DB150 booster installed for upper level circuit piggybacked from the toy train xfmr supply for the command station. Note: despite care used in matching rail polarities, the rail A/B outputs of the DB150 are reversed from the command station and Zephyr. To correct this, the feed from the booster is reversed feeding the railroad. Train successfully operated over boundary. This unit can function as a limited-function command station in an emergency. Either one can carry the load of the entire railroad.