Where is my train?
Basics of block detection
O
ne of the main benefits of DCC is that you have constant
power on the track. This allows things like cars having
constant brightness lights – perhaps we’ll delve into tech-
niques for this in a later column. The topic on the table just now is
how to know if there is a train on a specific section of track?
The constant power allows a simple device, known as a block
detector, to see if any power is being consumed in a specific sec-
tion of track. DCC decoders always draw some power, even if
the loco is not moving and no lights are on. So, locos are easy to
detect, as are lighted cars. Unlighted cars, like freight cars, are
more difficult, but possible.
First, why do folks care about knowing that a track is occupied?
There are many reasons, running the gamut from following the
progress of a train through hidden staging to signaling the layout
to full computer control of a layout.
Okay, you isolate the section (cut gaps or use insulated rail joiners)
that you want to detect from the rest of the layout, add a block
detector and you are done. Yes? Not quite. Let’s try to take some
of the mystery out of the process.
DCC Impulses column
by Bruce Petrarca
What you need to locate your train on the layout ...
DCC Impulses - 1
MRH-Aug 2013
