The ornamental design for a poweradapter, as shown and described.
FIG. 1 is a front, right, and top perspective view of a power adapter, showing my design.
FIG. 2 is a rear, left, and bottom perspective view thereof.
FIG. 3 is a front elevation view thereof.
FIG. 4 is a rear elevation view thereof.
FIG. 5 is a left side elevation view thereof.
FIG. 6 is a right side elevation view thereof.
FIG. 7 is a top plan view thereof.
FIG. 8 is a bottom plan view thereof; and,
FIG. 9 is a perspective view of the power adapter of FIG. 1 wherein a plug of the power adapter is protruding out of a main body of the power adapter.
The broken lines shown in the drawings are included for the purpose of illustrating portions of the power adapter that form no part of the claimed design.