Re: Where to isolate on large loops and wye



Re: advice concerning minimum length of fixed polarity track segment between AR segments:  I have not found any advice either.   


Maybe a subject for a follow-up article?

Bill D
N&W Steam Only

On Feb 25, 2021, at 9:47 AM, whmvd <vandoornw@...> wrote:

Hi Don,

That 'short' piece of track linking to AR sections does raise the question 'how long at least?' immediately. My first thought is that it should be at least as long as the maximum (outer) distance between axles that pick up current on the longest individual piece of rolling stock - but I could easily be wrong, and it gets even more complicated with staggered pick-ups. Is there any guidance on this somewhere? If so, I've not found it.


On Thu, 25 Feb 2021 at 14:25, Don Vollrath <donevol43@...> wrote:
Good description of AR, Bill.
Some may argue with the need to have the AR section longer than the train only to get caught later with problems when using lighted passenger cars or a lighted caboose or a following helper loco. 
If two AR sections abut one another there can be a never ending cycle of both AR controllers detecting a phase mismatch and flipping the polarity only to find a mismatch again and repeating the cycle. A simple fix is to provide a short section of track between them wired at a fixed polarity. 


Join to automatically receive all group messages.