Both good points Pete and Rich.
Elmer.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
Elmer,
Very good explanation of the basic considerations of auto reversers and reversing sections.
One comment that i might add to this explanation is that any and all feeder wires to track in the reversing section should be wired to a separate set of bus wires, and those two bus wires should be wired to the output side of the auto reversing unit. By maintaining a separate set of bus wires for the reversing section, there will be no chance of mis-wiring the reversing section and no chance of causing unexpected shorts in the system.
Rich
Alton Junction
Very well said. There are adjustable auto reversers that work great with low amp starter sets. There are also ones with built in decoders that flip the turnout automatically with no input from the operator. The PSX-AR also can control a reverse loop inside a reverse loop. Advancements in DCC and track control is changing fast and research is needed with every purchase we make.
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
A little information about DCC auto reversing sections and reversers. When using DC, if you changed the switch under a moving train, the train would reverse directions. Thus, you generally had two switches. One to reverse the loop, and one to reverse the layout. In DCC, this does not happen. So as an example, if you have a reversing loop, only the loop would be connected to the auto reverser. You would not need to change the polarity of the main layout any more. When the train entered the loop, and the loop was not set right, the auto reverser would change the polarity of the loop to match the layout for the incoming train. When that train went to exit the same loop, the auto reverser would again change the polarity of the loop to match the layout. And when this happened, the train would not change directions.
Auto reversers also have an input side and an output side. The output side goes to the section that is to be reversed, such as the loop in the above example. The input side is wired to the DCC bus, the main track next to the reversing section, or the DCC booster output. Wiring the input to the DCC bus is the most logical choice for most folks.
Some auto reversers also act as DCC circuit breakers for the reversing section. Most of the electronic type of auto reversers do.
Some auto reversers do not work well with low current or beginner DCC systems. These systems do not have the current availability to make them operate correctly. So ask questions and do your research before purchasing an auto reverser for your DCC system.
Hope this helps.