DCC Turning Y

[tjerrard]

I have three of the Digitrax AR1s on my empire - three seperate reverse sections, one a wye. They went in easily and worked with no adjustment right out of the 'box'.

Tom 

[rolleiman]

The PM4 may be overkill for you if you only have the one Y. What it is, is a power manager of sorts that has 4 outputs. They can be set to simply power 4 districts (OR) you can power the main buss with one output and set the other 3 to be reversing. The PM4 is now the PM42 in the latest incarnation.. Certainly worthwhile IMO, if you are planning any expansions (like a turntable) and are using Digitrax. Otherwise, You might be better off looking into one of Tony's Train Exchange reversing units. He also carries the PM42 as well (made by Digitrax).

 

Edit: I was just browsing the digitrax site for something else and ran across this..

http://digitrax.com/prd_powerman_ar1.php 

Looks perfect for your one leg reversal needs and fits nicely into my block diagram.  I don't have any personal experience with it but it may be just what you need.

[Lateral-G]

Thanks rollieman.

I only have one turning wye. Now I have to find the Digitrax PM4 you mentioned.

 

and yes, my frogs are power routing....

 

-G- 

 

[rolleiman]

If the tail of the wye is a stub track and isn't connected to any other main line or track that leads to a main line, you can control it with DPDT contacts attached to the throw for the switch to the wye tail.  No reverser module required.  When you line the switch, you line the polarity automatically.  Simple and foolproof.

Dave H.

 

Unfortunately mine isn't (and can't) be like that. It's part of the main line.

 

-G- (nothing is ever simple or foolproof)  

.... but it can be..

Here you go..

The reversing unit can be anything, including a dpdt switch. An automatic unit works better however because it works in both directions and you don't need to remember to throw the switch. The auto units are current sensing devices that when they see a spike (short circuit) they will reverse the direction of the output. What you Don't want with one of these is two trains crossing the gaps at the same time.

In the drawing, whatever the bottom leg of the WYE is will be powered through the reverser, not the main DCC power buss. The gaps can be cut as close as the turnout frog, just make sure the wheels cross both rail gaps at the same time (don't stagger the gaps). 

I use a PM4 from Digitrax to control my 3 reversing districts. Haven't had a problem in 10 years of operating. The one unit I would NOT recommend is the MRC reverser. I would have never thought they could screw up a simple relay reversing circuit but they did. Waste of (at the time) $30. I don't think it has enough current capacity for more than a few locos (remember the power district is running through it rather than the main buss) and it gets confused. It may work fine for one single train on the layout. Or, it (the MRC unit) could just be plain junk.

Now, you Can, In theory, have the same reverser unit controlling More than one reversing district. Just as long you never have more than one train trying to activate it at a time. Remember that one of the beauties of DCC is this. The Locomotive does not Care what the track polarity is. The reversing of power to the motor is done in the Decoder, Not the track.

By the way, The above drawing assumes you have a power routed frog on the turnout.  

[Lateral-G]

If the tail of the wye is a stub track and isn't connected to any other main line or track that leads to a main line, you can control it with DPDT contacts attached to the throw for the switch to the wye tail.  No reverser module required.  When you line the switch, you line the polarity automatically.  Simple and foolproof.

Dave H.

 

Unfortunately mine isn't (and can't) be like that. It's part of the main line.

 

-G- (nothing is ever simple or foolproof)  

[dehusman]

If the tail of the wye is a stub track and isn't connected to any other main line or track that leads to a main line, you can control it with DPDT contacts attached to the throw for the switch to the wye tail.  No reverser module required.  When you line the switch, you line the polarity automatically.  Simple and foolproof.

Dave H.

[Lateral-G]

bump....

[Lateral-G]

  I have a Y as part of my mainline.  I have isolated all legs of the Y (both rails) and have a DCC reversing unit wired between one leg of the main and the Y.  Works well, no problems.

Tilden

 

Could you provide a wiring schematic? I'm planning on having a wye as part of my mainline as well.

 

-G- 

[WP 3020]

If you use a switch machine that has auxillary contacts, such as a Tortoise or the Atlas undertable switch macine, then you don't have to use an auto reverser. You can use the auxillary contacts to set the polarity to match the leg that the turnout is set for.

There are DPDT micro switches out there that you can use. They can switch polarity quicker than most contacts on most switch machines and could be used linked to a hand thrown turnout. I wouldn't use a separate toggle switch thrown independently from the turnout throw. Try to keep your layout controls as idiot proof as possible. This could be used on a single turnout reversing loop also. You only need to use automatic polarity reversing units on places in a layout that have more than one point of entry/exit in a reversing loop.

[Tilden]

  I have a Y as part of my mainline.  I have isolated all legs of the Y (both rails) and have a DCC reversing unit wired between one leg of the main and the Y.  Works well, no problems.

Tilden

[Mark R.]

I did as per the above poster mentioned. I have a set of auxiliary contacts on the switch machine leading to the tail of the wye. These contacts are fed to the tail of the wye and automatically change the polarity of the tail track when-ever the turnout is thrown. Requires no more wiring than the auto-reverse unit and costs a lot less .... not to mention 100% reliable and no adjustments required.

Mark.

[jktrains]

Jerry - The turning wye will need some sort of polarity reversing mechanism.  As some will suggest, a DPDT toggle switch will work; it won't be automatic, but it will work.  One of the benefits of DCC is that reversing polarity on things like a wye or a reversing loop can be done automatically.  The PSX-AR at Tony's is a top of the line unit.  It is completely electronic - no mechanically relays and such - it has a very fast reaction time and additional features such as indicator lights, adjustable trip settings and even the ability to control stall motor type turnouts.  It is money well spent.  You've gone top notch with your PHP, don't skimp on the other components.  BTW, I have one of the LogicRail NCE fastclock modules and they are really nice too, if you're into operations like that.

[CSX Robert]

If you use a switch machine that has auxillary contacts, such as a Tortoise or the Atlas undertable switch macine, then you don't have to use an auto reverser. You can use the auxillary contacts to set the polarity to match the leg that the turnout is set for.

[GAPPLEG]

I happened across Tony's web site, a reversing unit he sells , is that the one you used?  PSX-AR ? I read the manual and now it makes sense. I guess I should have googled first, I wouldn't have had to make a dumb post . Thanks.

[baron9]

 I have a Y attatched to my yard area and I run NCE DCC system. In order to make this work you will need a auto reverse unit and follow the directions that come with it. You will also have to isolate the Y tracks using the plastic rail joiners and add power from your bus wires. The auto reverse unit can be adjusted for electrical current to the Y. Hope this helps.

[GAPPLEG]

Has anyone built a turning "Y" , I am thinking about one to turn  locos end for end in my yard area. How is it  built and wired ? I assume a reverse loop module would be used , I haven't even started installing my DCC unit yet so I'm really new to the DCC world. Thanks