Electrical control

In this post, I'll deal with how I plan to control the trains and the lighting on the layout itself.

I'm putting a lot of thinking into the electronics for the layout.  In the past, I've been very casual about wiring.  I've run bus wires underneath the last 4 layouts for train power and accessories but have pretty much left lighting to chance or used the same circuit as for the accessories.  This time, I'm going to plan better and have wiring that is properly designed and documented and is something I'll be proud to show people.

I have both Lionel and MTH locomotives and I want to continue being able to make that choice.  A basic CAB1 will control the Lionel locos; an MTH Explorer will control three of the MTH locos - this is a small layout after all. In later phases, I may add one or more ASCs for TMCC to control track switches.  If I find the MTH explorer too limiting, I can always upgrade to a full-function TIU.  It will be possible to have three operators working simultaneously:

• One running a thru train on the main
• One switching in Tamaqua
• One switching the fiddle yard.

I'll run conventional locomotives using the TMCC CAB1 of which I have two.  

Power Center

I learned the idea of a "power cart" from my friends at GCOG (Granite City O-Gaugers club in St. Cloud, MN where I've been a member for ten years or so.  All of the 110vac conversion to layout voltages happens at the power cart and the command control devices are located there too.  For the club's modular layout, it makes a lot of sense since the layout can be configured in so many different ways depending on the show and the location.  

In my basement, I can move the  cart around if I need to and tuck it under the layout when not in use.  I'll be able to make changes to it from a chair instead of having to grub around on the floor under the layout.  I have an old microwave cart in the basement and converting it to a power cart is the perfect use for it.  The cart, which has an upper and lower level and a cabinet below, will contain the following:

• One Lionel postwar Z 250W transformer (lower) providing power to the TMCC Command base, the dimmable lighting bus and directly to the accessory bus that delivers 14VAC to switch machines and other operational accessories.
• One MTH Z750 (lower) MTH DCS Explorer.
• One MTH Z750 (lower) connected to the fixed lighting bus. .
• One Lionel TMCC Powerbase connecting the ZW to the track power bus.
• One MTH Explorer connecting the Z750 to the track power bus.
• One back-up postwar ZW (in the cabinet and not connected).
• I also have a Lionel CW and a KW, which are spares that will be in the cabinet.
• Each of the live components will be plugged into a power strip that will take 110VAC power from the main house circuit. 
• An 8-way connector block will connect the cart to the buses under the layout 

Sub-panels

Four 14ga bus wires will run around and below the layout.  Each section will be connected to the next using an 8-way auto trailer plug to enable individual sections to be disconnected easily.  Each layout section that needs it will have a sub-panel below it, connected to the bus wires.  Fascia-mounted switches and buttons will be connected into the panel and from there get their power.

As of this original post, I intend these sub-panels will be laid out in a standard way to ease maintenance.  There will be a fixed-design area that brings the different circuits into the panel.  In this area will be

• A 6-way black connector block connected to the buses running under the layout. 
• A black 4-way connector block connected to the track and switch machines.  
• A clear Euro-style 12-way connector block connected to the lighting and any non-operational accessories that have lights.

I'm seeking consistency and repeatability which support the TOMA approach and will provide for greater reliability and fault diagnosis.  Piloting a design for the sub-panels is an early goal for the first three layout segments, two of which will need sub-panels.

The non-standard area of each sub-panel will be used for connecting accessories, lighting locations, switch machine connections and block segments to the main bus circuits.  This usage will vary from sub-panel to sub-panel and an individual design document will be created for each sub-panel.

As this wiring gets underway, I'm going to try to avoid soldering as far as I can - I'm really bad at it and plan on using crimp connectors and slide tabs or screws to make the connections.  Our experience with the postwar layout I'm taking down now has demonstrated that this is a reliable method though it will be more expensive and time consuming than simple soldering.

I'll deal with the approach to lighting in the next post.