How did Edison invent the incandescent lamp?

1. the eve of the electric light age

In ancient Greek mythology, human beings were created by Prometheus. He also served as a teacher for human beings, teaching them all useful knowledge that can make them satisfied and happy. Similarly, human beings also thank and repay him with love and loyalty. But Zeus, the highest god, asked human beings to worship him, so human beings must give him the best things. Prometheus' behavior offended Zeus.

As his punishment, Zeus refused to give people the last thing they needed to complete their civilization-fire. But Prometheus thought of a way to steal the fire with a long fennel branch and bring it to mankind when the burning sun car passed by. Fire changed human history, steam promoted the industrial revolution, and electricity brought a new era.

The electric light is the most famous invention at the end of 19.

Among Edison's 2,000 inventions, the most important and brilliant are electric light and power distribution system. It was Edison who brought light to mankind. When Edison began to study electric lamps, natural gas lamps were widely used in ordinary families. The invention of natural gas had a history of 70 years at that time, which replaced the previous oil lamps and candles and developed rapidly.

But to use natural gas lamps, every household has to install natural gas pipelines to supply natural gas, so it can only be used in cities, and most people in the United States don't need it. On the other hand, the research on electric lighting has been going on. Before the electric light appeared, people had mastered the knowledge about electricity. The first person who started this research was British scientist David. 1808, David connected 2000 batteries to do experiments, and tied carbon rods on the iron wires protruding from the batteries. At the moment when the carbon rod touched the iron wire, a strange phenomenon happened: there was a strong light between the two carbon rods, which was incomparable to kerosene lamps and natural gas lamps. So David immediately thought of the electric light. He wants to use electricity for lighting. After long-term unremitting research, such a kind of lighting lamp was invented, called arc lamp.

However, the arc lamp is very rough, and the carbon rod is very easy to wear and needs to be replaced frequently, which is inconvenient to use. Its light is so strong that it can only be installed in streets or squares, and it will go out within a few hours. At that time, ordinary families still used kerosene lamps or gas lamps. It can't spread to every family, but it is with this opportunity that the research on inventing more convenient electric lights has been put on the historical agenda.

2. The boyhood of the "invention king"

Edison 1847 was born in Mylan, Ohio, USA. His father runs a wood processing factory. Edison is the youngest of four children. Edison, the great inventor, was a child who was curious about everything since he was a child. In order to hatch goslings, he once hatched goose eggs like a mother goose; In order to make people fly into the blue sky, he made his friends drink sour, which almost caused great disaster. When I was a child, Edison was regarded as a "mentally retarded child" by the school teacher because he liked to find roots, and was taken back by his mother. Therefore, Edison's whole school life was only three months.

Edison learned a lot from his mother, more than ordinary primary school courses. Under the enthusiastic education of his mother, little Edison made rapid progress in his knowledge. Once, my mother bought a book called "Academy of Science" for little Edison. That book records many scientific experiments. After reading carefully, little Edison did every experiment. Since then, Edison has gradually become an experimental madman. In his childhood room, many scientific books and experimental equipment were randomly placed.

When Edison 12 years old, there was a steam locomotive in his hometown. Due to the financial difficulties of his family, little Edison heard the news of recruiting a newspaper salesman on the train and immediately applied for it. From then on, he became a newsboy on the train. After selling the newspaper, Edison spent the rest of his time reading. Little Edison had another brilliant idea. He asked the familiar conductor to turn a small part of the bus into his own room. He moved out all the experimental equipment at home and opened a laboratory there.

Because there was a civil war in the United States at that time, people were particularly concerned about current affairs. Little Edison had a very good business selling newspapers on the train. Two or three years later, he edited a Pioneer Weekly on the train, and even the British Times reprinted its news. In his spare time, he studies hard and conducts various scientific experiments. One day, because the train shook too much, a bottle of yellow phosphorus on the shelf fell to the ground, causing a fire. Fortunately, the fire was put out in time. The conductor got angry, threw all his instruments and medicines out of the car, and slapped little Edison three times, making his left ear deaf.

/kloc-at the age of 0/5, Edison rescued the son of Mackenzie, the stationmaster and telegraph operator, from a car accident on the railway. In return for Edison, Mackenzie promised to teach him telegraph technology. Before long, he became a telegraph operator at the station. /kloc-at the age of 0/6, Edison invented the automatic transmitter. It is because of this automatic transmitter that he was denounced as "greedy and lazy". In the following years, Edison changed jobs many times, and was often dismissed because he was considered "doing nothing" about invention and reform.

