Door won't go digital
Thanks again Carl,
The limit switches are located in the box, they run on a screw turn which is linked to the motor on the door. I don't want to run extra sensors or switches with cable. The point was to not have to replace parts that are "up in the air" a real safety issue.
I think the digital garage openers are using solid state programmable timers, but it looks like they might be using "Smart motors" as well as logic control. Looks like my door might be left in the "good old days".