Model train locomotive with doppler shifting of sound effects

摘要

Electronic circuits and methods are disclosed for remote control of a locomotive in a model railroad layout having an interruptible DC power supply coupled to the railroad track. The locomotive motor is isolated from the track so as to allow use of polarity reversals on the track power signal for controlling remote effects in the locomotive such as sound and visual effects. An on-board electronic state generator is provided in the locomotive for maintaining one at a time of a predetermined set of states, at least one of the states having a corresponding remote effect associated therewith. Remote control signals such as a pulsed reversal in polarity of the DC track power signal (PRP) or high voltage pulse (HVP) are used to clock the state generator to a desired state, thereby permitting control of a plurality of remote effects using only the traditional DC power supply interface. Further remote effects can be controlled by using the amount of DC voltage superimposed over the AC track signed to indicate, for instance, a desired pitch for the train horn. Alternately, the length in time at which a remote signal is applied to the track can itself serve as coded instructions to an on-board remote control selection memory.