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Cabling up power injection

Discussion in 'Computers, Cabling & Other Miscellaneous Hardware' started by Charles Belcher, Aug 11, 2015.

  1. Charles Belcher

    Charles Belcher New Elf

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    Topic: Power injection to a Mega Tree with 9' diameter base using 5m, 30 count, 5V, 2812B rgb strips. All strip inputs are at the bottom of the tree.
    I am having Ray pre-solder pigtails onto both the input and output side of the strip. Male on the input side and female on the output side.
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    I am putting together my order for Ray Wu today and have a question about cabling. Power supplies and controller will go at the center pole just above ground level.
    ___________________


    I understand the wiring guide on page 51 of the 101 Manual. What I don't understand is how to accomplish the diagrams with the black 13.5mm 2 core and 3 core cable and "T's" that Ray sells.


    For example, if I am powering all of the rgb strips from external power supplies and not powering any of the strips from the controller, because the 2812b's are 3 wire, I would only need the one data line coming from the controller to the strips and the voltage + & - would come from the external power supplies--right?

    Let's say for simplistic sake, that I am only connecting one strip per controller channel. Which pigtails, cables and T's would I use and where?


    Next example would be; I jump two adjacent strips together at the top of the tree. So power and data go into the bottom and they are simply plugged together at the top of the tree. Which pigtails, cables and T's would I use in this situation and where?


    Any help would be greatly appreciated.


    Charles
     
  2. Gilrock

    Gilrock Full Time Elf

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    You want all the grounds to connect together. At the power injection point you don't want the power to bridge over from the end of the previous string. I use 3 core cable everywhere and I found the easiest way was to buy the standard 3 core T splitter cables that Ray sells and then I pull the power pin out of the side where it will attach to the previous string. The beauty of it is all my strings can be used interchangeable anywhere. The T cable bridges the data and ground wires but not power since I pulled the pin. Just reach in there with a pair of needle nose and give a twist and pull it out. You need to figure out the right pin based on the wiring standard you developed for yourself. Where the cable T's back to the power supply you only need to connect power and ground.
     
  3. OP
    OP
    Charles Belcher

    Charles Belcher New Elf

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    Gil,


    Good, because the 3 core black 13.5mm is the cable I wanted to use also.

    So if I have two or three power supplies for the mega tree, I can just take raw unconnected 12 gauge wire and jump it between the negative terminals on the power supplies? I thought I read on one of the forums that tying the negatives together was better done at the insertion point(s). Does it matter?


    I see where Ray Wu makes a "T" and the center connector only has two pins, but I guess you would have to use a 2 core cable with 2 pin connector to mate up with that---thus making your system a two cable system, unlike yours where the same cable can go anywhere.


    Charles
     
  4. Gilrock

    Gilrock Full Time Elf

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  5. Habbosrus

    Habbosrus New house (again) 2017

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    I have a 2d, 12 strip mega tree and a 40 row x 75 pixel matrix (up from 20 row x 75 pixel last year). My tree uses the same principle as Gil, 3 core wire & T splitters. My matrix uses the the newer T type splitters for power injection, 3 pin x 3 pin x 2 pin at the T. Both worked well last year with zero problems. My tree is zig zagged and power is injected at the bottom. It uses 12v led strip 3LED/1IC WS2811. The matrix uses 5v WS2812b 30LED/metre. It too is zig zagged and I power inject at one end only (every 5 metres).
    I'm a little confused by your comment regarding jumping 2 adjacent strips together at the top of the tree. You can connect the v+ & v-, but you can't connect the data at the top if you are feeding data from the controller at the bottom of each strip. You can use different methods to bypass the data, such as Gil's suggestion of pulling the pin.
     
  6. fasteddy

    fasteddy I have C.L.A.P Global Moderator Generous Elf

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    I use 2 strips per output that are connected together at the top of the tree with the +v disconnected between the two strips. I then just inject power at the end/bottom of the second strip. this works well using 12vdc, but not sure how good it will work with 5vdc
     
  7. OP
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    Charles Belcher

    Charles Belcher New Elf

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    Habbosrus,


    Thank you for your comments. Just working through all the possibilities.


    Charles
     
  8. i13

    i13 Senior Elf

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    It doesn't matter if you join the negatives together at the supplies or through the strips themselves but they must be somehow joined along every run of pixels on a controller output (you don't need them joined between multiple runs). You need to have the controller's negative output connected as well. It is possible to get a controller that supports more than 150 pixels (one 5 metre strip) per output which is why Fasteddy uses one output for two strips. He mounts the second strip upside-down so the data can leave the first strip at the top and enter the second strip there. It's still ok to power the second strip at the base if you do this as long as their negatives are connected together.

    I know I posted this on your other thread but you haven't yet replied there and this would be a major mistake. If your controller's channels and outputs are the same thing then you're buying the wrong type of controller.
     
  9. OP
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    Charles Belcher

    Charles Belcher New Elf

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    i13,


    Fortunately, I haven't purchased anything yet. I am going through this exercise before I do, in order to make sure that my proposed components will all work together. I know I am asking a lot of questions.


    Charles
     

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