to DCC or not to DCC - that is the question

Discussion in 'FAQs' started by bobrien, Apr 16, 2002.

  1. RI541

    RI541 Member

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    Well the wife sent out the black robe thingy to get cleaned so I guess I cant scare anyone tonight.

    But I still am wondering about the reversing loop with DCC. I realize that your controlling the loco speed with the DCC but the reverseing loop causes a short in the track. So do you wire the loop the way you would with the blocking system?
  2. kettlestack

    kettlestack Member

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    OK robert, Hmmmm, thinking here.
    Thinking about the systems which use DC on the tracks, they would need blocking (MRC dc system has auto reversing modules).

    Errol

    Attached Files:

  3. Bob Collins

    Bob Collins Active Member

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    I just finished wiring my DCC so, although I am certainly no expert, I can tell you what I did. There are several ways to handle a reverse loop with DCC. I think I probably took the easy way out, but very effective. Cheap, no, effective, very.

    I have two reverse loops on my layout. First of all you must isolate the loops just like you would with dc. I used a Tony's Train Exchange Power Shield Auto-Reversers Circuit Breaker. When the first wheels of the train cross into the isolated zone the circuitbreaker instantly sets the polarity. No dpdts to mess with, all automatic :D :D No question is would be cheaper to use dpdt, but I thought that since I was mainly going to operate alone it would be much easier to have the situation taken care of automatically, especially since the loops are on opposite sides of the layout.

    So far so good.

    Bob
  4. 60103

    60103 Pooh Bah

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    DCC reverse loops

    My friend with the DCC layout uses one of those electronic contraptions to automatically polarize his reverse loop (and his turntable!)

    My idea would be to wire it through a set of DPDT contacts on the switch machine. After all, you do have to throw the switch sometime when the train is in the loop.

    Sometimes when we have mysterious short circuits the gizmo clacks away for a while before the whole layout shuts down.
  5. Woodie

    Woodie Active Member

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    Re: DCC

    Robert,

    Little gadget thingies that you can get for DCC will sort your reversing loop out for you. "A reversing loop box". It detects the loco as it enters the loop, and switches polarity automatically and the decoder sorts it out too, so there is no need to stop, swtich polarity switches, then move off again. Totally transparent to the user of the cab control.
    As far as running two (or more) locos, you can just leave the loco wherever it happens to be, and drive the other, even if they are only 2" apart! Even in a loco siding (you may have all you locos in one siding), you can drive each one individually, without having "blocks" set up down the siding.
    When you "set up" a DCC loco, you tell it "this loco is number 42" (or whatever number/name you want). Then, on your cab controller, you select "loco 42" and then drive it. Switch to "loco 77" (or use another cab controller) and then drive that, while "loco 42" is still trundling round the track. Switch back to "loco 77" and slow it down..... or whatever. The DCC system puts computer commands through the tracks. Each time you move the speed control on the cab controller, it generates a computer command that says to the tracks "loco 42 go at speed 100". The decoder in "loco 42" picks up this command, and applies the amount of power necessary. Because this command is for "loco 42" ONLY, all the other locos on the track ignore the command.

    Voice activated? Sure.... it can be done right now, if you want.
    DCC systems have the ability to just plug straight into your computer as well, and you can have you computer generate the commands (just as the cab controller does). You can already get software that will drive DCC systems from your computer. So you can sit at your computer, and have a "slide control" (just like a volume/speed thing) and use you mouse to move the slide up and down to control the speed. One slide control on the screen for each of your locos. Just imagine, your layout diagram on your computer screen, with indicators where your trains are, and just "click" on a junction in your diagram to switch the turnout. "click" on "loco 42" and the whistle sounds.... "Click" on another icon and a platform announcement is made etc etc etc. The possibilities are limitless. The hardware/components to do this all exist TODAY.... yep... NOW.. with DCC, it's just the software for your computer that needs to be written, and if your computer skills are up to it, then there is no reason why you could not write the programs yourself.
    Voice recognition software is available, and if you know someone who can write a pooter program, all they have to do, is write a program that generates the computer command "loco 42 go at speed 100", when it recognises your voice. Or you may say "TOOT", and the computer program will generate the command "loco 42 sound whistle". The technology exists. It's just a matter of someone writing a program to utilise it all.

