Our intention with Lyghtondown has always been to operate it as a DCC layout, and the consequences of this choice were largely explored prior to the track being laid.  As a result much of this Blog entry really overlaps the previous entry as track laying and train control happen hand in hand. But to continue ...

In hindsight some inevitable inexperience crept into the decision making progress, though largely nothing which cannot be carefully re-examined if necessary.  Our thinking broadly touched upon the key "advertised" benefits of DCC:

• A two wire Bus architecture for power and control
• No need for isolated sections of track
• Point motors driven and operated from the bus
• Accessories (signals etc) driven from the bus

So (we thought) in the catch phrase of that advert: "Simples".

Step one was to convert all the points from DC function to DCC only: Short bridging wires were soldered onto the underside of each point so that the point blades ceased to be a functional electrical switch and the over centre springs on the tie-bar were removed (in preparation for the point motors):

in addition to this all the conducting fish-plates we used in the track had drop lead soldered onto them and fed down through the base board:

Then, where the track crossed base board boundaries, we put in small brass screws and used these to both fix the rails in position and also to supply power to the rail ends:

This being done with the rail continuous across the gap, then slitting the rails with a 0.5mm Dremel diamond wheel.

Then, finally, wire the whole lot up into some electricians idea of a nightmare birds nest of wires:

Actually, I like to think that is a little better than that.  At the moment the infamous "choc blocks" have been used as these are easy to undo or extend while we have been "developing" the wiring solution.

A key early decision was to have the capacity to route six wires between all the boards.  The rational for this was simple:

• DCC to rails for engines (blue/yellow)
• DCC to accessories (purple/grey)
• Pure DC 15 volt power (red/black)

These six wire use some readily available automotive 4 amp connectors to bridge the boards:

However as can been seen from the photos above, so far we have only connected and utilised the track DCC bus (blue and yellow wires).  We have found that even with all the point motor attached and two engines running the whole system only draws 0.5 amps. There seems to be little reason to to make it more complex than it needs to be (but being prepared is never a bad idea).

What else to say of note?

• The point motors are all from DCC Concepts.  Like the track these (quite a lot of them) were bought when the boards were built.  There is much I could say about them, but not here.  In simple terms they do operate the points under DCC control, and they do supply the frog with a feed from either the blue or yellow wire they are powered from (this is probably a very good reason to run them off the track bus).
• It's tempting to think that as the track is a complete loop and that the DCC bus will be too.  It is not.  There is a clear electrical break at one end of the traverser with power supplied into the bus next to that break.
• I have not installed any DCC bus terminators or suppressors .. yet.  The system seems to be operating reliably over all the track.  This could be a function of the size of the whole layout (being smaller giving less opportunity for issues) or just the equipment being used.

For practical purposes the layout has stayed at this point, electrically speaking, since this time.  Once some of the more interesting ideas we've had brewing on the back burner get some time "up front" then I expect some changes and extensions to the wiring will be required, but all hopefully within the scope of what's already in place.

All this, of course, is of no value without a source of power. Coming next.

Jeff.