Why did Edison invent the light bulb

Reason: At that time, because the basic technology of electric lamp was immature, the battery used for power supply had poor performance and low voltage, and vacuum technology was not developed. Swan's electric lamp not only has no practical value, but also has poor performance. Poor vacuum technology will always make carbon wires burn out quickly.

To this end, he has been improving his invention and studied it for 12 years. The bottleneck of durability has not been broken, and the experimental work was completely put down in 1860.

Swan, who stopped studying electric lights, was not idle. He has dabbled in a wide range and has become a minor celebrity in local academic circles. He was also promoted from assistant to partner in a photographic plate manufacturing company, and improved the wet printing method of collodion at that time.

Swan designed a dry photographic master, using nitrocellulose plastic instead of the tedious steps of preparing nitrocellulose solution on site. 15 years later, this technology inspired Eastman in the United States, who later founded Kodak Company.

Thomas Alva Edison bought the 1875 patent of Henry Woodward and Matthew Evans.

Based on this design, an improved carbonized filament was invented. Edison put the filament in a vacuum bulb, which can burn continuously for the first time 13.5 hours, and can burn continuously for 40 hours later.

Extended data

During the period of 1880, Edison sent assistants and experts around the world to find suitable bamboo. There are about 6,000 kinds of bamboos, among which carbon fibers made of Japanese bamboos are the most practical and can last for more than 1000 hours, thus achieving the purpose of durability. This kind of lamp is called "carbonized bamboo filament lamp".

188 1 year, at the Paris World Expo, Edison exhibited a 27-ton power generation equipment, which could be illuminated by 1200 electric lights. 1883, Edison observed that a copper wire was sealed separately in the light bulb during an electric lamp test, and thought that this could prevent the carbon wire from evaporating and prolong the life of the light bulb. After repeated experiments, the carbon filament evaporated as before.

However, from this failure, he found that a weak current passed through the copper wire after the carbon wire was heated. Later, this phenomenon was called "Edison effect". 1904, the British physicist Fleming invented the electron tube according to the Edison effect.

Baidu Encyclopedia-Thomas Alva Edison