    The mind boggles!:eek:

    I'm not pro/against DCC etc, however DCC allows you to do this sorta stuff should you want to do it. You don't have to do it.
  6. Gary Pfeil

    Gary Pfeil Active Member

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    Woodie, Thank you for that last line! Yes, DCC can do all you say and more...Digitrax decoders now have a feature they call transponding, which is basically instead of the decoder receiving and acting upon signals from the cpu, it also can communicate back. The data it sends is its address (usually the cab #). This data is connected to your computer and you can have a schematic of the layout on your puter, with all blocks identified, with signals and turnout control with a click of a mouse, and the dispatcher seated at the puter will see where every train is. I'm not sure why this appeals to people, but to each there own. Use the functions of DCC that match the era you're modeling and that your skill level permits. Those such as Woodie, proficient with computers, can have a field day and a lot of fun. Others such as myself can be satisfied with simply the ability to run locos wherever and at whatever speed desired without flipping or turning a single block control switch. Light control is another plus. The sound units are actually pretty awesome. I've always been a hi fi nut and the previous sound systems available sounded pretty lame. Still, there is only so much you can do with a 1" speaker, but the response is pretty good. Imagine your current day diesel hauling a stack train and approaching a grade crossing. You press a button on the throttle, the horn blows and ditch lights start flashing. Or a mars light on an E unit. The sound of simmering steam. Anyway, in my opinion the most important feature of DCC is elimination of those block switches, enabling you to have engine ready tracks without gaps amoung other things.

    OLDGATORBOB: Others have already answered your question on reverse loops. I will only add that my experience with the MRC reverse unit was not so good. They seem to work ok with the newer diesels, but not with steam or older diesels which do not pickup power with all wheels. These diesels are mostly best off on a shelf if you really cherish them, donated to someone if not. But I run a lot of steam, and the pilot wheels would not trip the MRC unit. Tony's unit works fine. (www.ttx-dcc.com) When I bridged the gap of a reverse block equipped with the MRC unit with a screwdriver, the polarity would not change. My rather unscientific conclusion is that the MRC unit requires some current draw to be present in order to change polarity. Not so with the Tony's unit.
    You mention 5 blocks on your point to point layout. Realize that the number of blocks you require with DCC is determined by the best way to troubleshoot for a short. You will only be turning blocks off to see which block has a short. So every place you would like to be able to store a loco doesn't have to be a block like staight DC. You can choose to install a spst toggle to each block you create and install it out of the way, or circuit breaker type modules similar to the auto reverser which will shut down just the block with the short, not the entire layout.

    Good luck, Gary
  7. Bob Collins

    Bob Collins Active Member

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    Woodie;

    What you are talking about is exactly what I have done, identified my loop (NOT at a turnout, or at least not wired in with a turnout) isolated it, and installed a reversing circuit breaker that detects the train when it comes into the loop. You don't have to do anything else, it is all automatic. As I said before, I did it this way (a bit more expensive) because my loops are on opposite sides of my layout and I basically operate alone and don't want to have to break my neck getting to the other side to throw a dpdt switch.

    Bob
  8. IMRL393

    IMRL393 Member

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    I'm jumping in late on this one - just three remarks:

    1. If you get a system with 4 digit addressing, there are no numbers to "memorize" - the road number on your loco is the number you can use!

    2. If the RI group was a cult, we would be trying to "convert" you away from all those minor roads (like UP, AT&SF, etc.) you seem (for some reason) to like. We are not a cult - we are an elite, and so are above such things!

    3. DCC system to look at - one word: Zephyr !

    Due out this summer for the price of one good (Atlas, P2K) loco.
    See Tony's Train Exchange for details (be sure to see the extra info about the system at the bottom of the TTX web page):

    http://www.tonystrains.com/technews/digitrax_decoder_wars.htm



    - George
  9. Bob Collins

    Bob Collins Active Member

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    George;

    Maybe those modeling the RIL are not a cult, buit dealing in the ocult, that is dealing with something that really isn't there except in your minds:D :D :D :D :D

    I just learned while doing some reading the other day that the RIL was the first railroad to come to Council Bluffs, late in the 1850's. That was, of course, where Abraham Lincoln visited in 1859 and declared Council Bluffs the eastern terminus of the transcontenental railroad. Later there would division points for eight railroads there in CB, which is the environment I grew up there in and the love of trains has never dimmed!

