volt

Definition: Volt is defined as the unit of measure for electrical potential. Most model trains use voltages levels from zero volts (to stop the train) up to a maximum voltage for the train's fastest speed. The maximum voltage differs from scale to scale, larger scales having higher maximum voltages. Two-rail systems use direct current (DC) power, while three-rail systems use alternating current (AC). However, DCC equipped trains are a bit more complicated.