Two rail reverse loop

Are you using Command Control such as DCC or just DC?

So for the present I have only the MTH Z1000 as a control system but I will incorporate a MTH TIU when I get my next locomotive.  That will also be a MTH product.  I believe that means, conventional now but DCS later this year.

Since you are using AC track power reverse loops are simpler because polarity does not determine the direction the engine runs. I used ASX AR-AC Reverser boards for the 4 reverse loops on my layout. Here is a picture of one wired into the layout.

Mark,

Ok I have read that article several times and have not fully digested its info. More questions.   Since I will be incorporating 2 train operations in the future, and want to wire for that situation,  I’m confused about a couple things:  What determines using a D2T 2w vs 3w relay?   I assumed a 2w cause it’s a 2 rail.  Does not the MTH Z1000 put ac power to the 2 rails?  If 2 trains are running at the same time, when the IR detector swaps polarity as the first train is emerging from the loop, how is the other train isolated from the swap of polarity?  I'm close but not quite there yet

Jim

I have been doing DC wiring for 55 years and the most lucid explanation of how to do reverse loops (and DC block wiring in general) is in the Kalmbach book "HO Primer" (surprisingly).  Each cab needs 2 DPDT switches (loop/main).  No relays or electronics unless you want to automate things.  I know am really old-school (see pictures) 

John

Tom,

Found a PSX  AR AC reverser on Tony’s Trains.  can’t locate your version, but assume it just a newer version.  Recomendations?  Is there a track wiring diagram for this understandable By a simple man.

Jim

John ,

Where do you park the Starship!   Now that’s a control panel.  I want to start with electric powered turnouts for now.  I ‘ll look for a copy of the book, I wondered if HO wiring is the answer.

Jim

DC wiring doesn't really care about scale.  The concepts are still the same, just use heavier wire for the O-scale blocks.  I still run some of the old series-wound motors in "boat-anchors", drawing current up to 6A, thus I use 14AWG for my blocks.  If you have newer equipment that may be overkill.  Switch motors (e.g. tortoise) can get by with 22AWG (save on copper).

John

Jim is using AC track power with conventional and command control, not DC or DCC.

The AC reverser board I pictured is 4 years old so the newer ones may look different. Wiring is really simple, power wires from the transformer in, power to the isolated block out. All the board does is detect a momentary short circuit if the the "polarity" of the reverse loop does not match that of the track the engine is coming from or departing to. A small spark is visible if you closely watch the engine cross the insulated track joint. The board then almost instantaneously flips the connections to the isolated section of reverse loop track it feeds.

I run both conventional and Legacy on this S gauge layout. These boards work so well the reverse loops are invisible to the operators.

John, that is a fantastic control panel!!! I bet it makes running trains on your layout really fun. I always liked large, complicated control panels. For the first time I have a layout with no control panel at all. I just have an iPad with some mimic screens and touch the spot in the track plan I want to actuate. I had great concern taking this approach but in retrospect it is working out great.

Jim, I have the books on HO 2 rail. Many years ago I had HO layouts and did some of this control wiring for DC layouts. It gets complicated when there are multiple reverse loops on DC layouts. For AC layouts w/o reverse loops the only difference between 3 rail and 2 rail layouts is the power to the turnout frog has to be switched  when the turnout is thrown. Gilbert did this inside the turnouts for American Flyer. When you use Tortoise machines, which I have, a relay can be used to perform this function. When adding reverse loops in 2 rail AC just insulate both rails at 2 points somewhere inside the reverse loop and power the insulated section through the reverser board. Done!

I have posted some of the wiring diagrams for the turnout points, position monitoring and for controlling DZ2500 switch machines. If you search on my name these posts with the diagrams will show up. Some of these get a little complicated because the power supplies for the relays and indicators are separate DC sources.

Tom ,

Thanks for sending me in the right direction, This forum is priceless!  Am I correct in saying that the switch controlling the turnout is wired independent of the reverser?  I can see only in/out wires and 2 black jumper wires.

AmFlyer posted:

Since you are using AC track power reverse loops are simpler because polarity does not determine the direction the engine runs. I used ASX AR-AC Reverser boards for the 4 reverse loops on my layout. Here is a picture of one wired into the layout.

 

I think the “ASX AR-AC” is likely a typo, shouldn’t it be PSX AR-AC? If so, they are available through Tony’s Trains website. They also have a similar unit for DCC rather than AC power. I have the DCC version and it works well.

Bill in FtL

Yes, the turnout controls are wired separately. I sure hope I am correct that you are using AC track power from your Z1000. If you ultimately install a DCC system it works basically the same as the AC system but the circuit boards are different. I have only tested these boards for compatibility with Legacy. I have no experience with the MTH DCS control system.

Bill, correct, I am embarrassed. I typed it wrong more than once.