The ornamental design for a poweradapter, as shown and described.
FIG. 1 is a left side isometric view of our new design for a power adapter.
FIG. 2 is a left side elevation view of FIG. 1.
FIG. 3 is a right side elevation view of FIG. 1.
FIG. 4 is a front side elevation view of FIG. 1
FIG. 5 is a back side elevation view of FIG. 1.
FIG. 6 is a top plan view of FIG. 1; and,
FIG. 7 is a bottom plan view of FIG. 1.
In the drawings, the broken lines shown within the recessed surface in FIG. 3 illustrate portions of the article which form no part of the claimed design. The remaining broken lines illustrate environmental subject matter only and form no part of the claimed design.