Abstract: A power adaption device includes an electrical cord assembly and an adaptor plug assembly. The adaptor plug assembly includes an electrical conduction member and a tightness adjustment member. The electrical conduction member is formed with an insertion hole and an adjustment hole in communication with each other. The electrical cord assembly is insertable into the insertion hole to electrically connect the electrical cord assembly with the electrical conduction member. The tightness adjustment member is screwed into and connected to the adjustment hole to abut the electrical cord assembly. As such, firmness of connection between the electrical cord assembly and the adaptor plug assembly can be enhanced.

Abstract: Described herein is a rotary coupling structure which comprises a fixing base and a rotary coupling plug; and the fixing base comprises a mounting member and a rotating member; the mounting member comprises a sleeve provided on the inner wall with a lock slot, a limit buckle disposed at the end of the sleeve, and a side boss disposed on the side wall of the sleeve; the rotary coupling plug, configured to be inserted into the sleeve and connected with a connector, is provided with a rotary lock blade rotatively disposed in the lock slot.

Abstract: The present invention discloses a rotary coupling structure, a power supply device and a sofa, which comprise a fixing base and a rotary coupling plug; the fixing base comprises a mounting member and a rotating member; the mounting member comprises a sleeve provided on the inner wall with a lock slot, a limit buckle disposed at the end of the sleeve, and a side boss disposed on the side wall of the sleeve; the rotary coupling plug, configured to be inserted into the sleeve and connected with a connector, is provided with a rotary lock blade rotatively disposed in the lock slot.

Abstract: The present invention discloses a combined power supply, including a lithium battery and a base which are detachably connected. A power-switching circuit is provided in the base. The base further comprises a stand-by battery which is detachably connected to the base.