Out and back and reversing loop wiring

[mikesndbs]

Hi

 

Can anyone advise on the best way to achieve this please?

Obviously the polarity needs to change but how to do this seamlessly as the train runs?

[kevinlms]

3 hours ago, mikesndbs said:

Hi

 

Can anyone advise on the best way to achieve this please?

Obviously the polarity needs to change but how to do this seamlessly as the train runs?

Several different ways. Near the foot of the page.

 

https://www.brian-lambert.co.uk/Electrical_Page_3.html

 

You will note, that it's not exactly easy and something that is a breeze in DCC!

[BR60103]

The requirement is two reversing switches which are not in the throttle/power pack. One controls direction in the base part of the layout; the other controls the loop. 

#1 is set to take the train out of the station; #2 is set to take the train around the loop CW (say). while the train is in the loop, the direction switch for the station is changed and the point is changed to receive the train from the loop. 

If you want to run the other way around the loop, #1 is for out and #2 is CCW.  Change point and #1 switch as before.

 

If there are more throttles, each would require two direction switches.

You might get away with shunting in the station using the throttle direction switch, but leave it in the standard position when done.

[AndyID]

On 12/09/2020 at 01:36, mikesndbs said:

Hi

 

Can anyone advise on the best way to achieve this please?

Obviously the polarity needs to change but how to do this seamlessly as the train runs?

 

How "seamless" do you want it to be?

 

It's not terribly difficult to make it entirely automatic so that you don't have to do anything but run the train into the loop but to do that you will need to make the controller reverse automatically. That's not very difficult but you'll need to mess about with relays and some LEDs.

 

We can show you how to do that if you feel up to it.

[Suzie]

It is actually quite easy in DC. Just use the 'Bridge Rectifier' method from near the bottom of Brian Lambert's page. It is very simple, just isolate the reverse loop, and feed it via a bridge rectifier.

 

The only limitation is that you can only go round the loop one way, but that is a small price to pay for very simple wiring.

[Michael Edge]

I've done this with a triangle on a continuous run layout - one leg of the triangle has the power fed through diodes, while the train is on this section you simply reverse the controller's direction switch. The train continues to move in the same direction since the diodes don't allow the current to be reversed but the controller is now set the right way when it moves off the triangle. I've got a diagram for this somewhere but I can't find it at the moment.

[Suzie]

The diagram is in the linked page above. Brian has a lot of diagrams and is very thorough.

 

Reverse loop wiring with bridge rectifier

https://www.brian-lambert.co.uk/Electrical_Page_3.html

 

If using a Peco Electrofrog or Unifrog you don't need the breaks in the frog rails, you can just cut the links under the point before laying it instead.

 

Just swap the '+' and '-' connections on the bridge rectifier if you want to go the other way round the loop.

 

One component (the bridge rectifier) and four wires. It really could not be any simpler.

 

Edited September 16, 2020 by Suzie

[Michael Edge]

That's it, it's really easy to do and works very well. In my triangle installation there is two way changeover switch in the relevant track on the panel to allow movements in both directions.

This is the track diagram, the reversing section is shown in red between the signals.

This is what the control panel looks like, switches mounted sideways connect the separate sections to controllers at each side of the panel, the changeover dorection switch is mounted in line with the track. Black sections are switched automatically by the point settings.

[kevinlms]

6 hours ago, Suzie said:

The diagram is in the linked page above. Brian has a lot of diagrams and is very thorough.

 

Reverse loop wiring with bridge rectifier

https://www.brian-lambert.co.uk/Electrical_Page_3.html

 

If using a Peco Electrofrog or Unifrog you don't need the breaks in the frog rails, you can just cut the links under the point before laying it instead.

 

Just swap the '+' and '-' connections on the bridge rectifier if you want to go the other way round the loop.

 

One component (the bridge rectifier) and four wires. It really could not be any simpler.

 

Swapping the two blue connections is easy too, just wire them up via a Peco DPDT switch or relay that operates when the point is thrown.

[mikesndbs]

Thanks all, work and home commitments have stopped play just now, but I am following and will take good note soon