Varipower Heated Bed draw

Discussion in 'General' started by andyandyandy, Apr 1, 2016.

  1. andyandyandy

    andyandyandy Member

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    Hello, I'm in the midst of buying parts for a CoreXY-style printer, and decided to go with the same print bed as what appears in the BigBox (purchased from Filastruder). My question is, the blog post for the bed describes using a 400W 24V power supply, but I'd like to know if a 360W supply is enough. Everything else on the printer will be 12V so only the bed will be using the 24V supply.

    Thanks!
    Andy
     
  2. Kick2box

    Kick2box Well-Known Member

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    Mine has 2,4 Ohm, so should be about 230-240W.
     
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  3. andyandyandy

    andyandyandy Member

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    A 15A/360W supply should be plenty, then. Thank you!
     
  4. elmoret

    elmoret Administrator

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    Using a recently calibrated Fluke 179 multimeter:

    After subtracting for the lead resistance of the multimeter, bed resistance at the crimped cable end is 2.1 ohms at 18C and 2.2 ohms at 30C. Resistance will continue to increase as a function of temperature, so the peak load on a power supply would be about 11 amps.
     
    #4 elmoret, Apr 1, 2016
    Last edited: Apr 2, 2016
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  5. andyandyandy

    andyandyandy Member

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    Much appreciation for the detailed answer, thanks! Maybe it is worth the extra money to go up to the 20A supply.
     
  6. Kick2box

    Kick2box Well-Known Member

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    Is there a certain reason to choose 12V for the rest of the printer? I suggest you better use 24V for everything.
     
  7. andyandyandy

    andyandyandy Member

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    Originally when I started getting parts I went with one of the readily available & cheap RAMPS kits on ebay, which afaik can't do much past 12V. If I were to go all 24V I'd need something like a Taurino Power board and a 24V heating element for the hot end, right?

    Edit: Oh and fans, would need 24V fans.

    Why do you recommend all 24V power?
     
    #7 andyandyandy, Apr 4, 2016
    Last edited: Apr 4, 2016
  8. Kick2box

    Kick2box Well-Known Member

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    I was just curious why someone wants 24V for the bed and leaves the rest with 12V. As it's not so difficult to use a RAMPS with 24V, I will not give such a long answer myself, read here instead, there's an answer to almost every question: http://forums.reprap.org/read.php?219,196602
     

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