UPS for decoder

Discussion in 'DCC & Electronics' started by MasonJar, Jan 30, 2007.

  1. MasonJar

    MasonJar It's not rocket surgery

    I have a brass Mack Railbus that only picks up on the two rear drive wheels. Suffice to say it does not like insulated turnouts.

    I have explored the idea of an Uninterruptable Power Supply (UPS) for a decoder. The only commercial version appears to be from Lenz, and they want about $60 for a Gold-series decoder, and another $60 for the UPS capacitor unit. :eek: I am a complete electrical newbie, but it seems to me that there has got to be a cheaper way to do this?

    Any thoughts? Diagrams? Shopping lists? Illustrated how-to's? ;)


  2. billwv

    billwv Member


    I, also, know very little about electronics. But, I think it is much more complicated than just adding a capacitor. There has to be a charging system to avoid current inrush. I also understand the Lenz system will not stop the loco on a spot if there is no contact there, i.e. try to find good contact before stopping the loco. etc.

    I have Lenz Gold decoders and they are excellent in terms of BEMF control and smooth slow speed. For me that makes them worth the extra cost.

    I have not tried the USP module. I have heard that slodering the module to the decoder pads is very difficult and should only be attempted by experienced techs.

  3. radar

    radar Member

    Could you put metal wheel sets on the front then use a wiper made from a KD #5 brass centering spring?
  4. MasonJar

    MasonJar It's not rocket surgery


    Thanks for the feedback on the Lenz decoders... I will enlist the help of an experienced solderer when the time comes...!


    I think that your proposal may be the easiest solution, but I would like to try the capacitor/UPS in part just so I can say I have done it... ;) Actually, it does look like the best solution to the problem, with the extra pick-ups being a close second.

  5. baldwinjl

    baldwinjl Member

    The capacitor/UPS solution really needs to be on the motor side of the decoder, not the track side, since putting it on the track side will corrupt the DCC signal itself. I don't know how the decoder output is going to react to the capacitor, but I think it should work, at least to a degree. I'll have to give that some thought. I'll write more later, if I learn anything.
  6. billwv

    billwv Member

  7. baldwinjl

    baldwinjl Member

    That capacitor is on after the rectifier, so it doesn't mess up the DCC signal. In most decoders, other than ones that are designed to allow it, you don't really have access to the place you'd need to put it.
  8. MasonJar

    MasonJar It's not rocket surgery

    Thanks for that link. Looks like I will either have to give up on the idea, or vastly improve my soldering skills and equipment...! But at least I know where to find the explanation if I care to attempt it. :)


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