History : Jul-Aug 2016
84 JULY/AUGUST 2016 son would follow in his footsteps. As a teenager, however, Nikola was stirred by a faith in science and instead studied engineering at the Joanneum Polytechnic School in Graz, Austria. At Graz, Tesla became interested in developing a new electric motor. All motors have two sets of electromagnets. One set is stationary (called the stator) and the other is mounted on a rotat- ing shaft (called the rotor). Adjusting the current fed to each set can create similar magnetic poles facing each other in the stator and rotor. When that happens, the two sets of magnets repel each other, and the shaft of the motor will turn. While watching how a DC motor sparked during a demonstration in his physics class, Tesla suggested that the commutator (the rotating switch feeding electricity to the ro- tor in the motor) should be eliminated. His physics professor thought he was crazy to propose such a motor, but Tesla per- sisted. Over the next few years, Tesla puzzled about how to make a spark- free motor. Rather than build an actual motor, Tesla pictured everything in his TESLA’S SIMPLE LITTLE MOTOR Tesla’s induction motor (below) was at the center of the battle of the currents. Its innovative design and resulting efficiency would revolutionize the power industry in the late 19th century. So, circa 1887, AC looked very promising to electrical engineers. Yet they soon realized that they had an economic problem on their hands. Ideally, an AC system should cover an entire city but that meant that the power plant and network would cost hundreds of thousands of dollars, and to offset that investment, it would be good if the plant could deliver electricity 24 hours a day, 7 days a week. To do that, engineers realized they would need a motor that would consume power during the day—a motor that could be used in streetcars, factories, elevators, and all sorts of applications. Tesla and the AC Motor At this critical juncture—1887—a tall, dark, and handsome man turned up with just the right invention, an AC motor. His name was Nikola Tesla. Tesla was born in 1856 to a Serbian family living in what is today Croatia. Tesla’s father was a Serbian Orthodox priest who hoped his LEBRECH MUSIC/ALBUM CORBIS/GETTY IMAGES THE BIG BUSINESS OF INVENTION T O MANUFACTURE AND MARKET his incandescent lamp, Edison knew he needed the infrastructure to support it. He designed an entire system to power the light bulb, but he didn’t stop there. A savvy businessman, Edison founded companies to manufac- ture all the parts needed for his DC sys- tem in the early 1880s; he established the Edison Lamp Works, which was renamed the Edison Electric Lamp Company, Edi- son Machine Works (left), and several other companies to produce lamps, gen- erators, conductors, and meters. Despite losing the battle of the currents over the next few years, Edison’s companies en- dured. In 1889 they combined to form Edi- son General Electric, which subsequently became General Electric.