When I do a sustainability audit for departments on campus, one of the things I look for is "converters" or "chargers" or external power supplies. You know, those big bulky boxy plugs that go into the wall socket and are then connected to the electronic whatever by a thin electrical cord. The cord is thin because what comes out of the converter isn't 120 volt alternating current any more, it's direct current at a much lower voltage. All electronic equipment -- computers, monitors, telephones, etc. -- runs on low-voltage DC.