Abstract: An extension cord includes a body for connecting a two-slot socket to a three-slot socket, a detecting circuit electrically connected to the body for detecting a hot wire and a neutral wire of the two-slot socket, and a grounding circuit electrically connected to the body and mounted between the neutral wire of the two-slot socket and a grounding slot of the three-slot socket. The extension cord further includes a cable covered with a metal wire-weaved net for electrical connection with the two-slot socket. The detecting circuit includes a slide switch and an indicator. The slide switch includes a metal housing. The indicator is electrically connected in series to a resistor. The grounding circuit includes a resettable positive temperature coefficient electric fuse or a meltable fuse.

Abstract: An electric appliance/extension cord assembly includes an electric appliance and an extension cord. The electric appliance includes a body having a plug with three prongs. The body further c includes a housing and a shielding conductive layer in the housing. The shielding conductive layer is electrically connected to a grounding prong of the plug of the electric appliance. The extension cord includes a casing and a plug. The casing includes a plurality of three-slot sockets. The plug of the extension cord is coupled with a two-slot socket. The plug of the electric appliance is coupled with one of the three-slot sockets of the extension cord. The extension cord further includes a detecting circuit for detecting a hot wire and a neutral wire of the two-slot socket.

Abstract: An advanced ventilator vane structure comprises multiple vanes set equidistantly on the same surface of the center of a base. The tortuosity of each vane is like S-type shape and its free end is an arc fringe. This special shape of the vanes could reduce the wind resistance and the turbulence, as well as the noise caused by resonance. This invention achieves the purpose of improving the economic efficiency via enhancing wind-force by increasing the rotary power and the speed of the vane.