How would one hook-up DC ground to the block track? Would you do the same way as if you were using AC ground and just place the DC ground on the outside rail with AC ground? I'm little confused by this and I'm probably over thinking it. I was thinking about using 12 VDC for my block detection, since I will have an ATX power supply for all my Arduinos, Signals, LEDS, and whatever else. I would pretty much not be using the 12V
rail on the power supply, so I might use it. I plan on using all 180W Lionel Bricks for track power. I also have no problem using 14V accessory transformer like Professor Chaos.
I would use an RC circuit with Optocoupler for protection for any AC ground that may try to get into the circuit though. Then the schmitt trigger for debouncing the circuit. How does one size the components for the RC Circuit for both AC & DC (probably the same for both)? I guess with the RC circuit one wouldn't need about current on the Arduino pin or I/O expander correct?
