That looks like an excellent source of parts for the mechanical stuff on the
board. I did one years ago well before any of this stuff was available and
had to make all of the backing plates myself. That was a lot of etching
The workings in the back were CMOS logic which took the track detection (I
used Twin-T type detectors) and turnout positions and determined by simple
logic whether the path was available to the next signal. The operator
pushed a button to enable the route and the appropiate signals went green on
the board and the numerous operator panels about the layout. Turnouts were
thrown from the panel and showed their direction with the lights on the
panel. All power to the circuitry was 12V so 12V lamps were used
everywhere. The CMOS logic drove MOSFETs to light the lamps for the
When the train ran onto the block, the signlas went back to red as the track
detection detected them and told the logic that there was something on that
track. The path enabling button merely put one input into the logic which
fed back to itself to hold the green indication in a simple flip-flop setup.
I don't know if there are any schematics on how to do the basic circuit but
it can get to be a bit complex due to the number of routes that can be
selected but if you just sit down and look at all of the paths and make a
circuit for each of them, locking at the turnout directions, you will be
able to do the job. I took a notebook and made a page for each signal and
wrote down what paths were available and what trackage needed to be checked
for when allowing the signal to go green and it all really became simple in
how it goes together. The complexity is in the sheer quantity of the simple
logic needed to do the job with the many signals that you will have.
Don't forget to make sure that the track between signals (containing the
turnouts themselves) is also detected or you will be routing trains into
other trains. I also locked out any turnouts from actuating when something
was sitting on those little sections of track
There was a lot of electronics there but once it got together, the whole
thing became a real standout on that layout.
Good luck and buy a good soldering iron as you will be needing it!
Why do penguins walk so far to get to their nesting grounds?