Before there was command control (Märklin Digital, DCC, Selectrix and others), there was advanced model train control using track switches, signals & relays and other devices. It’s kind of the ethos that European modelers have; call it Gods vs. Heroes.
The Germans were quite good at this, and most model railroad manufacturers had a color-coded wiring system which made this process easier. Both the AC powered (mostly Märklin) and the DC (most of the rest of the European model train world) had color coded systems which were designed to help the model railroad layout builder create a system which simplified train control. Of course, command control has replaced the need for a lot of this, but there are still people out there who don’t want command control and the extra layer of learning that it requires. You know who you are, and I’m not going to judge you since there are some compelling reasons to keep it simple.
That said, you can make it more complicated with signals and such, but even if you don’t go that route, there is still the necessity of wiring up the track to run a train and wiring up the track switches so that you can operate them remotely. These pages are for you.
It doesn’t matter that the Minitrix electrical items were also the Trix electrical items, but it certainly made things simpler for Trix dealers. Trix had a color-code system that is logical and straightforward. Their transformers, which converted household electricity into model railroad electricity, had four connections:
Track power is variable Direct Current (“DC”) that ranges between 0 and around 12 volts.
- Blue - “Track Common”.
- Red - “Track Power”.
We use the term “Track Common” and “Track Power” because you will find these terms to be useful if you operate a locomotive from overhead catenary wires or if you use signals to control train movements. It doesn’t make sense to call them “+” and “-” because in any given situation that would depend upon which direction the train is operating. With DC train control, it is the track polarity that determines in which direction the locomotive motor is operating.
Accessory power is typically 14 - 16 volts Alternating Current (“AC”), but it can be higher if you are measuring the power output without any load.
- Black - Accessory “Ground”
- White - Accessory “Hot”
Even if you do not use a Trix manufactured transformer, the same rules apply.
Connecting to the layout
In the simplest layout installations, one connection from the red terminal of the power supply is made to one rail and a second connection is made from the blue terminal to the other rail. If you want building lights, the connections of the light bulbs are made to the black and white terminals.
The remotely operated devices such as turnouts and uncouplers have color coded wires. The turnouts have green, white and yellow wires which are connected to control buttons. The uncoupler, which has only one solenoid, has two wires, green and white.
If you follow the Trix color coding protocol, then everything is properly connected together and everything works. The Minitrix electrical components are fitted with spring clips, so you do not need to solder things together. Because of these spring clips, you do not need to plugs and sockets used by other systems.
From there, it gets more interesting. The various devices at your disposal are discussed here. Remotely operated track switch connections are discussed here. Train control with signals is discussed here.