The new Hornby Digital system differs from conventional 12v DC controlled systems in that the track is fed with a constant 15v DC and individual loco's are controlled internally through an electronic chip (decoder) rather than by varying the current to the track.

The Hornby Select and Elite digital units, once connected to the track, pass not only a constant 15v DC along the rails but also information signals to all locomotives and accessories that are on or connected to the track. Each decoder responds individually to signals transmitted to it and so it is possible to operate several at the same time.