Patent ID: 7642676

Claim:
A method of verifying a position of a transfer switch mechanism for connecting a load to one of at least two power sources, the transfer switch mechanism having at least two positions adapted to electrically couple said load to one of said at least two power sources, comprising: measuring a voltage across said load and across each of said at least two power sources; calculating, based on said measuring, one or more voltage characteristics of said voltage across said load and across each of said at least two power sources, said one or more voltage characteristics being at least one of a magnitude, a period, or a phase; determining whether said one or more voltage characteristics associated with said load matches said one or more voltage characteristics associated with any of said at least two power sources, thereby verifying which of said at least two power source is electrically coupled to said load; responsive to said determining, providing data indicating which of said at least two positions said transfer switch mechanism is currently in; and actuating or not actuating said transfer switch mechanism based on said data to change said transfer switch mechanism to the other of said at least two positions.