Power supply for DMX to LED driver/decoder

Discussion in 'The Projects Forum' started by clearmotions, Sep 30, 2014.

  1. clearmotions

    Thread Starter New Member

    Sep 30, 2014
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    Hi, I'm somewhat new to DIY electronics projects and could really use some help with a stage lighting project that I am piecing together.

    I'd like to take this USB/DMX interface and make it communicate with an RGB decoder like this one. However, making them talk to each other is the easy part for me. My biggest question is how would I go about ensuring that I have the correct type of power source. It lists "DC9V-DC24V" as its input power. I am just wondering what kind of DC supply I should buy and also if this would provide enough power for, say, five 7' strands of regular RGB LED. I see that there are four leads on the board for power supply but I'm not sure what kind of supply I would actually need to connect to it.

    Is there a way to calculate how much length of LED each channel could handle based on the input power?

    Sorry if these are dumb questions, I'm somewhat new to the hardware side of things. Any input would be appreciated. Thanks!
     
  2. #12

    Expert

    Nov 30, 2010
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    The RGB controller has a limit of 1 amp per channel times 30 channels. Leds can be had anywhere from .02 amps each to a whole amp each. This information is missing from your post. What kind of LEDs?

    This controller can distribute up to 30 amps, 1 amp per each of 30 channels.
    I'd say, 12V to 24VDC and several amps of capability, but that depends on your LED strings needs.
     
  3. clearmotions

    Thread Starter New Member

    Sep 30, 2014
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    Sorry, I knew there was something missing. Details below
    • Max 0.6 Amps per meter
    • Maximum 12V @ 60mA draw per strip segment
     
  4. #12

    Expert

    Nov 30, 2010
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    Well, there you have it. 7 feet is 2.135 meters and that's more than an amp.
    Now..if you can split the red, and the green, and the blue into 3 channels, you can make it work that way. Possible? Or am I just guessing badly?
     
  5. clearmotions

    Thread Starter New Member

    Sep 30, 2014
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    Yeah, that makes sense to me now. So I'm guessing around 24 watt and ~10 amps would probably be necessary to drive the entire setup at full white with full brightness (around 35 feet of LED).

    The decoder splits RGB and voltage into individual channels, which I was planning on routing into a patch bay. If I overestimate power draw (for the time being), do you think that the MOSFETs on the decoder will do fine with stepping down the voltage until needed?
     
  6. #12

    Expert

    Nov 30, 2010
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    That's 24 volts...not 24 watts. And, yes, the MOSFETs should step down the volts/amps/watts, that's their job.
     
  7. clearmotions

    Thread Starter New Member

    Sep 30, 2014
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    Whoops, that's what I meant. Ok, cool. I'll probably go with 24 vdc and 10 amps just to be on the safe side.

    Thanks for the help!
     
  8. #12

    Expert

    Nov 30, 2010
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    Do the math:
    35 feet times 36 inches/ft times meter/39.34 inches = 32 meters
    32 meters times .6 amps = 19.22 amps.
     
  9. clearmotions

    Thread Starter New Member

    Sep 30, 2014
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    Yep, going with two 10 amp power supplies and two drivers. I realized that the drivers with more channels have lower maximum amp input per channel so I had to split them.
     
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