The Digital Model Train Part 1

42 EE 9 THE DIGITAL MODEL TRAIN PART 1 by T. Wigmore As every railway modeller knows, the control of model railways is being transferred inexorably from the heavy-duty switches and relays of yesteryear to the digital computer. In a new series of articles, we describe a number of units based on the new technology, culminating in a fully electronic model railway. The series commences with a description of the Marklin control system in which all commands to the signals, locomotive and points (turnouts) are given via the rails. Although in this and some future ar- ticles reference will be made to the Marklin system, it should be noted that a number of units will be described that may not only replace the relevant Marklin circuit, but can be used in a var- iety of DC railways of other manufac- tures. Rails: a serial bus In any model railway, there are a number of operations that must be under full control at all times. Points (turnouts) and signals may be operated in- dependently of on...