@Yendor posted:The Old School method was multiple 153C connectors that are spring loaded on the track.
The 145C was a Single action ON/OFF spring loaded connector for things like crossing gates etc.
The 153C was a Double action switch. When it was in the UP (not weighted down by a train) position one contact was LIVE and the 2nd Was Dead, when weighted the Live and Dead Contacts reversed.
By using multiples of the 153C a Train could pull into the 1st Stop Block and the weight would turn OFF Power the that section. However at the Same Time the 2nd Train was moving into it's 2nd stop block. When it arrived it turned Off the Power to it's section but turned the power to the first section back on. As the 1st Train Exited it's stop block and the Contact was Un-Weighted it would turn ON the power for the 2nd Trains Stop Block allowing it to move forward to the next stop block section. This sequence would be repeated usually with at least a 3rd empty stop block in between to keep things from running into each other. The adjustable resistor was used to keep the E-Units engaged so the Neutral & Reverse actions didn't activate, but were available at other points in the tracks or sidings.
I'm not sure an adjustable resistor would work for you as it may not provide enough voltage to power up the sounds without allowing the train to move.
The 153C instructions have a good schematic on this operation.
Thanks Yendor. More to think about and read!
