Lights & Signals
The majority of buildings are fitted with lights. These come from a variety of sources including Patronics for the station lights and Eckon for the yard lights. Other buildings use grain of wheat bulbs. All are powered from a 12v supply controlled via MERG steady state DCC decoders which allow the lights to be computer controlled via the DCC system. I run the grain of wheat bulbs in pairs to make them less bright and prolong their life. Of course, with DCC it is simple to have lights on locos and in coaches, and this is very effective.
Colour light signals are by Eckon and Berco and are driven from the computer control system. Operation is currently set up to be entirely automatic depeding on track occupancy and route settings, the software polls for any track occupancy messages and adjusts the signals accordingly. By knowing about set routes and occupancy the software can also automatically control the signals. These are driven via MERG steady state decoders and relays. Two DCC addresses are used per signal - one is red or not, the other then denotes yellow or green. This reduces the number of addresses required and simplifies the use of common negative signals from Berko and Eckon which are wired via relays. It also means that if there if DCC power is cut, all signals go to red (they are fed from a separate 12v DC supply)
On the opening section there is a level crossing. This has working lights and barriers and is activated from the control computer and interlocked with the signals. The sequence is controlled by a PIC microprocessor which drives LEDs fitted into Peco barriers directly. The barriers are moved by servo motors controlled by a MERG servo4 board which is controlled by the same PIC. There is a video of this that shows the whole operating sequence - click the 'Videos' link on the left.
I have built two signal gantries with theatre indicators which are placed on the approaches to Tedfor and also Bearham. They are not perfect scale models but will give a good representation. A photograph of the prototype on my work bench is below. Construction is brass and plastic. The main signal head is an Eckon 3 aspect unit and the theatre display is built from a surface mount 7 segment display. All wiring is inside the gantry using fine kynar cable:
The layout room is lit with ten GU10 mains haologen bulbs which can be dimmed in two sets, allowing the layout lighting to be seen to best effect.