This section deals with the various aspects of using electricity in models and layouts.
Introduction
Most model railways use electricity as the means of propulsion. Whilst some (mainly older) layouts use 3 rail or Stud Contact, the majority use 2 rail. Until about 1999 the almost universal system was to use DC (Direct Current), with the speed of the loco controlled by varying the voltage, usually up to 12 volts. This is well understood and will not be explained here - the system is now sometimes known as “Analogue” or just “DC”.
It is increasingly common today for a layout to use DCC (Digital Command Control) which uses an alternating voltage with command signals overlaid to instruct each loco separately to move when required.