Abstract: An opening and closing mechanism for a gate which utilizes an electric motor operating through a electromagnetic clutch. The clutch is to be operated at a significantly increased voltage during the initial period of starting movement of the gate. When the gate is rolling, the voltage through the clutch is significantly decreased to a substantially lower level. During this lower level of movement even a minor amount of resistance applied to the gate will cause the gate to stop thereby avoiding injury to animals (including people) and damage to devices such as automobiles. The gate opening and closing mechanism also includes a separate direct drive mechanism which by-passes the clutch when the gate is in the completely open or the completely closed position. This separate direct drive mechanism functions as a positive lock maintaining the gate in its established completely open or completely closed position when the gate is in either of these positions.