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Designing an outdoor electronic product (LED tree)

  1. Jul 25, 2012 #1
    Hello,
    I thought I'd run this past you guys.

    My wife wants to start making LED trees for outside use.
    I have been running a part time solar power business, but all my stuff comes assembled to a degree. I have no idea how electrical code might come into play regarding electrical construction from scratch.
    Someone told me that it doesn't matter a long as a certified power supply is used.
    So I am very curious about that, like I said, I have no experience selling home brewed electronics.

    And then the actual design of these.... is there actually a method that is required as far as wiring, or is it just whatever works?
    I'm thinking copper or aluminum tree frame, and then wire all the LED's up, and wrap everything with green or brown fabric, then coat in a UV stable paint or epoxy.
    I was thinking of wiring the LED's, wire, and resistors up, using little pieces of tape to hold them in place until the "wrapping" goes over top.



    12 or 24 v dc outdoor power supply and start cranking them out?


    ANY input would be great!!
     
  2. jcsd
  3. Jul 25, 2012 #2

    DaveC426913

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    Does the aluminum or copper structure of the tree have anything to do with the conductance of power to the lights?

    If so, it sounds like what you've got there is a live 6 foot human bug zapper!
     
  4. Jul 25, 2012 #3
    haha, no, just structural.

    i guess what i want to know, is what materials need to be used on connections, etc, like heat shrink tubing, to make it safe and "legal"

    ?
     
  5. Jul 25, 2012 #4

    Danger

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    I've used a connector system that is definitely safe, although I have no idea as to its legality. If something is to be exposed to the elements, I use a hot glue gun or my make-up kit liquid latex to encase the joint, then apply shrink tubing over it.
     
  6. Jul 25, 2012 #5

    DaveC426913

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    Tried this. Not a good idea. The heat from the electrical connection can melt the glue.

    parkland, is this for personal use or are you selling them?
     
  7. Jul 25, 2012 #6

    My wife wants to make them and sell them as a custom made to order business, I need to help her with the electrical wiring and safety part of it.

    Upon reflection, there really is no way to get certification on a product that get's designed differently every time....
     
  8. Jul 25, 2012 #7

    Danger

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    I don't see how that affects anything. Although I've never noticed melting, the glue or latex is still confined within the shrink capsule and provides the extra moisture seal that it is intended for.
     
  9. Jul 25, 2012 #8
    I've always tried to use silicone for stuff like that ....???
     
  10. Jul 25, 2012 #9

    Bobbywhy

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    The requirements for "low voltage" devices are less strict that for say, 110 volts. Check your local electric codes.
    A metal tree could be the "ground or negative" side of a dc circuit, meaning you could use only one wire to distribute the "positive" side of your LEDs' power. LEDs require a range of voltage/currents to operate, so you need a competent electronics person to help you design the power supply. All electrical connections for use outside must be waterproof. I like silicone, personally.
     
  11. Jul 26, 2012 #10

    Danger

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    That would likely be my first choice, but for 2 reasons. One is cost; glue sticks and latex are a lot cheaper, and I'm on a disability income. The other is that I'm allergic to acetic acid, which silicone releases while curing. It's a minor issue on this scale, but still irritating.
     
  12. Jul 26, 2012 #11

    AlephZero

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    That statement doesn't make any sense to me. There must be some standard codes of practice that you should follow for the design and construction. (I have no idea what they are, because I don't live in your country and I'm not an EE, but it's very hard to believe they don't exist). In any case you will need to carry out some safety test procedures on every item before you ship it, unless you are either a fool or a knave, or you have very good lawyers!

    For example in the EU, any electrical device that is sold commercially must meet the "CE" safety standards, and be marked to show it is compliant with them. AFAIK the CE standard is recognised as equivalent to "national" standards by many other countries including the USA, so companies trading internationally don't have to re-certify their products in every country they want to sell to.

    The fact that "every device is a one-off" isn't a get-out clause. You can to have a "generic" set of design rules and quality standards that cover the whole range of devices. If you need formal test certificates to demonstrate safety compliance, you can test some representative designs built to those standards, including the "worst case" scenarios that might occur.
     
    Last edited: Jul 26, 2012
  13. Jul 26, 2012 #12
    If there were a set of instructions or rules, I'm on the hunt for them.

    This is a very new challenge to me....
     
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