    I believe it was on the same page where I saw the ad for the book of 600+ pages covering all of the wrecks of the RIL -- 600+ pages--- wrecks---RIL---WOW:rolleyes: :rolleyes: :rolleyes:

    Bob
  10. Gary Pfeil

    Gary Pfeil Active Member

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    George, I was just reading about the Zephyr the other day. It really looks like an entry level system I would recommend. The seperate programming track is a major plus. I don't remember if it supports ops mode programming readback. I think it did. This is a feature people will appreciate when programming sound units. Also speed matching. Being a "console" type unit, it should be more comfortable for those switching over from power packs. While I still would recommend the chief to those who can fit it in their budget and expect to be in the hobby for some time, the Zephyr seems ideal for those who need to spend as little as possible.

    Gary
  11. OLDGATORBOB

    OLDGATORBOB New Member

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    DCC............................

    OK,GUYS THANKS A LOT FOR THE INFO.
    IT LOOKS TO ME LIKE YOU CAN GET INTO THIS ABOUT AS DEEP AS YOU WANT. SOUNDS GREAT TO ME........
    I FORGOT ABOUT A TUNTABLE. AS FOR THE PC SET............ I CAN'T EVEN WORK THIS THING NOW, I WOULD HAVE THE ONLY "FLYING LOCLS" IN TOWN. I STILL THINK I AM GOING TO GO WITH DCC WHEN THE TIME COMES.
    YOU ALL SURE HAVE BEEN A GREAT HELP.

    THANKS TO EVERYONE, ROBERT

    P.S... I WELL KEEP CHECKING THIS THREAD FOR MORE INFO.
    HERES ONE.... WHY DO THEY CALL THIS A THREAD?????

    SEE EVERYONE LATER, JUST GOT BACK FROM THE VA HOSPTIAL ABOUT MY SORE FEET, I HAVE SUGAR REAL BAD, I HAD TO DRIVE 140 MILES ONE WAY TO SPEND 20MINS. IN THE DOC'S. THEY SAID TO STAY OFF OF THEM, SO I GUESS I WILL GO BACK AND LAY SOME MORE CORK...... STANDING ON MY FEET.
    THEY DON'T SEEM TO HURT WHEN I AM RAILROADING. THE DOC SAID...........
    BULL!
  12. RI541

    RI541 Member

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    George,

    Does this mean I can put the black robe away? Darn I just spent half a day sewing the big red RI hearld on the back.

    You are right, us RIL guys are the ELITE.

    I guess that the UP,ATSF,BN or others never derailed,Oh well maybe when they grow into big roads they'll understand.
  13. Woodie

    Woodie Active Member

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    Re: DCC............................

    Robert,
    How long is a piece of string??? :) :) Perhaps "posts" should be called "knots" :D :D


    BTW.... One of the main reasons I like model railroading, is that it can encompass many hobbies in one. Electronics, computers, photography, art, scuplting, researching history, travel (looking at protypes), imagination (freelancing), carpentry, relaxation, amusement, communication (such things as "The Guage") etc etc etc..... It's not necessarily just the trains, themselves. You can partake in all, some or none of these, at your own choice. :cool: I don't think there is another hobby that can encompass a wider range of choice or things to include/exclude. :)
  14. YakkoWarner

    YakkoWarner Member

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    Woodie, I race shifter Karts and, except for the carpentry, that hobby encompasses all of things as well. And the expense actually fits in just below the G scale trains.

    My wife has decreed that if I want a garden railroad I will have to give up either the motorcycle or the shifter kart. I don't know that I can do either:D she has gracefully allowed me to design the kitchen dinning room to include a train theme in a Mission architectual setting.

    She thinks I will give-up the space set aside in the spare room. :rolleyes: