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Thread: Power supply needs

  1. #11
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    Default Re: Power supply needs

    Here are some pictures that show power injection. In this case, the prop is my eve pixel strip. I power inject every 25 pixels, first pixel and last pixel (no power from controller).

    In the picture of the strip on the wall you can see my injection wires hanging in front of the wall.

    inject-1,2,3 show how simple power injection is. No Ts no nonsense.

    In next post:

    The picture of the singing tree has a white box behind the tree. This box holds my buck converters and provides power to the strip. One buck drives 25 pixels, 12 to each side of the injection point.

    I also included a picture of the best product in the world and the counter balance that holds my singing trees in place in 70MPH winds.
    Attached Images Attached Images


    2018 - Moving and going to visit my Daughter in New Zealand. Most likely I will be dark or nearly dark, Some static stuff that is simple to put up.

  2. #12
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    Default Re: Power supply needs

    And the rest of the pictures.
    Attached Images Attached Images


    2018 - Moving and going to visit my Daughter in New Zealand. Most likely I will be dark or nearly dark, Some static stuff that is simple to put up.

  3. #13
    Join Date
    Nov 2016
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    Default Re: Power supply needs

    Quote Originally Posted by MartinMueller2003 View Post
    not needed
    Forgive the nit picking, but could you explain why that isn't needed in this case? I'm trying to understand the actual concepts and theory behind all this for my own knowledge, safety, and design going forward. Every single thing I've ever read about power injection mentions tying the V- together from different power sources. Also, something that comes to mind, the opposite is also mentioned, which is NEVER tie the v+'s together from different power supplies. If I used the scenario above with power supplies on opposite ends working inwards to cover about half the pixels, but not overlapping, would this mean the point at which the 2 psu's come together would have to have the power wire for the pixels "break" ? So the point before the next power supply takes over, would basically terminate the power connection? It may seem obvious, but the way I'm picturing it, without that, if you have the power wire connected all the way through, even if the power injection doesn't overlap, they are effectively still connected together if both connected to the same wire right?

  4. #14
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    Default Re: Power supply needs

    You never need to connect the negative between two power supplies "using a dedicated piece of wire". It does not hurt, but it does not help either.

    • V+ and V- from the PSU are a pair that travel together and reference each other.
    • Data and V- are a pair that travel together and reference each other. The reference must be as close to the source and destination of the data as possible.


    The need for V- tied together is driven by the Data wire. The V- needs to be tied together at the point where the data leaves one device (controller or pixel) and enters another device (pixel). If you tried to inject power between two devices (pixels) and did not run a V- between them then the Data line reference would be floating. A floating data reference causes interesting lighting effects (flickering) but not controlled lighting effects.

    In summary: The only place where you MUST tie three wires together is V- at the point where you are injecting power. The three wires are:
    • V- from the previous device (pixel or controller)
    • V- from the destination device (pixel)
    • V- from the PSU injection wire
    Last edited by MartinMueller2003; 10-09-2018 at 06:38 AM.


    2018 - Moving and going to visit my Daughter in New Zealand. Most likely I will be dark or nearly dark, Some static stuff that is simple to put up.

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