Abstract: A power adapter has a main body of cylindrical shape. A top of the main body defines a recess and an annular sidewall enclosing the recess. A rotation-proof component received in the annular sidewall of the main body defines a rotation-proof portion extending into the recess. A plug is rotatably mounted in the recess, and a side of the plug defines at least one rotation-proof recess. The plug is rotatably secured in the recess then the rotation-proof portion is elastically pressed against the plug and finally the rotation-proof portion is released into the rotation-proof recess for restraining the plug from reverse rotation.

Abstract: A power adapter has a main body. A top of the main body defines a recess and an annular sidewall enclosing the recess. The recess has a locating depression arranged at a bottom thereof to be deviated from the center of the bottom. A plug is rotatably and detachably mounted in the recess. An elastic component mounted in the plug defines a contacting portion elastically protruding out of a bottom of the plug. The plug is locked in the recess by rotation so that the contacting portion is pressed against the bottom surface of the recess and compressed back elastically and then the contacting portion engages the locating depression under resilience action of the elastic component for preventing the plug from rotating with respect to the main body.

Abstract: A power adapter has a main body. A top of the main body defines a recess and an annular sidewall enclosing the recess. The annular sidewall has a sliding recess extending along the circumference of an inner surface thereof. A rotation-proof component defines a rotation-proof portion received in the sliding recess. A plug rotatably and detachably mounted to the main body defines a protruding portion at one side thereof. The protruding portion is capable of reciprocally sliding in the sliding recess and elastically pressing the rotation-proof portion for passing through the rotation-proof portion and then being restrained from reverse rotation because of restoration of the rotation-proof portion.