Edison 2 1 year old. He went to Boston. Among more than 1000 invention patents obtained in his life, the first invention was born in Boston. He obtained the patent of "automatic electronic voting recorder" in Boston.

1870, Edison bought a workshop in Newark, New Jersey, and began to produce his own stock market automatic recorder. Edison succeeded this time and made a lot of money. 1876, 29-year-old Edison founded a new research center-"Monroe Institute" in Monroe Park, 40 kilometers away from new york. This pioneering work is not only of immeasurable significance in Edison's life, but also the first industrial research institution in the United States and even the world, marking the beginning of collective research and setting an example for the United States and other countries in the world to establish large-scale industrial research institutions.

3. Edison's family life

Mary Stilwell was Edison's first wife. She met Edison when she was working in the Newark factory, and she knew the young man she was going to marry very well. 1884, Mary died of typhoid fever.

Edison's second wife Mina Miller married Edison at the age of 20. At first, Edison's parents didn't support the marriage because of her age difference. Edison taught Mina Miller to use codes so that they could communicate in secret language.

Mary lets her husband work, dress and eat as he pleases. Mina tried to correct her husband's careless behavior and pointed out that smoking and spitting are not allowed in civilized society.

4. Attack electric lighting

Edison thought, "if only every household could use electric lights!" " "

1in September, 878, Edison really captured the fortress of electric lighting. As soon as the news spread, it immediately sensationalized the whole United States and Britain, causing the stock of London Gas to plummet.

Edison began to devote himself to intense scientific experiments. He started by experimenting with incandescent lamps. The principle of this lamp is to put a small piece of heat-resistant material in a glass bulb and connect it to the power supply. When it burns to a white-hot level, the glass bulb will glow when heated. According to this principle, Edison thought that if we want to do experiments well, we must first find suitable heat-resistant materials.

One night, Edison sat at his desk, turned on the gas lamp, took out paper and pen, and wrote out all the heat-resistant materials he could think of. Finally, he counted 1600 kinds. The next day, he arranged manpower to prepare these materials. Then, experiments are carried out in different categories; At the same time, he used his brains in the structure of the electric lamp, constantly improved the pumping method, and strived to achieve absolute vacuum in the glass bulb. During this period, Edison racked his brains and tried his best to forget all about eating and sleeping, working day and night, but always failed to achieve the expected results.

It was not until June 1 879 65438+1October1that Swan reported carbon filament as a filament in Scientific American magazine, and the carbon filament bulb was redeveloped. He also wants to build a system consisting of generators, wires and cables to provide electricity for everyone like a natural gas pipeline network. Edison's research on electric light was funded by many capitalists, which enabled Edison to devote himself to this research.

5. Attempt of various materials

In 1978, Edison had studied the electric light. At that time, charcoal was burned with paper, divided into thin strips, and then electrified to glow. But it was carried out in the air, and the carbon wire burned out immediately, because there was no vacuum valve at that time, and a vacuum environment could not be created. In addition, Edison tried platinum wire, chromium, boron and other materials, which were not satisfactory. It was not until the vacuum valve was invented that the vacuum environment was created. Edison tried carbon wire and platinum wire again, and found that platinum wire has the characteristics of high temperature resistance in vacuum. After continuous research, Edison successfully developed a 25-watt platinum vacuum bulb in 1879. This achievement was patented in April 1879. However, due to the high price of platinum, the manufacturing cost of this kind of light bulb is high, which is not conducive to popularization. So Edison returned to the study of carbon wires.

Making a conductive core with huge resistance is the first condition to weaken the current, but it is not a simple matter to make a conductive core with carbon. Edison racked his brains for this, but there was no good way. But one day, he saw a thread fall to the ground and suddenly realized. Edison cut nylon thread into a certain length, coated it with coal tar and carbon powder, and then baked it in a horseshoe mold made of nickel. As expected, fine carbon wire was made. Later, Edison spent two days bending the carbon wire, putting it in a glass bulb and carefully pumping out the air inside.

1879 65438+1February 2 1, this is an extremely solemn and tense day. Everyone held their breath and watched Edison connect the wires with trembling hands and close the switch. The light snapped on and cheers rang out from the college. It was this day-the long-awaited electric light began to illuminate people's lives. The lights went out for 45 hours, which woke them up like a dream.

