Success didn't stop Edison. He continued to look for heat-resistant materials that were stronger and more durable than carbonized cotton. In 188, Edison developed a carbonized bamboo filament lamp, which greatly prolonged the filament life. In October of the same year, Edison set up his own factory in New Jersey and began mass production. This is the world's earliest commercialized incandescent lamp, and Swan of Britain also set up a factory in Benwell, a suburb of new castle, in 1881. The invention of the incandescent lamp is usually attributed to Edison in the United States and Swan in Britain. In Britain, the centenary of the invention of electric light was held in October 1978, while in the United States it was held in November a year later. The competition between the two inventors was fierce, and patent disputes were almost inevitable. Later, the two reached an agreement and jointly established Edison Swan Edison < P > Electric Lamp Company to produce incandescent lamps in Britain.
The modern tungsten filament incandescent lamp was successfully trial-produced by American inventor coolidge in 198. Luminous body is a filament drawn with metal tungsten. The most valuable feature of this material is its high melting point, that is, it can remain solid at high temperature. In fact, the filament temperature of a lighted incandescent lamp is as high as 3℃. It is precisely because the hot filament produces light radiation that the electric lamp emits bright light. Because some tungsten atoms will evaporate into gas at high temperature and deposit on the glass surface of the bulb, which makes the bulb black, incandescent lamps are all made into a "potbellied" appearance, which is to make the deposited tungsten atoms spread on a larger surface. Otherwise, the light bulb will be blackened in a short time. Because the filament is constantly sublimated, it will gradually become thinner until it is finally disconnected, and then the life of a light bulb will be over.
among all lighting lamps that use electricity, incandescent lamps have the lowest efficiency. Only a small part of the electric energy it consumes, that is, 12%-18%, can be converted into light energy, while the rest is lost in the form of heat energy. As for the lighting time, the service life of this kind of electric lamp usually does not exceed 1 hours. At this point, halogen lamps are much longer than ordinary incandescent lamps. Halogen lamps are generally a tiny Shi Ying glass tube. Compared with incandescent lamps, the particularity of halogen lamps is that tungsten wires can "self-regenerate". In fact, the filament and glass shell of this lamp are filled with some halogen elements, such as iodine and bromine. When the filament heats up, tungsten atoms are evaporated and move towards the glass tube wall. The wick of incandescent lamps is tungsten filament. When they approach the glass tube, tungsten vapor is "cooled" to about 8℃ and combined with halogen atoms to form tungsten halide (tungsten iodide, tungsten bromide). Tungsten halide moves to the center of the glass tube and falls on the corroded filament. Because tungsten halide is unstable, it will decompose into halogen vapor and tungsten when it is heated, so that tungsten will be deposited on the filament to make up for the evaporated part. This cycle will prolong the service life of the filament. Therefore, the filament of halogen lamp can be made relatively small and the lamp body is also very compact. Halogen lamps are generally used in places where concentrated light is needed, such as writing desks or local lighting in living rooms.
recently, the Australian government launched a plan to gradually adopt energy-saving fluorescent lighting equipment to reduce greenhouse gas emissions, and incandescent bulbs will be banned from 21. This is the first plan in the world to eliminate incandescent light bulbs. In order to save energy and protect the environment, incandescent bulbs will die!