However, the light generated by this lamp is too strong, so it can only be installed in streets or squares, and ordinary families can't use it.
Numerous scientists have racked their brains to make a cheap and durable household electric light.
The light bulb was invented by Henry Goebbels in 1854. Henry Goebbels is a German watchmaker who immigrated to America. He is also a member of the list of tragic inventors because these people don't know how to make their inventions public.
Comrade Edison is completely different. About 20 years after Henry Goebbels, he invented a similar light bulb. Swan, who made the light bulb in 1860 and perfected it in 1878, at least later became Edison's business partner. On the contrary, Henri Goebbels did not obtain legal rights until the eve of his death.
1879 10 2 1 American inventor Edison finally lit the world's first electric lamp with practical value after long-term repeated experiments.
The lamp is a great witness of human conquest of the night.
Since then, the inventor's name, like the electric light he transformed, has entered thousands of households.
He is Edison, known as the "king of invention" by later generations, and has brought lasting light to mankind.
1847 In February, Edison was born in Milan, Ohio, USA.
He is the child of a railway worker. He dropped out of school before finishing primary school and made a living by selling newspapers on the train.
Its invention has created many achievements 1000, such as electric light, phonograph and movie camera, and made great contributions to mankind.
When Edison 12 years old, he was addicted to scientific experiments. After his tireless self-study and experiments, at the age of 16, he invented an automatic telegraph that sends signals every hour.
Later, the automatic counting machine, the first practical typewriter, double and quadruple telegrams, automatic telephones and phonographs were invented one after another.
Edison was not satisfied with these inventions.
He is particularly interested in electrical appliances. Ever since Faraday invented the electric motor, Edison was determined to make electric lights and bring light to mankind.
1in September, 878, Edison decided to attack the fortress of electric lighting.
He read a lot of books about electric lighting and made up his mind to make cheap, durable, safe and convenient electric lights.
Edison made a detailed test plan after carefully summarizing the previous failure experience in manufacturing electric lamps, which was divided into two aspects: one was to classify and test 1600 different heat-resistant materials; The second is to improve the vacuum pumping equipment to make the bulb have a high vacuum degree.
He also studied the new generator and circuit shunt system.
He started the experiment with an incandescent lamp.
Put a small piece of heat-resistant thing in a glass bubble, and when the current burns it to a white-hot level, it will give off heat and glow.
His first thought was charcoal, so he put a small piece of charcoal wire into a glass bubble, and the glass bubble broke as soon as it was electrified.
Edison picked up the carbon wire broken in two and looked at the glass bubble again. After a long time, he suddenly remembered: "Oh, maybe it's because there is air in it. The oxygen in the air helps the carbon wire burn and makes it break immediately!" " So he used his own hand-made air extractor to extract the air from the glass bubble as much as possible.
Once it is electrified, it will not go out immediately.
But eight minutes later, the light went out.
Edison finally found that the vacuum state is very important for incandescent lamps, and the key is carbon filament, which is the key to the problem.
Edison thought about it. Platinum has the highest melting point and strong heat resistance! So Edison and his assistants tried platinum several times, but this kind of platinum with higher melting point prolonged the luminous time of the electric lamp a lot, but it was still not ideal to turn it off automatically and then glow from time to time.
Undaunted, Edison continued his experimental work.
He tried various rare metals such as barium, titanium and indium, and the results were not very satisfactory.
After a while, Edison made a summary of the previous experimental work and wrote down all kinds of heat-resistant materials he could think of, totaling 1600.
Next, he and his assistants began to test 1600 kinds of heat-resistant materials in different categories. You can try it, and platinum is the most suitable one.
Due to the improved air extraction method, the vacuum degree in the glass bulb is higher and the life of the lamp is extended to 2 hours.
But this kind of platinum lamp is too expensive. Who wants to spend so much money on a light that can only last for two hours?
The experimental work fell into a trough, and Edison was very upset. In a cold winter, Edison sat by the fire and looked at the burning coals. He couldn't help saying to himself, "Charcoal, Charcoal …"
"Can be made of charcoal charcoal has been tried, what should I do? Edison felt hot all over, so he pulled down the scarf around his neck. Seeing this scarf made of cotton yarn, Edison suddenly had an idea in his mind: Yes! Cotton yarn has better fibers than wood. Can you use this material? He quickly tore off a cotton yarn from his scarf and baked it on the fire for a long time. Cotton yarn turned into charred charcoal.
He carefully put this carbon wire into the glass bubble, and after testing, the effect is really good.
Edison was very happy, and then he made a lot of carbon filaments from cotton yarn and did many experiments in succession.
The life of the light bulb reached 13 hours, which was suddenly extended to 45 hours.
Everyone congratulated Edison, but Edison didn't look happy at all. He shook his head and said, "No, we have to find other materials!" " ""What, you haven't worked for 45 hours? " The assistant asked in surprise.
"no! I hope to open 1000 hours, preferably 16000 hours! " Edison replied.
As we all know, it is good to shine for more than 1000 hours, but what materials can we find? Edison knew what he was doing.
According to the nature of cotton yarn, he decided to look for new materials from plant fibers.
So, the marathon experiment began again.
Edison experimented with all kinds of plant materials he could find, even horse mane, human hair and beard were used for filament experiments.
Finally, Edison chose bamboo as a plant.
Before the experiment, he took out a bamboo and observed it with a microscope. He jumped for joy.
So, put the carbonized bamboo filament into the glass bulb, and after electrifying, the bamboo filament bulb lights continuously 1200 hours! Edison finally breathed a sigh of relief, and his assistants congratulated him one after another, but he said seriously, "There are many bamboos in the world, and their structures are different. We should choose them carefully! "
Edison's scientific attitude of pursuing perfection deeply touched him, and his assistants volunteered to visit various places.
After comparison, a kind of bamboo produced in Japan is the most suitable, so it is imported from Japan in large quantities.
At the same time, Edison started a power plant and set up electric wires.
Soon, the American people used this cheap and durable bamboo light bulb.
Bamboo filament lamp has been used for many years.
Until 1906, Edison switched to tungsten wire, which improved the quality of the light bulb and has been used ever since.
Electric light is the most famous invention at the end of 19, and it is also Edison's most brilliant contribution to mankind.
People think highly of Edison: in Greek mythology, Prometheus stole skyfire from human beings; Edison brought light to mankind.
Edison later invented high-power generators, insulated wires and shunt circuits.
Edison made great contributions to the invention, popularization and application of electric light.