "micro/mini" breaker or pass that can flip off during a short? Or some sort of method or circuit design that can help? It cant be bigger than 1/4 of an inch. I don't even know where to begin looking!

    P.S. the circuit is a simple parallel circuit with 5 LEDs and a couple watch batteries.

    Thanks!

    -Zach
     
  2. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    A surface-mount resettable fuse comes to mind, but the current needed to trip it would probably flatten the battery in next to no time :(.
    If the wires are enamelled they can touch without shorting.
    What total LED current are you drawing?
     
  3. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    1/4" in which dimensions? Length? Width? Height?

    Alec has the "proper" answer though.. Insulation on the wires
     
  4. wmodavis

    Well-Known Member

    Oct 23, 2010
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    That is overly complicated approach. Use insulated wire so they will not short.
     
  5. MaxHeadRoom

    Expert

    Jul 18, 2013
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    26AWG magnet wire.
    Max.
     
  6. #12

    Expert

    Nov 30, 2010
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    Krylon Clear spray paint.
     
  7. JohnInTX

    Moderator

    Jun 26, 2012
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  8. zach.s.

    Thread Starter New Member

    Oct 25, 2013
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    Thanks for all the feedback! Here is a curve ball for your consideration:

    The wires have to be bare so that the LED can make electrical contact at any point along the rods 7 inch length. Think of sliding a "bead" onto the rod that is the LED and it will light up at any point, however, if any metal connects the two bare wires, it obviously shorts.

    I am working on the current draw and heat consequences of the short now.
     
  9. JohnInTX

    Moderator

    Jun 26, 2012
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    Maybe you can get the wires more mechanically stable. Some thoughts:

    Cross drill the rod at each end and thread the wire through the holes pulling it tight so that it won't flop around.

    Stretch the wire taut on your bench and paint one side with epoxy (J-B Quick would be excellent) Place the rod on the painted epoxied wire. Wait until the epoxy cures. Repeat for the other wire.

    Mechanically secure insulated that enameled magnet wire to the rod, pulling it tight. Scrape the enamel to bare the conductor.

    Consider music wire. Very stiff and less likely to move around.

    As long as you have the epoxy out, stick down one of the SMT polyfuses for protection.

    Have fun!
     
  10. gerty

    AAC Fanatic!

    Aug 30, 2007
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  11. zach.s.

    Thread Starter New Member

    Oct 25, 2013
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    0
    Ill definitely look into this, it gives me some ideas. However, I am less concerned about the actual wires crossing and more concerned about a foreign object shorting or even a drop of water.
     
  12. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    conformal coat it..
    or hot glue
    or teflon tube slipped over the exposed areas
     
  13. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    Same here. I started using this back when wire wrap ruled the world but I still prefer it when prototyping with SMD parts.

    I obtained a bunch in 10 colors off EBay... but seems the guy's prices have gone to the absurd. Seems I'll have to re-buy full spools off the brick & mortar distributors.
     
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