I was having trouble getting my trains to load the plastic fast enough, so I made two stations one after another. The second station is only active when there's a train in the first
Because without circuits, trains would just always take the closer one, so the top station would be pointless. Now, two trains can load off one track at the same time
@DJMcMayhem To clarify, "second" is on the bottom, and "first" is on the top
Probably my favorite/most useful circuit creation yet is a switch that can shut down whole sections of my factories when power usage drops below X% and turns them back on when they go above Y%.
