connecting multiple 12v 5mm bulbs to 1 power supply

Discussion in 'The Projects Forum' started by aqw8326, Dec 14, 2012.

  1. aqw8326

    Thread Starter New Member

    Dec 14, 2012
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    I want to light my christmas village, so I got 12v 5mm whipe bulbs and 1 8xAA battery case, the bulbs are prewired with resistors.
    I have 32 houses that are on diffrent levels, do I connect all the black wires together, or should I run then red to black to red, etc.
    aqw
     
  2. aqw8326

    Thread Starter New Member

    Dec 14, 2012
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    That's white bulbs
     
  3. wayneh

    Expert

    Sep 9, 2010
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    All in parallel, black to black, not red to black. Each needs 12V, and putting them in series would reduce the voltage. You might want to use this for a few of them, where you want less brightness.

    Are these LEDs? If not, you'll need to be sure the batteries can keep up with all of them. Even with LEDs you may need 32 x 20 = 640mA. That's OK, but "high" and the batteries won't last more than a few hours on a charge.
     
  4. aqw8326

    Thread Starter New Member

    Dec 14, 2012
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    Because they are so spaced out, can I connect 3/4 black wires to a splitter wire, then all the splitters to the power supply, or should I solder longer wire to each?
     
  5. spinnaker

    AAC Fanatic!

    Oct 29, 2009
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    Those LEDs aren't going to last very long on 8 AA batteries. You would be better off with a small power supply. You can use a wall wart supply.

    You will need to limit the current in some way. The easy way to do this is with resistors but that will only add to the load on the batteries. so with the batteries, you would need a buck regulator.

    But you are over thinking this.


    Why not just buy a string of LED Christmas lights and be done with it? I used to light the houses in my model train platform with Christmas lights. It works fine.
     
  6. wayneh

    Expert

    Sep 9, 2010
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    A "bus" topology is fine and the LEDs don't care about the length of the wire used to connect them to the bus.

    BTW, I'm with spinnaker on this one. Get a string of lights ready made. Very low cost per light. They usually have a built-in fuse even. There are even battery-powered strings if you need that.
     
  7. aqw8326

    Thread Starter New Member

    Dec 14, 2012
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    I appreciate the help. As to the string of lights, I have about 12 strings, houses can't sit on them, the spacing is all wrong, and I don't want lights around the houses, just inside.
    I'll get to work now,
    Thank you.
    aqw
     
  8. spinnaker

    AAC Fanatic!

    Oct 29, 2009
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    The way I used to do it is to wire the lights under a platform, unused lights were hidden. Perhaps your configuration does not allow that.
     
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