Re: Can you power the frog on a turnout that controls an autoreverser

Vollrath, Don <don.vollrath@...>


For automatic operation it should be the other way around in that the auto-reverser should control the Tortoise. Then you simply need to wire up an internal SPDT switch of the tortoise to power the frog from the proper track rail as selected by the path position of the throw bar. How to control the Tortoise motor or somehow trigger it to change the throw bar position in time as needed to prevent a derailment is the better question.


But Yes… If you are using an auto-reverser connection to somehow control the Tortoise, you may need to move the location of the gaps needed to make the auto-reverser function further away from the turnout… depending how fast your trains will run. Also be aware that by definition the ‘frog’ is a relatively small object of the middle of the turnout. Some power routing electro-frog type turnouts run the electrical service tied to the frog and frog exit rails all the way to the end of the turnout. This can be problematic as the sliding switch contacts inside the Tortoise are not intended to carry the pulse of current necessary to trigger the A-R unit and the rails can become dead during movement of the throw bar. In that case you need to either make the turnout DCC friendly by isolating the frog, etc. or somehow establish a fixed polarity zone approaching the turnout that triggers the A-R unit and causes the Tortoise to start flipping the throw bar to suit… before any power pick-up trucks will reach turnout rails.




From: WiringForDCC@... [mailto:WiringForDCC@...]
Sent: Wednesday, November 02, 2016 3:39 PM
To: WiringForDCC@...
Subject: [WiringForDCC] Can you power the frog on a turnout that controls an autoreverser


How does one power the frog on a turnout that controls an autoreverser?  I am using tortoise switches and controlling the frog using the tortoise internal contacts. It appears that I must place the gaps well downstream of the return leg (prior to re-entering the turnout) in order to have the autoreverser trip before any of the train (let's say I have a lighted caboose) reaches the frog.  Is this correct?  If I cannot gap it well enough in advance, it seems I should go with an unpowered frog...

Ed Robinson


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