Early electric lights and motors ran on direct current (DC) produced at a nearby generating facility. Transmitting DC power over a substantial distance, however, presented certain problems. Much of the electricity dissipated from the wires before it reached distant customers. Raising the voltage could deliver functional current at the far end of the line, and manufacturers marketed equipment capable of producing 5,000 volts, but the generating machines possessed a fatal flaw. Their weak link was the commutator, a spinning device with sparking brushes that wore out quickly when running continuously at high voltage. . |