Auto Reversers

[Philip H]

So, following on the innovation of @davefoxx and the rolling reverse loop he has added to his SBD layout, me thinks a temporary loop arrangement might do the ticket for me in my temporary housing situation.  That said I know NOT a THING about auto reversing circuits.  I know Digitraxx and MRC have them on the web, as do TCS Tam Valley and a whole host of other folks. Given that I have a NCE Powercab dcc system - does any one care to point me to the most economical AR solution that I can wire up for this use?

THanks!

[John]

It gets no simpler and cheaper than this.. works in DCC as well



Barring that, I have an AR1 you can get for cheap

[davefoxx]

@Philip H,

As noted, I have the Digitrax AR1.  I went this route, because it was much less expensive, and, at the time I bought it, I was using it for a simple loop on the Southern Ry. interchange that saw very little traffic.  My AR1 has worked flawlessly since I first installed it a few years ago on the SOU interchange and now in its reincarnation on the new return loop.  However, the AR1 is a mechanical relay, so some folks have reported issues.  Confer with others here, but I think that the PSX-AR, which is solid state (not mechanical), is the more reliable way to go.  It's much more expensive, though.

Hope this helps,
DFF

[MVW]

Here's a nice rundown of options:
https://tonystrains.com/dcc-auto-reversers/

We used a couple PSReverser units on a previous layout. I didn't install them myself, but I remember it was pretty quick and easy.

I'll have a need for something for staging later this year, so I'm also interested if anyone has a better option.

Jim

[peteski]

The NCE PowerCab can only supply about 1 or 1.5A of current.  As long as the breaker/reverser trip current can be set to less than 1A of current, it should work. But if the trip current is higher than what the PowerCab can deliver then it will shut down the entire system before the reverser trips.

[seusscaboose]

@Philip,

As noted, I have the Digitrax AR1.  I went this route, because it was much less expensive, and, at the time I bought it, I was using it for a simple loop on the Southern Ry. interchange that saw very little traffic.  My AR1 has worked flawlessly since I first installed it a few years ago on the SOU interchange and now in its reincarnation on the new return loop.  However, the AR1 is a mechanical relay, so some folks have reported issues.  Confer with others here, but I think that the PSX-AR, which is solid state (not mechanical), is the more reliable way to go.  It's much more expensive, though.

Hope this helps,
DFF

point to Mr. Foxx.

[davefoxx]

The NCE PowerCab can only supply about 1 or 1.5A of current.  As long as the breaker/reverser trip current can be set to less than 1A of current, it should work. But if the trip current is higher than what the PowerCab can deliver then it will shut down the entire system before the reverser trips.

@Philip H,

You might want to do further research for verification, but my brief internet search shows that the AR1 and the PSX-AR are adjustable down to a level that should work with the NCE PowerCab.  Kudos to @peteski for thinking of this issue.

DFF

[jagged ben]

It gets no simpler and cheaper than this.. works in DCC as well



Barring that, I have an AR1 you can get for cheap

That's not gonna work too good if you want to run through the loop without stopping.

[eja]

Just curious ... Why ?

[John]

That's not gonna work too good if you want to run through the loop without stopping.

Just curious ... Why ?

With the toggle switch, you have to throw the switch while the loco is in the loop before it gets to the gaps .. I've thrown them while the train is running, and the decoder keeps the loco going ... if you are paying attention, it shouldn't be a problem ..

All the other reversers, the AR1, PSX etc .. they all operate on the same principle .. reverse the polarity at some point while the engine is in the loop ..   just depends on how automatic you want it to be, and how much money you want to spend

[eric220]

That's not gonna work too good if you want to run through the loop without stopping.

It will if it's DCC! 

I'm one of those that had problems with the AR1. I had one short out internally and take down the whole layout. I had another that I could not for the life of me get to trip reliably. Either it double-tripped and caused the loco to short (indicating it was too sensitive) or it would not trip at all (indicating it was not sensitive enough). Sometimes it would do one on one loop and the other on the next, with no adjustments. After the whole-layout-down fiasco, I replaced all of my AR1's with DCC Specialties (the same guys that make the PSX) OnGuard auto reversers. They've worked beautifully, and silently. Unfortunately, they have a fixed trip amperage that is too high for your system. The PSX is adjustable down go 1.27 amps.

[jagged ben]

It will if it's DCC! 

I didn't realize the MRC Tech III was a DCC system.   

_{I would add: if I wanted to throw lots of switches to run trains, I  wouldn't go DCC in the first place.}

[Philip H]

An educational Railwire discussion - who'd a thunk? Looks like I have an option in the works for the automated approach. Now to build a Foxxy Loop!

[peteski]

If the switch a the entrance to the reverse loop is activated through a switch machine which has auxiliary contacts you can automate the DPDT switch circuit.

First, gap the rails close to the turnout.  Then replace the manual DPDT switch with a DPDT relay. Power the relay's coil through the switch machine contacts in such a way that the polarity of the reverse loop will match the route selected by the turnout.  That way the loop will always match the polarity of the selected route.  I hope that this makes sense.

This gives you automated reverse loop without using a DCC reverse.

[djconway]

The toggle switch will have a momentary no current point as it breaks one connection and makes the other.  Tou don't see the interruption on relays because the break / make connection happens so fast.  A fully electric switch is even faster than the relay or toggle.

Set an operational rule that the train has to stop to throw the switch (and toggle) and it will work.