# Use of Digitrax AR1



## Sunsanvil (Jan 25, 2017)

Looking into implementing a reversing loop, we already have a Digitrax Zephyr. I looked up their AR1 but the instructions are quite sparse: they only show wire connections to the loop and main sections.

How does it actually work? By the sounds of it the train does in fact create a short as it enters/exits the the loop, and on sensing that short the AR1 flips polarity? Why does that sounds like a bad idea?


----------



## Lemonhawk (Sep 24, 2013)

You have described exactly what it does. It's not bad because it does it so fast! Besides the AR1 if you want train detection, look at the BXPA1 and BXP88. They act as circuit breakers and train detectors, with the BXPA1 providing the reversing function.


----------



## Lemonhawk (Sep 24, 2013)

You have described exactly what the AR1 does! It's not bad, because it does it so fast. If you also want train detection, instead of the AR1, use the BPXA1 (for the reversing parts) and the BXP88 for the normal part of you layout. These units also provide circuit breaker protection (replaces the PM42). There is also something called a frog juicer that just connects to the turnout frog (and the rails) and will automatically switch the rail phase correctly as the train goes across the frog -- keeping your frogs powered. Frog juicers are not compatible with the BPX devices.


----------



## DonR (Oct 18, 2012)

You can be assured that you will be pleased with
the AR1 to match phase for your reverse loop.
It does seem 'archaic', in this digital age, to depend
on a 'short circuit' as a sensor to do a switching chore but it
works fine. And surprisingly, your locos, even at a slow
speed, will run smoothly over the insulated joiners with
nary a flicker of the headlight.

The AR1 has a sensitivity selector that can be reset if
the span short triggers the DCC controller (some are more
sensitive to shorts than others) If necessary, you
can use that will restore proper operation. Once
set you never have to do anything with it.

Don

Don


----------

