As the story goes, the rock band AC/DC took its name from a label on an old sewing machine in the Young brothers’ home. It must have meant that the machine could run on either alternating-current or direct-current electricity. Today, all the newfangled electronic devices in our homes run only on DC power—even lighting fixtures, now that LEDs have replaced incandescent bulbs.
But wait. The electricity that comes out of your wall socket is alternating current. That means each device needs to convert AC power to DC, as well as reducing the voltage to the much lower levels used in digital circuits. So you might well ask: Wouldn’t it make