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New Mega Tree

Discussion in 'Mega, Mini, Spiral & Pixel Trees' started by sweepa, Sep 11, 2017.

  1. sweepa

    sweepa New Elf

    Dec 13, 2012
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    HI Everyone,

    I plan to build two new mega trees one for our shop and one for our display, im plan to build it using the megatree calculator from lightshowhub.
    It will be 8 metres tall and 3 metres wide at the bottom with a 200 mm gap from the ground to the first pixel the top ring 500 mm it will be a 270 degree tree. The calculator represents well with those specs.
    The calc shows the strings to have 150 pixels at 2 inch spacing as im using the mega tree strips from boscoyo.
    The power consumption is in the range of 2250 watts for all 50 strings.
    Do you think 50 strips will fit on the tree as it stands as i said the calculator seems to fit them on with no problems.
    Power supplies if i use a 350 watt will need around 6-7 of them.
    My biggest concern is the old question should i use 5volts or go with 12 volts i think the only concern would be the amount of power injection, are there any pros or cons for either?

    Any advice would be welcomed.
  2. Doctor_007

    Doctor_007 Apprentice Elf

    Apr 28, 2017
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    Hi @sweepa,

    This is my first year in this hobby, however I do know electrical/electronic theory.

    Broadly speaking if you use a 5V supply you'll require less power, hence less PSU's required, but won't be able to supply very far so most likely need to power inject at bottom and top. If you use a 12V supply you'll increase the power required,
    hence more PSU's, however may only need to power from one end. So running at 12V can be more convenient with less cabling required but will cost a few extra PSU's. It's really a personal preference and I'm using all 12V for my lights.

  3. scamper

    scamper Senior Elf

    Jan 5, 2014
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    Find Me On:
    Yes, what the Doc said about power, I am running 75 pixels per strip and am going to supply power at the bottom only using 5v, Normally I would only usually go 50, but I figure if I get any problems, I will drop the brightness a bit which should alleviate that.
    I have heard a lot of people say they go 150 pixels on 12v before power injecting, so that would be the way I would go.
    As far as top ring goes, I would just work it out, each strip is about 20mm wide, so 50 strings is 1m. if the diameter is 500mm then the circumference would be 1.5m, then 270 degree tree would be 1125mm so as long as my guess at the width of the strips is ok, then it should be fine :confused:
    (It's way too late to be doing math)
  4. marmalade

    marmalade cats & pixels

    Dec 1, 2015
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    my tree is only medium size with 42 on each string,arranged in a zig zag fashion. 5V injected at the bottom of each string (which is essentially then an 84 pixel long string, powered from both ends)

    All pixels very white at full power, had to cut it back to at 60% as full brightness is eye watering lol

    I find strips seem to drop a bit more power over distance though (depending on quality) but 5m/150 pixels on 5V or 12V is easily good enough when powering from both ends.

    For the power supplies, go with the largest and least number you can afford. Reason being, not only is it easier to wire, you will achieve better power efficiency.
    Last edited: Sep 12, 2017
  5. Grant Astley

    Grant Astley New Elf

    Oct 11, 2017
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    Dubbo NSW
    Doctor_007 I am not sure I agree with you on you voltage vs power statement, voltage has nothing to do with power, power is determined by what LED you are using. A more correct statement may be that generally speaking a 5v pixel/LED will have a lower wattage (I have not checked this either) the advantage of 12v over 5v is that you can run a greater distance without power injection as said previously. Personally I will be using exclusively 12v yes they may be of a higher wattage however you can dim/reduce the current going to them, and then you get the advantage of the 12v distance with a similar power consumption.
  6. Camknox

    Camknox New Elf

    Nov 22, 2014
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    Power = Wattage

    I'm sure Doctor_007 was using a colloquial reference to avoid confusion.

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