Three-Rail Innovations' Automatic Train XChange controller gives the toy train operator a single controller that can be used to run two trains on a single track loop or dispatch a single train from a passing siding "yard."

The same controller can also provide automatic route selection for track switches.

There are three inputs that are connected to isolated-rail track blocks, electrical switches, or relay contacts. There are two single-position-double-throw (SPDT) relays. Jumpers are placed across two columns of seven pins to select the operating features to be activated.

The Automatic Train XChange Controller is an electronic circuit board, approximately 3.0 inches by 2.8 inches. Electronic components provide complete isolation among inputs, outputs, controller power, and the controller's circuitry. A small microprocessor is used for all logic, control, and timing functions.

The ATX circuit board is arranged with a wire connector for isolated outside-rail inputs on the bottom-left and wire connectors for board power and relay outputs on the right. There is also a block of jumper pins in the upper-left.

The controller uses LEDs to show activity. A status LED shows power is applied and the state of trains in "stop" track blocks. Two LEDs glow to show that a relay is activated.

Jumpers are placed for feature selection.

LEDs indicate power ON, train "stop" block state, and relay activation.

Wire connections are made for inputs, board power, and relays.

The ATX uses isolated outside-rail track sections to sense a train or operator switch and SPDT (single-position-double-throw) relays for train power, or to activate track switches.

Wires from insulated rail track sections or electrical switches go to the outside-rail inputs connector. Inputs are powered from a fixed-voltage, AC transformer between eight and twenty volts. Connections consume very little power: fifty active input connections can be driven with a one-ampere transformer.

Each of the two sets of relay normally-open and normally-closed contacts can switch up to eight amperes of AC or DC power at up to 30 volts.

The ATX circuit board is powered by an AC transformer between twelve and fourteen volts. The controller uses little power; ten controllers can be powered from one ampere of power.

Three-Rail Innovations' Automatic Train XChange Controller is expressly designed for the toy train operator and to be used on a toy train layout.

The following table provides operating specifications for the ATX.