Model Railroad
Electronics:
This information has been provided for your reference:
Light Emitting Diodes (LED's):
If you intend on using standard (non flashing) LED's for your
model railroad projects, the following data will help you select
the right LED for the DC supply voltage. (Vf=2V, LED current
20mA).
|
6 Volts |
R = 220 ohms |
|
9 Volts |
R = 330 ohms |
|
12 Volts |
R = 560 ohms |
|
24 Volts |
R = 1200 ohms |
Resistors should be soldered to the anode (A) side of the LED or
you could damage the diode.
Resistor Values:
Model Railroad Layout Wire Sizes:
There are two types of wire that can be used for wiring a model
railroad layout:
Solid
Wire:
Solid
wire is easy to connecting to screw terminals as well as the
fact that there aren't any strands that can "wander over" to any
nearby terminal connections and cause a short circuit. Solid
core wire is not easy to find in Australia.
Stranded
Wire:
The
stranded type is flexible, less likely to break or crack with
repeated bending, and of course, can be picked up from your
local electronics store at a realistic price.
Selecting the right gauge is important. If the wire gauge you're
using is too small for the application, there will be too much
resistance in the wire and this will either cause the device not
to work properly or, worse, the wire may heat up too much and
become a fire risk.
As a rule of thumb, the following is a list of recommended wire
gauges to use for model railroad wiring:
• 24-gauge wire for lighting;
• 22-gauge wire for remote turnouts;
• 18-20-gauge for track feeders; and
• 14-16 for track power bus.
There may be variations to the above for DC and DCC wiring and
the information is provided as a guide only.
Wiring Tools:
To ensure that you have the correct tools to wire, solder and
test the wiring on your layout, you should have some basic tools
available, these include:
·
Wire cutters;
·
Wire strippers;
·
Crimping tool (if using crimps);
·
Multi meter;
·
Soldering iron;
·
Soldering iron stand;
·
solder:
Bus wiring:
In regular block wiring for cab control, you can use a bus for
the common (negative) wire. In this case, you run the bus wire
all around the bottom of your layout usually under the layout
base. Then run track feeder wires from the common rail of the
track to the bus. Usually it’s best to have a track feeder for
about every 3 feet of track to assure that adequate current gets
to all areas of the track throughout the layout.
You can connect each track feeder to the bus using a terminal
strip, or you can strip the insulation off a small section of
the bus wire, then wrap and solder the feeder wire to the bus
wire.
For DCC wiring, you can have bus wires for both the positive and
negative wires going all around the layout. Then connect feeder
wires from the track rails to the appropriate bus, joining
positive rails to the positive bus and negative rails to the
negative bus.
This
makes model railroad wiring for DCC much easier, because you
don’t have to have multiple blocks with separate feeder wires
going from the positive rails to switches on your control panel.
The only problem with using buses for DCC is that if you get a
short circuit somewhere, the whole layout shuts down. This is
why many people recommend that if you have a large layout, you
should separate your track layout into electrical blocks that
are connected to circuit breakers then on to the booster unit.
That way, if you have a short circuit, in one block, it will
trip the circuit breaker for that block only and the rest of the
layout will still be functional. You can then narrow your
troubleshooting to that section of the layout connected to that
circuit breaker.
How do you attach feeder wires to the tracks?
Specially-made wired metal rail joiners can be purchased and
used as track feeder wires for your model railroad wiring.
However, you can easily do this yourself by soldering one bare
end of the 18-20 gauge feeder wire to the outer side of the
track rail after I have threaded the wire through the layout.
The other end of the feeder wire can be attached to the bus
cable via your preferred method underneath the layout, or
spliced to an extender wire to carry it back to a switch on the
control panel.
How do you splice the ends of 2 wires together?
One method is to place a section of heat shrink tubing over one
end of one of the wires, then wrap the bare ends of the wires
tightly around each other, then solder them. Then move the heat
shrink tubing over the connection while the solder is still
fairly hot. You can also use the side of the soldering iron
along the heat shrink tubing to heat it if necessary. Another
method is to put a straight splice connector over one of the
wires, wrap the bare ends of the wires together tightly, then
slide the splice connector over the connection and crimp it
using a crimping tool.
Threading wires through the layout surface:
How do you thread small gauge wires through several layers of
extruded foam and plywood to get from the surface to the
underside of your layout?
If you’ve ever tried to do this, you know how difficult it is.
The best method for doing this is to get a long drill bit at
least 3-4 diameters larger than the wire. Drill the hole through
to the bottom of the layout. Then insert a metal tube, which you
can buy at hobby stores, through the opening to the bottom. Then
thread the wire through the tube. If necessary, you can attach a
small fishing weight to the wire to help pull it down through
the tube. Once the wire is through the tube to the other side,
you can slide the tube out, leaving the wire in place.
Terminal Strips for Model Railroad Wiring:
Terminal strips are just strips of plastic with screws lined up
on either side where you can fasten wires. These strips are
made of plastic for isolation of the circuit and can be cut to
suit the application. If you only have a positive and earth,
you can cut the strip to have only two strips, rather than the
twelve in the photograph.
Cable Splice Connectors:
Quite simply, to connect wires such as droppers to the main
power bus, you insert the wires to be connected, close the
"pillow" and close shut with a set of pliers. This is a
sturdy connection that can be made anywhere on your layout with
minimum fuss.
Push In Type Connectors:
Push-in type wire connectors are designed so that you can just
insert the wire into a hole, then drive a flat-ended screw on
top of the wire to hold it in place.
Tag Strips:
Tag strips can be purchase in various sizes (2, 3, 4 and 8) tag
sizes. Tag strips are useful for connecting droppers to the bus
(at any location) as you can strip the bus and solder to the
dropper. It is useful to cut through the top of the tag so that
the stripped wire can be put into the tag ready for soldering.
Crimp Connectors:
Crimp connectors can be crimped onto the bare ends of wires to
use as a neater way of attaching wires to screw terminals. These
can be rounded or U-shaped, depending on how secure and/or
permanent you want the connection to be. The U-shaped ones are
easier to connect and disconnect without having to take the
whole screw out each time.
As a rule of thumb, the following sized crimps are available
indicated by the colour of crimp:
|
Crimp Colour |
Cable Entry Size |
Wire Size |
|
Red |
4.3mm |
0.75 - 1.0mm wire |
|
Blue |
4.3mm |
1.5 - 2.5mm wire |
|
Yellow |
6.6mm |
4.0 - 6.0mm wire |
Note: This data is provided as a guide only and should be checked
against manufacturers data.