Spring turnouts and power routing

[velotrain]

Tomix and Kato turnouts are sprung.  My understanding is that the benefit of this is it means a tram/train can cross through from the non-selected side without derailing.

 

I believe these turnouts are also power-routing, in the same manner as the Peco Electrofrog, meaning that if power is supplied from the single track side, then it will be directed to the selected track on the turnout.

 

What I'm not getting is just how these work together.  I can see how the spring action would be useful for trams when two routes merge, so you wouldn't need to throw the switch continuously for each line - depending on direction.

 

However, for this to work, does it mean that power needs to be supplied to both sets of rails on the back side of the turnout? 

 

Let's say the turnout is set for straight.  If a tram is approaching it from the curved track, it will not have power on the turnout unless it is supplied from behind it.  I trust this, combined with power on the straight track, will allow it to run smoothly through the turnout?

 

Is this correct, or am I misunderstanding?

[kvp]

Yes this is correct. I would add that Tomix turnouts are fully power routing, which means they have cuts in the outside rails too, so you can wire up a ballon loop by using a single turnout or select between two different polarities or even controllers by powering the turnout from both rails on the frog side only.

[kvp]

This is an example for the possibilities of fully power routing turnouts. Only the top right one is used as a sprung turnout, the bottom left and right ones are switched together, while the middle one is separate and used for route selection. The layout is powered from the bottom right, where the green line is. This way, it's possible to move a tram around the two ballon loops without stopping or to send it to the oval. The layout can be used with two trams at the same time, by parking them on one of the black unpowered sections while the other one is running. Here the turnouts are used both for power routing and polarity change, while using one spring action only turnout fixed in the diverging position. (the layout above is drawn using Tomix mini tracks)

[velotrain]

Thanks for the drawings and explanation kvp.

 

I'm not sure I understand this: " the bottom left and right ones are switched together".

 

The way you've drawn this, there shouldn't be any need for switching those two at all.

 

Also, it seems to me that the left one can be switched independently, to change the direction around that balloon loop, without impacting overall operation?

 

Switching the right one could modify the operation, depending which way the top right sprung turnout is set.

[kvp]

 

I'm not sure I understand this: " the bottom left and right ones are switched together".

The trick to maintain continous running on the left ballon loop is to switch the bottom right whenever the bottom left is switched. This way the polarity reversal of the left loop is canceled out by the polarity reversal of the mainline. This is needed because the polarity of the mainline is determined only by the bottom right turnout. They have to be switched, because the polarities on their two routes never match, so they can't be cut without causing a short. (personally i use a TCS sensor pair to drive the switches)

 

On the other hand, the top right has to remain in the diverging position since that is the only way to power the S section and without power there, one direction on the mainline could not receive power. You could switch the direction at the controller, but that will change the layout from from left hand running to right hand running, but the oval loop is not designed to allow that, so if you do this, then the oval loop must remain unused. This allows any direction of running on the two ballon loops and the main and single direction running on the oval. Since i have a yard in the right ballon loop with manual switches branching off between the bottom left switch and the power connection, the top right switch and the yard switch has to be manually thrown to allow power into the yard. This means it's not possible to have yard runaways in case the automated control fails. The middle switch is remotely operated along with the throttle, so it's possible to switch between the two trains or select between two routes for a single train.

 

ps: This layout (with some extensions) is still under construction and it tries to be a continous running switching puzzle for japanese interurbans and traction equipment with mixed passenger and freight operations set in the late 20th century. Yard turnouts are manual, the two ballon loop turnouts are automated with track sensors and the middle turnout is handled by CTC. (i choose this setup after getting too many shorts on the ballon loops because i wasn't paying enough attention on which switch was set where) Left side is meant to be industrial with farmlands on the edges, the middle is downtown and the right is residential.

Edited February 7, 2015 by kvp