Originally Posted by c.midland
An Atlas switch will usually turn when a locomotive or car wheel enters it. If the car is very light it might not, but my experience is that any loco will go through the switch even against the points.
A similar issue with a different mfg line. I have a Marx O-34 switch. Mechanically, the frog will move to the correct position for trains entering against the point. But my light tinplate loco derails. It's not heavy enough to move the frog spring.
I have a design using Arduino modules. About $8 per switch. Plug and play electronic modules plus some form factor assembly.
It detects the train entering the switch via isolated rails. Then provides a full voltage pulse to move the frog into piston. The limited duration pulse confidently moves the switch motor but doesn't cause switch motor burnout.
The electronics/switch worked on a bench test. I have not had a chance to test it on the layout.