2-Rail TMCC Accessories

Automatic Reversing Booster

The Automatic Reversing Booster, or ARB for short, is designed handle your reverse loops and crossovers when using 2-Rail TMCC. (Rated for 20 Amps @19 VAC)

The ARB has a total of 4 wires; two wires connect to your mainline rails and two wires connect to the reverse loop rails. The reverse loop is gapped on each side of the switch (the diagram below illustrates this configuration).

When the train travels over the gapped section of rail and the polarity is mismatched, the ARB detects the short and immediately reverses the polarity of the power. This happens so fast that the train nor the power pack detects the short. The train continues into the reverse loop as though nothing happened. When the train reaches the other side of the switch and the polarity is once again mismatched, the ARB reverses the polarity again and the train travels out of the reverse loop as smoothly as it did when it entered. The ARB works the same way for crossovers as well.

One ARB is required for each reverse loop or crossover.

Signal Enhancer

The Signal Enhancer is the device that makes TMCC work in a 2-rail environment. The Signal Enhancer allows the Command Base signal to be transmitted through both rails without creating a short circuit. One Signal Enhancer is required for each block, if the power is broken into blocks. Or, one Signal Enhancer is required for each transformer.

TMCC (Scale Command), originally developed for 3-rail trains, broadcasts the Command Base radio signal over both outside rails, creating a halo around the track. This halo cannot be recreated without a Signal Enhancer on a 2-rail track. By coupling the Signal Enhancer to the track and the Command Base you can transmit the radio signal through both rails (without a short circuit) to reproduce the halo required for TMCC to work reliably in a 2-rail environment. The diagram below illustrates how the Signal Enhancer wires to your layout.