Automatic Signalling using optical detectors for train detection is also possible. These can be used to control a block of track, a signal at one end is green and the other red, once the train passes the green signal both signals are red until the block is cleared. As the train approaches the red signal (with the block clear) the far signal will change from green to red and after a short delay the signal in front of the train will turn to green for the train to proceed. This could also be used with the servo controller for semaphore signals.
My newer signal controller [3.4] is now available, this model can operate both common positive or common negative LED signals user selected on the board. It also now has a trimpot to adjust the timing. This new model also has current limiting resisters on the board to protect your LED signals and a simpler layout.
Instructions and explanation of operation for 2 Aspect Signal Control [3.4] downloaded here.
My original signal controller [2.0] is still available, this model can operate only common negative LED signals. Please note current limiting resisters are required to be added to there output to protect your LED signals. (I suggest 150r to 220r resisters per each Green and Red output.)
Instructions and explanation of operation for 2 Aspect Signal Control [2.0] downloaded here.
The price for both signal controllers for 2 aspect lights is $60 (plus $10ea for optical detectors) and user configured for any of the signal applications in the Instructions.
With the addition of the 2 position 2 Servo controller it can also be used to automate Semaphore signals.
A signal controller for more prototypical signals is in development. Modellers suggestions are most appreciated on the features that would enhance you models. Signal Planning Victorian Railways.