Patent ID: 7279871

Claim:
A voltage regulator for an alternating current source used for powering operating features of a model train, comprising: a load control unit having an output configured to be coupled to a model train operating feature, said load control unit being responsive to a load control signal for controlling the delivery of current to the operating feature during at least a portion of an alternating current waveform; a feedback unit coupled to said output of said load control unit and configured to produce a feedback signal indicative of a voltage level of said alternating current source applied at said output; a controller adapted to receive an input command pertaining to the operating feature, the controller being responsive to said feedback signal and configured to generate said load control signal such that said voltage level substantially corresponds to a predetermined reference voltage level; and a zero-cross detection unit operatively connected between said system power source and said controller, wherein said zero-cross detection unit is configured to detect a zero crossing of said alternating current waveform; wherein said controller is configured to use said detected zero-crossing to control activation timing of said load control signal and to synchronize said load control signal with the input command.