help me I am eager to finish....

Discussion in 'FAQs' started by Union Pacific, Oct 22, 2005.

  1. Union Pacific

    Union Pacific Member

    I have decided to finish a project :p :rolleyes: ;) I have an Athearn SW-1500 that is undecorated I want to add ditchlight and directional lights I am using DC. I have some 12V micro lamps I bought from Radio Shack. I want to make the fromt ditchlights come on witht the front lights and the back ones on when it goes in reverse. I can't figure out hoe to get the dumb thing wired I knowhgow to solder and wire the motor insteaad of using the dumb clip:curse: but I want to put a resistor on the motos so the light light up a bit before it moves I hev tried tinkering with it but couldn't get anything to work:mad: :curse: I hope you can help

    Thanx, Ben
  2. doctorwayne

    doctorwayne Active Member

    The circuit that you are looking for is in the November 1979 RMC, page 64. This is an easy circuit to build, since even I have built one. Basically, get a piece of copper foil board from Radio Shack, along with eight one-amp diodes such as 1N4001 (Radio Shack part 276-1101), two 1.5 volt grain-of-wheat bulbs for the headlights and some suitable 1.5 volt micro-miniature bulbs for the ditch lights. Cut a piece of the foil board to fit the width of the hood and make it long enough to allow you to mount four diodes on it, end-to-end, with a little extra length to allow for insulating gaps. Using a pencil to mark the foil side of the board, divide it along its length into five sections: what you need to do is drill holes through which to mount the diodes, four up one side, all facing the same way (either the pointed or striped end) and four down the other side, all facing the opposite direction to the first four. Before you solder the diodes to the board, use a file or a cut-off disc in a motor tool to cut insulating gaps in the foil. There should be a gap completely across the board so that each diode's leads are separated by a gap. (Looking at the board standing on its narrow end, the bottom section, one, would have two holes in it for the one lead of the first diode in one direction and one lead of the last diode in the opposite direction. The next section, two, would have the leads on the other end of these two diodes, plus one lead from each of another bi-directional pair of diodes. The third section would have the opposite ends of this pair, plus one lead each of the next pair. The fourth section, the other ends of this pair, plus one lead each of the next pair. The fifth section is for the leads on the other end of the last diode pair. The sections at both ends require one extra hole each: solder a wire to one from the power source, and from the other to the motor. In addition, an insulating gap needs to be cut in section four to divide it along its length so that the leads from the diodes facing "up" are isolated from the leads in the diodes facing "down". For any lights that are to be directional, connect one wire to section two, the other to one side of section four. The corresponding light for the opposite direction connects to section two also and to the other side of section four. Any lights that are to be on in both directions, connect one wire to section one and the other wire to section three.
    I hope I've described this adequately: if you can find the article, the diagrams are much easier to understand. And the circuit does work, although I've given up lights in exchange for more weight for added traction.
    You might be able to get a copy of the article from RMC: doesn't hurt to ask.
  3. LisaP4

    LisaP4 New Member

    Try this link, it should be what your after.
  4. Union Pacific

    Union Pacific Member

    :eek: :eek: thank you for the info and that site I will use the site Doctor since I don't have that MRC ishue and I am one of those"lemme see the picture" person ;) I will post my progress I have 4 litle lamps I got at radio shack that are rated at 12V so they should work if I somehow resist yhe current to the motos before the lights light up.

    Thanx, Ben
  5. Pete

    Pete Member

    Hi Ben
    You'll need more than just resistors to make the lights work directionally; the diodes in the circuit shown in the link above act as one-way 'valves' to let the current flow in only one direction; resistors alone cannot do that. That circuit is the same one that Life-Like uses in many of their P2K locos, and it works perfectly.
    Another option would be to use LED's and resistors instead of the bulbs. These have at least three great advantages; first, the LED has a built-in diode, so it only lights when current flows in one direction; They have an extremely long lifespan - up to 10 years of constant 24/7 usage; and, they don't get hot like an ordinary light-bulb does so you won't melt or distort the plastic shell.
  6. Union Pacific

    Union Pacific Member

    I realize this know and I am going to use the alternating ditchlight curcuit ,directional light circuit, and 5 volt supply circuit on that site. I will try and fit all this into the cab and above the motor I will post my progress once I get some components ie.diodes,rectifiers etc.

    thanx, Ben

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