Franklin Christmas 2008 Display Controller
Revised 10-21-08


The objective of this project is to design and construct a controller that will activate two trains when visitors press a button on the outside of the display window.  The button will be connected to a radio control transmitter which will activate a matching radio control receiver inside of the controller.

The controller will have a timer (Omron HC3A) that will be set to run the two trains for some amount of time each time the button is pressed.

Rather than having the controller make / break 110 volt power connections to the two train's power supplies it will break the low voltage power that each power supply sends to the track.

One train will be on a loop of track and will proceed forward whenever the button is pressed. 

The other train will be on a point-to-point layout and will go back and forth under the control of a BARC controller whenever the button is pressed.  Note that no attempt will be made to remember the position of the train when it stops so that its first movement upon being restarted may be in the opposite direction from the way it was moving when stopped.



Controller Schematic & Notes

Power for the controller will come from the AC out connections on the MRC 6200 power supply.  One track power lead from the MRC 6200 will go directly to the track while the other lead will go into the controller via terminal 3 and to the track via terminal 5.  This connection will only be live to the track when the system is operating.

The other power supply will go to the BARC.  One of the track connections from it will go directly to the point-to-point track while the other will go into the controller via terminal 4 and to the track via terminal 6.  Again, it will only be live during the time that the Omron timer is active.

An optional counter (from a pedometer or similar unit) can be connected to terminals 7 and 8 and will increment each time the button is pushed.  It is activated by a small SPDT relay that is wired in parallel with the DPDT power relay.

The controller will be housed in a 4" x 4" x 5" plastic enclosure with the Omron timer coming out of the top.  On top will also be the connection strip, a start button and a reset button that will stop the trains.  Inside of the box will be the Omron timer, the radio control receiver / relay, a power supply with two filter capacitors and a DPDT relay that will activate the trains.

Outside Transmitter Box

A locked box will house the transmitter and a large, robust button that will be used to start the trains.  The transmitter will be battery operated.

The box will be affixed to the outside of the building by screws.

Completed Controller

The device in the lower right is a 7812 voltage regulator that is screwed to the large metal case of the bridge rectifier.