天才テスラの交流発電／The Genius Tesla and AC Power

DENJIRO: Today, I’m going to introduce to you a man who made immense contributions to the field of electricity. Nikola Tesla (1856-1943) was a late-19th century inventor from present-day Croatia who was a rival of Thomas Edison. He was involved in developing something very important for our daily lives. Take a look at this device. This is a model of an electric generator that Tesla invented. There are four coils. The coils are connected to LED lights. In the center are magnets. If you spin these magnets... GIRL: The lights turned on! DENJIRO: You can see the green and red LED lights alternating. This is a two-phase electrical power generator invented by Tesla. This is a very important means of generating power as it is the foundation of power generation and transmission systems used today. Let me use a part of this generator to explain how AC electrical generation works. I have LED lights attached to a coil here. Let me bring a magnet up to it, pull it away, then repeat that motion. As you can see, moving a magnet close to the coil generates electricity, and the lights turn on. You can see that the lights alternate. The LED arrows show the direction of the current. When the magnet approaches the coil, electricity runs in the direction of the red arrow. When the magnet moves away from the coil, electricity runs in the direction of the green arrow. As you can see, the direction of the current alternates. This is how AC electrical generation works. Tesla used two pairs of coils to create waves of alternating currents. This is two-phase electric power. Tesla proposed a transmission system that used this idea. NARRATOR: Tesla’s AC electrical generation, compared to Edison’s DC electrical generation, is better for carrying more electricity to a faraway location. As a result, the electricity generated in a power plant that is sent to homes is AC. The AC electrical generation that Tesla proposed supports our daily lives. DENJIRO: I hope energy will bring you all happiness. Our magic word is "Happy Energy!"