Sensing, Signals and Auto-Reverse

Discussion in 'FAQs' started by kchronister, Jan 5, 2006.

  1. kchronister

    kchronister Member

    Well, it's official... Benchwork has started. As I move out of layout design and construction issues, new questions arise for which I don't have good answers. Three of them, specifically. I've reviewed some existing posts and none quite hits these issues head on:

    Behind this, two givens that are probably relevant:

    a) I run DCC. Specifically a Lenz System 100. I've had that for a few years now, and haven't really kept up on new DCC system/decoder developments. I've been happy with the Lenz, but given the magnitude of the project, if part of the answer is switching to a different DCC system, I'm open to that.

    b) I don't have a money tree, so cost issues are relevant. HOWEVER, I would rather do it right, even at more expense, than do it wrong. Only when we get to all-else-being-equal-option-X-is-cheaper does cost become the deciding factor.

    Now the Questions:

    1) Remote sensing.

    I have several hidden tracks where I'll need to control indicators showing where train is. Loads-in-empties-out setup, reverse loop, staging, etc. What's the best way to do this? I've seen remote-video setups, IR detectors, reed-switches, and so forth. I believe, but don't yet really understand, that recent developments in two-way DCC and new decoders allow this to happen via the DCC system too (could be wrong). Anyone have an opinion to share or real-world experience? Even pointing out a place that explains 'two-way' DCC would be helpful. Left to my own devices, I'd prefer a DCC option, then an IR detector, then video and avoidance of reed switches, but I'm by no means "decided."

    2) Auto-reverse/auto-turnout.

    I have several wyes and a reverse loop on the layout. I own, have used, and like Tony's Train Exchange auto-reversing controllers to handle polarity switching. But since one wye and one reverse loop are hidden under scenery, I'd really prefer a setup that sense the train approaching and throws the switch correctly. To my knowledge, the only way to do this is a Tortoise/Hare combo, which ain't cheap. I'd love to know about other options to accomplish this better and/or more cheaply (maybe via DCC???, maybe something else?) and or real-world experience using this setup.

    3) Signals. I'd like to build signaling into the layout. I have zero experience of this and it's one of the areas in the hobby of which I have the least knowledge. I vaguely know that some DCC systems (I think not Lenz) will handle this. I have a little basic understanding of how it would work in DC, but that's not an option. Again, tips on places to get the basics, advice, input, etc. are all welcome.

    Many thanks in advance for any information you can share, and your time in sharing it.

  2. Gary Pfeil

    Gary Pfeil Active Member

    Hi Casey, I can't speak from experience on these questions as I don't employ any of them on my DCC layout. However, I have thought about it, particularly the hidden track detection and signalling. So far I haven't been willing to part with the cash. Digitrax offers "transponding" which requires either one of their decoders which includes this feature or an add on decoder with just this feature. The add on is maybe $8. Then the track must be blocked in a sensible manner and after that things get a bit beyond my understanding, the layout can be connected to your computer and you can have a dispatcher know not only which blocks are occupied, but what loco (or rolling stock, if you equip them) is there. Obviously, this also will control signals. I'm not sure you need the computer for all these functions. Your best bet would be to first go to and read about it, then call Tonys and speak to Tony or Ken. BTW, I also use Tonys reversing modules, and they work great.

    For hidden track detection only, I have used a circuit from, must be 20 years ago. It uses a quad comparator and photocells to light leds on a panel. A light must shine on the photocells, when the light is obscured by a train, the led goes on. Relatively inexpensive, I built enough of these for 30 detectors (3 per track, entry and exit foul points, and one in the center) and that handles the staging yard at one end of the layout. I haven't yet built any for other staging areas, and haven't been in the mood to do all the work for some time now. I just look! It is the installing of lights that I don't care for, some areas have limitd overhead clearance. I would like to use the IR detectors offered, but talk about expense. I'll be keeping aneye here to see if someone has cheaper alternatives.

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