Tuesday, April 24, 2012

Edison's Revenge: The Rise of DC Power

In a world of more electronics and solar energy, there's less and less need for AC power
Thomas Edison posing with a phonograph. The inventor was also a pioneer of early electrical systems, and advocated for direct current.

April 24, 2012 - In 1903, as a last-ditch effort to maintain direct current as the standard for distributing electricity around the United States, Thomas Edison presided over a notorious event meant in part to demonstrate the danger of alternating current: the electrocution of Topsy, a circus elephant deemed a threat to humans, by a 6,600-volt AC charge. Edison's stunt was pure fear-mongering (DC being equally dangerous at high voltage), and it failed: our grid today is primarily AC.

But a little over a century after Topsy's collapse, it is AC that looks increasingly wobbly. Thanks to growing power consumption by digital devices of all kinds, DC power is making a comeback, this time on its own merits.

Anything that uses transistors relies on direct current, the flow of electricity in one direction. That explains why PCs, iPhones, and flat-screen TVs all have converter boxes to turn the alternating current in wall sockets (which reverses direction 120 times a second) into direct current. read more>>>

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