What Do Timed Voltage Pulses Have To Do With DCC Model Train Operation?

April 11, 2023

Tony sent in this short article to share:

Thanks to the invention of the transistor in 1947 and largely because of the US space program and the cold war, we live in an entirely different control world today. Analog control systems are mostly museum curiosities, and the world has gone almost completely digital. We now control complicated spacecraft with the tiniest of signals over billions of miles of space. And believe it or not, the basic element of the control system is so simple that it’s almost unbelievable. A simple on-off signal does all the work! That’s right! After a hundred years of increasing complexity, we have left all of that behind and are working at the level of the most basic control systems ever invented.

OK, caught in the act! Digital control isn’t really THAT simple, but the on-off nature of the signals it uses certainly is. What is different about today’s control from the analog world, is that instead of looking at what value of the signal, they now detect the duration or timing of the signal. One of the greatest features of solid state (transistorized) electronics has been the ability to generate exceptionally accurate timing, which all digital control systems use extensively. In fact, the entire underpinning of Digital Command and Control is the generation of precisely timed voltage pulses. Digital electronics also makes it easy to count pulses and store them and execute actions based on the counts. This is precisely what DCC does.

At this point, we could degenerate into a detailed, multi-volume dissertation of computer system organization and theory to explain how this all works, but unless you actually are interested in the gory details of that side of control systems it would be much better to just make a statement about the end effects of a command rather than the theory of computer processing and microcontrollers.