Edison proudly walked into the patent office with the light bulb he invented early. This constantly invented light source has changed people's way of life and work. The key to Edison's success lies in finding a filament that can shine in a light bulb without being completely burned out.

The news that Edison invented the electric light shocked the world and brought joy to the world. Anyone who spends a night without electricity will deeply appreciate this joy. But Edison did not stop, and continued to work on the improvement of electric lights. In order to develop a more durable wick, Edison tried thousands of plant fibers and changed various processing methods such as baking, burning and compression, but it still had no effect.

The god of inspiration always comes so coincidentally. One day this summer, Edison was working hard in the laboratory. He was so hot that he sweated, so he picked up a bamboo fan to cool himself down. Suddenly, he stared at Fan. After a while, he tore the fan into pieces and observed it carefully under the microscope. Looking at it, I couldn't help jumping up and saying, "Hi! Why didn't I think of using carbonized bamboo wire? "

So he jumped up at once, extracted fiber from bamboo strips and baked it into a strong wick. Edison sealed the wick made of bamboo wire into the light bulb, pumped air and electrified it. The luminosity is brighter than the first light bulb, and the service life has been extended for several days.

In this success again and again, Edison gained strength. In order to find a more durable wick, he tried almost all kinds of bamboo. By 1880, the life of carbonized bamboo filament incandescent bulbs exceeded 600 hours for the first time.

"This is satisfaction!" The assistants also said happily.

After that, Edison continued his research to improve the quality of electric lights. Later, he changed the bamboo light bulb into tungsten light bulb, which is the light bulb we use now. For this small light bulb, Edison spent 12 years, conducted thousands of experiments and devoted a lot of effort.

Edison's invention of electric light went through a tortuous process. The life of the first bulb is extremely short, mainly because the filament is easy to burn out. The temperature of the filament is as high as 2300℃ ~ 3000℃, and general metals will melt at this temperature. After many experiments, the metal tungsten with the highest melting point was finally selected to make the filament. The melting point of tungsten is 3465438 00℃. Although the melting point of tungsten is very high, it still can't make the bulb durable, because tungsten metal can easily react with oxygen at high temperature. After oxidation, tungsten becomes tungsten trioxide.

Later, people pumped the air out of the bulb, so that the bulb was in a vacuum state, the tungsten wire was not oxidized, and the life of the bulb was prolonged.

After the news of Edison's invention of electric light spread all over the world, countries demanded to use this achievement one after another. But at that time, there was no power device, so we had to rely on voltaic batteries for power supply. Each voltaic battery is as big as a pillow, and it needs 100 batteries to light the lamp, so the electricity used to power the lamp can't come from such a huge power supply, and ordinary families can't use it.

Edison saw the necessity of inventing the generator and thought it necessary to develop a method to transmit electricity. So the research institute for developing light bulbs became the electric power research institute. Edison ordered steam equipment with excellent performance, improved the generator and established the world's first central power station in new york in 1882. This power station has Edison's further improved power generation equipment and transmission equipment. The electricity generated by this generator can power 800 lamps nearby through wires. One year later, the power supply increased to 1700. Great changes have taken place in human life since then.

In the history of electricity, Edison's contribution is not just electric light. 1880 In this year, Edison obtained 32 patents for electric lamps, 7 patents for power distribution, 5 patents for electric lamp parts such as lamp holders and 3 patents for generators, which shows his great contribution.

6. Edison era

After the invention of the electric light, Edison continued his career of invention. Trams, cameras, batteries, telecommunications machines, his invention patents reached 1300. None of these inventions are weapons or gunpowder. This is the best proof that Edison loves human happiness and peace. "Inventing for the happy life of mankind" is Edison's lifelong belief. Edison's notes show that although he was not trained, he knew many scientific principles. He has a very scientific research method, which is worth learning. Edison is not only an "old school" inventor who likes to spend a lot of time working in the laboratory, but also a modern businessman. He can set up a professional working group and put his profits into research work. When he was born, the world was still in the "dark age"; When he died, the world had entered the era of mechanical technology and electronics. On the occasion of Edison's 80th birthday, 1929 On May 30th, President Hoover of the United States held a celebration for the 50th anniversary of Edison's electric light invention. Two years later, 193 1 year1October 2 1 day, the great inventor finished his glorious life. On this day, the whole country pays tribute to "Menlo Park Magician". People turn off all the lights and appliances for a minute, and the whole United States is in darkness. History will always remember the great Edison era.