1700 or so, scientists discovered the principle of charge and invented the Leiden bottle. On this basis, Benjamin Franlin, the founder of the United States and one of the signatories of the Declaration of Independence, discovered that electricity and lightning on the ground were the same thing through experiments in 1752, thus inventing the lightning rod. The English name of the latter is lightning arrester, which means this; Franklin made great contributions to the political, economic and human civilization process of the founding of the United States, and his head is on today's hundred-dollar bill;
/kloc-at the end of 0/8, Italian Volt invented the lead-zinc battery, and today's voltage is in his name.
180 1 year, the British chemist David electrified the platinum wire to emit light. 10 years later, he invented the electric candle and used arc lighting between two carbon rods, but both the expensive platinum and the inefficient arc lighting technology kept them away from the public.
Around 1820, the Englishman Faraday invented the DC generator, and after 10, electromagnetic induction was discovered, which produced alternating current. It can be said that human beings have been liberated from manual machinery since then. Today's Faraday's Law is a compulsory course in our senior high school.
While Faraday was studying power generation equipment, on the other side of the Atlantic, the German watchmaker Henri Goebbels (Heinrich G? Bel) discovered a more effective carbonized bamboo filament material, and used a vacuum bottle to guide light, which was the first electric lamp with practical value. 1854, Henry's light bulb continued to light for 400 hours, but he did not apply for a patent in time;
1860, joseph swan, an Englishman, also made a carbon filament lamp, but he failed to obtain a good vacuum environment to make the carbon filament work for a long time. 10 years later, with the development of vacuum technology to meet the needs, he invented a light bulb powered by carbon wire under vacuum. Unlike Henry Goebbels in the United States, Swan applied for and obtained a patent. His own house was the first private house with electric lighting in Britain.
At the same time with Swan, two Canadian electrical technicians applied for the patent of electric light. They filled the glass bulb with nitrogen to make the charged carbon rod glow.
1880, American Edison improved and manufactured a carbonized bamboo filament lamp that could last for 1200 hours.
The light bulb was invented, but two major problems have not been well solved. 1. Material of filament 2. Photoelectric efficiency; The former was not solved until Edison invented the tungsten filament bulb in 1906: the melting point of tungsten is as high as 3000 degrees, and the effective use time (without fuse) in vacuum is as high as 1000 hours, so the physical design can make the bulb miniaturized and introduce it into residential buildings; The latter is that only 10% of electric energy is converted into light energy, and this short board of incandescent lamp has been greatly improved until the invention of fluorescent lamp 30 years later (the photoelectric conversion rate is increased to 40%); 1998, although the invention of LED lamps only slightly increased the conversion rate to 50%, the indicators such as power saving (cold light), service time and maintenance cost were greatly improved;
In fact, in the second half of the 20th century, various incandescent lamps were widely developed for different occasions, such as:
-Ordinary incandescent lamps (mainly for domestic use)
-Tungsten halogen lamp-gas-filled incandescent lamp, the filling gas contains some halogen elements (used in conference rooms or exhibition halls)
-Low-pressure discharge lamps (i.e. fluorescent lamps)
-High intensity gas discharge lamps (road lighting, indoor and outdoor industrial lighting)
-High-pressure sodium lamp (commercial lighting)
-Low-pressure sodium lamps (lighting in tunnels, ports, docks, mines, etc.). )
-High-frequency electrodeless lamps (public buildings, shops, tunnels, pedestrian streets, high-pole street lamps, safety lighting)
It is worth mentioning that American Edison is famous for inventing and popularizing electric light, but in fact Edison is more of a capitalist than his own research and invention. In addition to being suspected of encroaching on other people's patents, he also bought many other people's patents:
-1870, the U.S. patent office ruled that Edison's carbon filament incandescent lamp was invalid after it fell on people; After years of litigation, Henry Goebbels won the patent, but finally Edison bought the patent from Goebbels' poor widow and improved it into a bamboo filament incandescent lamp.
-At about the same time, the Englishman Swan also accused Edison of patent infringement, and later reached an out-of-court settlement. They set up a joint venture company, but in the end, Swan sold his shares and patents to Edison.
-1875, two Canadian electricians who invented injecting nitrogen into a vacuum bottle found that they didn't have enough money to continue to improve their invention, so they sold the patent to Edison.
-1884, Serbian nikola tesla immigrated to the United States, and Tesla, eager for American identity, joined Edison's company. Unlike his boss, who is good at business operations and has a good reputation, Tesla is only immersed in inventions and never considers making a fortune with his own patents. During his work, Edison promised Tesla to help him improve the generator and pay him $50,000, but Edison failed to honor it, which led Tesla to leave. Tesla is one of the main inventors of AC motor and the inventor of radio technology. He was unmarried all his life and died in a hotel in new york before the victory of World War II. As long as he insists on charging royalties of $2.50 per horsepower, he will be the richest and most prestigious person in the world. Today, Musk's electric car company is named after him!
In order to get rid of the eternal darkness, many wise men have made efforts and wisdom, which has brought us light and progress. Thank them!