Bettery Replacement

Discussion in 'The Projects Forum' started by ytmystic, Feb 2, 2007.

  1. ytmystic

    Thread Starter New Member

    Feb 2, 2007
    Hello, I am currently working on a model railroad layout, and need to find a better way to power an EOT device. Currently the LED circuit runs off a AA battery. When I use a Duracell Ultra, the battery is drained within a week. What I am considering is using a module to replace the battery, pulling a charge from teh 8-16v track power. My problem is what the best setup is for this. I would like the have the charge hold for at least 30 minutes, optimally though for a few hours. Any suggestion would be great. Oh, and the lighter the better on weight. Preferably no more than one AA battery

    Thanks in advance

  2. thingmaker3

    Retired Moderator

    May 16, 2005
    You might want to consider an LM317 adjustable voltage regulator with a heat sink. Two capacitors and two resistors will be the other components. (You'll want a 5:1 ratio of resistance to get your 1.5vdc regulated output.) Total mass should be about the same as your AA, depending on the heat sink. Note: this will produce a couple watts of waste heat - I don't know what kind of ventalation you have on your models. I have seen some very tiny motors, if you can sculpt a fan blade.

    A quick internet search on "LM317" should give you some pdf documents with all you need to know.
  3. mrmeval

    AAC Fanatic!

    Jun 30, 2006
    Can you get continuous power to that from the track? If not were you looking for a rechargable battery system?
  4. ytmystic

    Thread Starter New Member

    Feb 2, 2007
    Currently, The layout is set on a timer, which runs for 2 hours, then breaks for 30 min, during the day, then over night it is off... which I don't need a charge to last for much. I had considered trying a rechargable system, but all the chargers I have seen pull from a 110/120 wall outlet, and are just too large for teh moving train.

    It would be easy to "vent" the container that this is in, but I would probably need a fan to do it, and that may add a bit of weight.

    I will look at the PDF's and see if that will work :)

    I'll let you all know if it works as well.

    Thanks a Bunch!