Abstract: An electrically activated parking brake can include a constant power motor for actuating a cam that is connected via a cable to the parking brake. The cam has a variable radius perimeter such that a roller follower or linkage operably engages the cam by rolling along the perimeter of the cam. The follower will move radially outward from the center of rotation, as the cam rotates in a positive direction. A cable is operably attached to the follower and to a cable mechanism operably associated with a brake system on a wheel. The brake system applies the brakes when the cable or linkage is pulled by the follower after the cam rotates a full cycle.