Railroading Basics Title
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Wiring your model railroad can be difficult. In fact it is
area which gives most newcomers to the hobby the most problems.
reason is that most of us are less familiar with the details of
electrical and electronics than mechanical components. But if you start
with a relatively simple layout it shouldn't be too difficult.
Fortunately there are numerous reference books that can help.
The first component needed is a power supply commonly called a power
pack for DC powered layouts and a transformer for AC power. There
are lots of options and we don't discuss them further here. See Wiring Basics
the NMRA Beginners website.
You've probably noticed that most model railroad layouts have track
with two rails just like real railroads. Two rail layouts are
always powered by direct current (DC). DC is simpler to
one rail is positive and the other is negative.
But notice what happens in a reversing loop where a train changes
direction: to keep a train going forward the positve rail must become
the negative rail and vice-versa so the polarity must be switched with
an electrical switch. Electronics can offer an automatic
solution. Polarity problems also exist where the rails in a track
switch cross each other (called the "frog"). The simplest
solution is to insulate the whole frog (some switches provide this) but
all locomotives must have amply spaced electrical pickups (the wheels)
in order to
bridge the insulated gap or the train will stop.
3 rail AC powered layouts avoid the polarity problems because both
outside rails can be connected together. But the third middle
rail must have gaps at track switches so once again there is an issue
with electrical pickup spacing. Most 3 rail equipment that needs
electrical power has a sliding or rolling contact on the middle of the
underside and can be spaced at opposite ends of the loco or car and is
usually sufficient to bridge any third rail gaps.
In the past few years electronics have become more common in model
railroading. Perhaps the greatest advance is Digital Command
Control (DCC). DCC replaces control of model trains by adjusting
the voltage by sending digital commands from a hand held or wireless
control module to the model railroad via the track or through the
air. Note that a wireless controller likely will still operate
the trains via commands sent through the track. A good reference
is the NMRA DCC Home Page
Another electronics advance is sound systems. Today your model
railroad locomotive can sound like the real thing due to sophisticated
electronics. Sound systems are usually associated with DCC
(although not strictly necessary) so much of the information about
sound systems can be found at DCC referencces.
Additional electrical issues not covered here include on board
components, signaling, passenger car interior lighting and electrical
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