changing polarity

[Anonymous]

  

 

      i have  a G scale DC layout in my back yard that has a loop at each end that is connected with a single track connecting the two loops.  I know at a certain point i need to change the polarity coming out of the loops to get the train to run continuously around the layout.  what is the best way to get this accomplished? Did i create a big problem by making a layout like this?

[Rex in Pinetop]

Traderjoe,

What you have done is called "reversing loops".  The best way to handle them is with battery powered RC.  However if you wish to stay with track power then you will need to isolate a portion of the loops, install some sensors to detect when your train has intered the loop, and then a switch to change the polarity of the main line between the loops.  You'll need to do this on both ends so expect to pay some bucks for the switches and sensors.  The isolators are fairly inexpensive.

Rex

[altterrain]

A couple of articles on it -

http://www.realroad.com/TPW/RevLoops.html 

http://www.girr.org/girr/tips/tips3/reversing_tips.html#loops

-Brian

[spikejones52002]

I never understood why they called it a "WYES".

Think of it as a "TRIANGLE".

The wiring would make you think of going to battery power. Which has just as many limitations.

You will need to isolate the feed track to each switch. You will be changing polarity two times.

Wyes also limit the number of cars you can pull.

The maintenance factor increases greatly.

[two tone]

Hi Traderjoe, I may have found what you are looking for  it`s in the LGB cat part num 10151 or 10152 not for use with multi train systems.   Hope this helps

[dwbeckett]

You can do the electical switching with one dpdt switch.