# Product available to auto-throw a loop track turnout/switch?



## Busrider (6 mo ago)

Hello All,

Is there a product available that can be tied to a Loop-reverser (reverse loop module), that in turn will automatically change the direction of a switch/turnout?

I presently have the following on order ...
*Ring Engineering AR-1 RailPro Auto Reversing Module*

Unfortunately I did not see anything within it's manual that indicates that it has an aux out or accy signal feature, that would accomplish what I need (auto switch throw).

The layout is N gauge, analog DC, not DCC.

Thank you


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## Lemonhawk (Sep 24, 2013)

I don't think that unit works on DC, only DCC. I believe that a DC only layout will not harm the device, just that it will not work. It also mentions it only work with the Rail Pro System.


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## CTValleyRR (Jul 26, 2014)

Lemonhawk is right. An autoreversing unit works by matching the polarity of the reversing section to that being exited by the train. Since the decoder is rectifying the current and assigning the correct polarity for the direction of travel before it sends current to the motor, the autoreverser prevents a short without affecting the operation of the train.

In DC operation, the polarity of the current determines the direction of travel, so if the autoreverser tripped, it would reverse the direction of the train (without stopping it first, and that's hard on the drive train.

In DC, what you are trying to do will be a lot more difficult. You're probably looking at a fairly complex, Arduino-based solution.


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## wvgca (Jan 21, 2013)

an autoreveser can be built with a ltaching relay and a resistor for dc, i made one to burn in dc locos. drawback is that it reverses direction without gradually reducing power first ..


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## Lemonhawk (Sep 24, 2013)

There appears to be confusion over what an auto reverser is. It does not reverse anything visible. With DCC it corrects the pulse phase to eliminate a short as metal wheels cross an insulated barrier. The "auto reverser" detects the short before the controller, and swaps the phase so there is no longer a phase difference across the insulated barrier. At no time does any locomotive reverse direction.


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## SF Gal (11 mo ago)

I don't even want to do down that DC switch rabbit hole without "manually" switching the block you turning back into.
You could have a infared detection sensor sensing the caboose passing and turning on a relay to change the direction of the turnout on both sides of the turnout. But switching automatic DC polarity would mean relays switching at every block all down the line before the train arrives at each block. I suppose if it was only one block between the reverse loop tracks, relays and sensors might be the option you desire.


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## Busrider (6 mo ago)

Thank you for the replies and insight.
The loop and turnout in question are primarily concealed, thus the desire for an automatic turnout.

This is what Ring Engineering says about their AR-1 Reverse Module :
*Description*

*This product is specifically designed to be used with DC and/or RailPro products. It cannot be used with DCC products.*

Evidently there is more than one Auto reverser available for DC operation and both use the designation AR-1. Circutron model 800-5400 is one other example.

Regardless, I see everyone's point and the complexity required to accomplish the goal has me thinking of doing away with the loop idea.


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## DonR (Oct 18, 2012)

I agree with SF Gal

Some sort of occupancy sensing devise tripping a
relay could be used to
throw the turnout when the LOCO reaches
a certain point in the loop and BEFORE it gets
to the turnout. You would need such a devise
at both ends of the loop since the train could enter
the loop going in both directions. You would need
a capacitance discharge unit if turnout has twin coil
motor but it may be easier to use a Tortoise stall
motor. You would also need a manual turnout
control so operator can select which route the
train can take.

Don


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## Dennis461 (Jan 5, 2018)

Don't give up.
If you have a large loop, put the rail gaps further away from the turnout, further into the loop.
Now, when loco is far away from turnout. Polarity will change (giving time to switch turnout).
Make sure the AR has a relay.
Cut into relay and solder on wires.
Now build a circuit to sense AR status and throw turnout.😀


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## Busrider (6 mo ago)

... I thought about a relay and the loop has adequate length - let me give it some thought.

Thank you for reaching out.


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## CTValleyRR (Jul 26, 2014)

Busrider said:


> Thank you for the replies and insight.
> The loop and turnout in question are primarily concealed, thus the desire for an automatic turnout.
> 
> This is what Ring Engineering says about their AR-1 Reverse Module :
> ...


Railpro isn't traditional DC, it's DC power to the rules but RF control of locomotives. 

Things that are designed to work with their systems generally don't play nice with other setups.


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