Discussion in 'DCC & Electronics' started by lester perry, Apr 16, 2008.

  1. lester perry

    lester perry Active Member

    I usually get decoders from one shop. But a shop closer to home has started carrying DCC but he is not very knowledgeable. The first shop supplied resistor for lights the new one doesn’t. I need to know what to get for the lights to get from 12v to 1.5v , a radio shack number would be nice as I know very little about electronics,
  2. TrainNut

    TrainNut Ditat Deus

    If no one else replies with an answer to your dilemma, PM Woodone. He would more than likely be able to help you with that.
  3. Gary Pfeil

    Gary Pfeil Active Member

    Or do what I do: I have resistor values on hand in increments of about 100 ohms, starting near 60 and up to 1100. I start at the high end and work my way down, using whatever value lights the bulb.
  4. lester perry

    lester perry Active Member

    I think I found it in doing some reading, I came up with 1 ohm. Hope this is right
  5. beamish

    beamish HO & Steam Engineer

    1 Ohm is NOT correct. That will either fry the decoder, the light, or heat the resistor up so much you melt the loco. You should be using something like 1k(1,000) ohm 1/4 watt resistor.
  6. woodone

    woodone Member

    Not 1 Ohm!!!!!

    1 ohm will not work-- a blown light bulb for sure. :eek:
    1k (or 1000 ohm) a good place to start- I would think that 750ohm would do the trick.
    The new book on DCC has a chart on resistor valuues for DCC.
  7. b28_82

    b28_82 Member

    I personally use 560 ohm 1/4 watt because it's still below the threshold and provides a desirable amount of brightness
  8. 60103

    60103 Pooh Bah

    Lester: can you read the coding on the resistors you have? there should be a series of coloured bands around it. If you give us the colours, someone here will be able to translate it.
  9. woodone

    woodone Member

    VOLTS and AMPS

    To get the proper resistor for your lights you will need to know the voltage of the light and the amount of current that it draws. Most likley will be in milliamps for the current draw. Like 15MA or could be 60MA.
    You could hook up a 1.5 volt battery to the bulb and hook up a multimeter inline to read the milliamps. That way you would know what kind of amps the bulb is using.
    What we are doing is to use Ohm's law--R=E divided by I or I =E divided by R or E= IR
    R is resistance I is current and E is volts
    Hope this migh help
  10. lester perry

    lester perry Active Member

    Well I just bought some 1k ohm resistors at Radio shack. I will give them a try and let you know how it works
  11. Harold Cole

    Harold Cole Member

    Les, the 1 K will work.If the lights are not brite enough you can use 750 ohm resistors.I use the 750 resistors with the 1.5 volt LED's and they work just fine.

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