Abstract: A model train accessory controller is connectable to a DC power pack having a throttle to apply a power signal to a set of train tracks. The controller includes a switching device, which is in electrical communication with the power pack and the train tracks, to reverse a polarity of the power signal on the train tracks. The controller includes an input, and a processor in electrical communication with the switching device. The processor receives a command from the input to produce, by control of the switching device, a digital command having a series of sequential reversals in the polarity of the power signal.

Abstract: A model railroad remote object comprises a proximity detector, an on-board accessory, and an on-board processor. The proximity detector changes state based on proximity of the detector to a proximity source. The accessory, which is located on or within the remote object, exhibits a behavior based on a parameter. The processor, which is operatively connected to the proximity detector and the accessory, affects the value of the parameter of the accessory based on the state of the proximity detector. By way of illustration and not limitation, the on-board accessory may be an audio device, the behavior may be emission of sound, and the parameter may be sound volume.

Abstract: On-board model railroad speaker enclosure designs are presented that allow maximum sized speakers, improve impedance matching of sound to the outside of the locomotive, and isolate back and front speaker waves while maintaining the standard horizontal drive-train in model train locomotives.