# Advice on non-standard auto reversing configuration



## Trevor (May 8, 2012)

The first diagram (A) bellow is part of our current layout, the part not shown just completes the loop.
We want to add the ability to turn our locos around (with a without trucks attached) without having to actually pick them up and turning them around. Im after advice on the wiring for an auto reversing section, in particular which part of the layout to make auto reversing and whether it really necessary for the section to be bigger than the longest train (our longest train is 4m).
data:image/png;base64,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
At the moment I am thinking diagram C is the better option as it can accommodate a 4m train in the auto reversing section when switching in either direction, but I will need to position the double track gap near the 8ft circle so that the head and tail of the train are not both in the auto reversing section.


----------



## CliffyJ (Apr 29, 2009)

Trevor,
I'm using the PSX-AR unit from DCC Specialties, so I can only try to speak from that point of view, and attempt to put things in terms I understand. Your unit and its method may well vary.

The PSX-AR manages the DCC phase (not polarity) of the loop it is connected to. And when ANY metal object (caboose, loco, a dropped screwdriver) spans the insulated gap between the mainline and the "managed" section, the unit brings the DCC phase in line with what it has just been connected with. 

Cliff


----------



## Dan Pierce (Jan 2, 2008)

Any metal wheel crossing the insulated gap will cause a problem. 
And a caboose if lit really has front and rear axles wired together thus acting just like an engine for a short to activate the reverser. 
So, you need the isolated section to be longer than the longest train when using metal wheels.


----------



## CliffyJ (Apr 29, 2009)

Trevor, 

Given your 8' loop and 4m train, it looks like you may be able to squeeze a 1 train length managed section out of the right side of the loop. Is that possible? 

Another thing, were you hoping to throw your switches automatically with the auto-reverser? If so, you need a little extra distance between insulated gaps and switch points, to give time for the switch motor to operate when triggered via the gap. 

Cliff


----------



## High Ball John (Jan 26, 2009)

The easiest way to do what you want, but probably not the cheapest, is to have two auto reversers, one in each loop at either end of your layout.


----------

