Coffee Table #3 Design
Note: The links on the left side of this page and the other Model CT-3 pages will take you to detailed information about the new coffee table's design and construction.
The electronics for Coffee Table #3 consists of a freestanding touch-screen Tablet PC, various off-the-shelf model railroad controller and sensor modules, a few custom-designed circuits, and various power supplies. In other words, Coffee Table #3 is similar to the Test Track, except that the coffee table has more of everything.
The majority of the electronics, except for the Tablet PC and power supplies, are produced by CTI Electronics.
All electronic equipment except for the Tablet PC is located under the layout in the base of the coffee table. Most of the circuits, including power supplies, are mounted in a wooden “equipment box” that is fastened to the inside of the table. Some of the smaller electronic modules—primarily the special effects modules—are mounted on the underside of the layout, itself, or in the tunnel. The electronics in the equipment box are connected to the layout via four 40-pin extra-long computer cables. Communication between the electronics and the Tablet PC is via a standard USB cable.
The photo below shows an exploded view of the entire assembly, including the lift mechanism that raises the layout to the top of the table. Note that the mountain top in the layout is open, exposing the tunnels and some additional electronics.
A closer look at the equipment box—with the lift platform removed—shows the arrangement of electronic circuits and power supplies (photo below). The electronic modules are mounted on two long white removable boards, while most power supplies are mounted underneath. Two small exhaust fans with aluminum ductwork can be seen on either side of the equipment box. Stereo speakers (black boxes) can be seen at the top and bottom of the photo, outside the equipment box.
The underside of the layout is shown in the next photo. The green Tortoise slow motion switch machine at the top of the photo controls the crossing gates in the layout's main town. Various Peco turnout motors (switch machines), and special effects controllers are scattered throughout the underside of the layout. At the bottom of the photo, the four green cable connectors can be seen, as well as the terminal strips to which they are connected.
More information about wiring and packaging of the layout's electronics is available here.
The specific CTI modules used in Coffee Table #3 include:
Other controllers and sensors
Several non-CTI controllers are used for special effects throughout the layout. These include:
New special effects are being evaluated on a continuing basis. As recently as August 2014 two new Miller Engineering animated signs were being added to the layout.
Eleven power supplies provide power to the layout.