Le 22 février 2017, 07:38 dans Humeurs • 0
By the late 1920s and early 1930s, European researchers were doing experiments with neon tubes coated with phosphors (a material that absorbs ultraviolet light and converts the invisible light into useful white light). These findings sparked fluorescent lamp research programs in the U.S., and by the mid and late 1930s, American Ceiling Lights companies were demonstrating fluorescent lights to the U.S. Navy and at the 1939 New York World’s Fair. These lights lasted longer and were about three times more efficient than incandescent bulbs. The need for energy-efficient lighting American war plants led to the rapid adoption of fluorescents, and by 1951, more light in the U.S. was being produced by linear fluorescent lamps.
It was another energy shortage -- the 1973 oil crisis -- that caused lighting engineers to develop a fluorescent bulb that could be used in residential applications. In 1974, researchers at Sylvania started investigating how they could miniaturize the ballast and tuck it into the lamp. While they developed a patent for their bulb, they couldn’t find a way to produce it feasibly. Two years later in 1976, Edward Hammer at General Electric figured out how to bend the fluorescent tube into a spiral shape, creating the first compact fluorescent light (CFL). Like Sylvania, General Electric shelved this design because the new machinery needed to mass-produce these lights was too expensive.