Thanks for all the great new information. I was able to finish what I had to do by manually opening and closing the gate. Not fun, but made it work. Now I have more time to devise the system.

 Surplus center sells the actuators without the switches. They have a clutch to protect against over run, but the one model that I have on hand, has no limit switch. I did find that they offer the same size in a model with switches and a controller for it that is programmable. So the switched model must also have a potentiometer in it?