Single dwell with dyad

This is a Single Dwell mechanisms in which a dyad remains stopped whill point P of the coupler goes along a nearly round part of it's trajectory

-Move the point A and observe that point P (red point) describes  a trajectory nearly that a circumference -L2=L3=L4 -The point O is the center of the circumference -While point P(red) translates along the piece of the curve that is  almost an arc of circunference, point C remains stopped in the center of the circunference, and therefore, the crank of the dyad remains stopped -Move point D to make a design with a different dyad