Patent attributes
An AC cord/plug is “dead” while disconnected and goes “live” only when connected. The plug has a set of spring-loaded, normally-open contacts, each having two sets of fixed contacts and a single set of movable contacts. The movable contacts are in a spring-loaded assembly that has an iron core opposite the contacts, and the fixed contacts are in a hermetically sealed compartment shielding them from the plug's exterior. The AC plug inputs (L1, L2) are connected to one set of the normally open, fixed contacts, and the plug's socket terminals are connected to the other set of normally opened, fixed contacts. In the unplugged state, the plug's socket contacts are electrically isolated from the L1 and L2 inputs. When plugged-in, the plug's socket terminals go “live” when a magnetic circuit closes between the plug and socket that causes the plug's spring-loaded assembly to move to close the contacts.
