The ornamental design for a poweradapter, as shown and described.
FIG. 1 is a perspective view of a power adapter showing my new design;
FIG. 2 is another perspective view thereof;
FIG. 3 is a front view thereof; the rear view being a mirror image of the front view;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof;
FIG. 8 is a reference perspective view thereof showing a cable fixed on the power adapter; and,
FIG. 9 is another reference perspective view thereof showing the cable fixed on the power adapter.
The broken lines shown represent unclaimed subject matter only and form no part of the claim. Where broken lines abut a claimed surface it is understood that those broken lines represent an unclaimed boundary between claimed and unclaimed surfaces. None of the broken lines form any part of the claimed design.