He started experimenting with incandescent lamps. Put a small piece of heat-resistant material in a glass bubble, and when the current burns it to a white-hot level, it will heat and glow. The first thing he thought of was charcoal, so he put a small piece of charcoal wire into a glass bubble. The glass bubble burst when electricity was applied.
"What's the reason?" Edison picked up the carbon filament that was broken into two pieces and looked at the glass bubble again. After a while, he suddenly remembered: "Oh, maybe it's because there is air inside. The oxygen in the air helps the carbon filament burn and cause it to break immediately!" So he used the air extractor he made by himself to remove the carbon filament. Take out as much air as possible from the glass bubble. Once it's powered on, it won't go out right away. But eight minutes later, the lights went out.
In any case, Edison finally discovered that the vacuum state is very important for incandescent lamps, and the key is the carbon filament, which is the key to the problem.
So what kind of heat-resistant material should be chosen?
Edison thought about it and realized that platinum has the highest melting point and strong heat resistance! So Edison and his assistants tried platinum several times, but this platinum with a higher melting point made the lamp glow much longer, but it was still not ideal to automatically turn off and then light up from time to time.
Edison was not discouraged and continued his experimental work. He tried various rare metals such as barium, titanium, and indium, but the results were not very satisfactory.
After a while, Edison made a summary of his previous experimental work and wrote down all the various heat-resistant materials he could think of, a total of 1,600 types.
Next, he and his assistants began to test 1,600 heat-resistant materials in different categories. They could try it. Platinum is the most suitable one. Due to improved extraction methods, the vacuum inside the glass bulb is higher and the lamp life is extended to 2 hours. But this platinum lamp is too expensive. Who wants to spend that much money on a light that only lasts two hours?
The experimental work fell into a trough, and Edison was very distressed. On a cold winter day, Edison sat by the stove and looked at the burning coals. He couldn't help but say to himself, "Charcoal..."
The charcoal bars have been tried. what do I do? Edison felt hot and dry all over, so he pulled off the scarf around his neck. When Edison saw this scarf made of cotton yarn, he suddenly had an idea in his mind:
Yes! The fiber of cotton yarn is better than that of wood. Can you use this material?
He quickly pulled off a piece of cotton yarn from the scarf and roasted it on the fire for a long time. The cotton yarn turned to burnt charcoal. He carefully put the carbon filament into the glass bubble. After testing, the effect was indeed good.
Edison was very happy, and then he made a lot of carbon filaments from cotton yarn and did many experiments in succession. Lamp life was extended by 13 hours and later reached 45 hours.
As soon as the news spread, it caused a sensation all over the world. British London Gas shares plummeted, and the gas industry was in chaos. People have a premonition that lighting gas lamps will soon become a thing of the past, and the future will be the age of electric light.
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, it has been useless for 45 hours? the assistant asked in surprise. "No!" I hope it can be driven for 1,000 hours, preferably 16,000 hours! "Edison replied.
As we all know, it is good to glow for more than 1000 hours, but what materials can we find?
Edison knew what he was doing. According to the properties of cotton yarn, he Deciding to look for new materials from plant fibers, Edison experimented with all kinds of plant materials he could find, and even horse hair, human hair and beards were used. Filament experiment. Finally, Edison chose bamboo as the plant. Before the experiment, he took out a piece of bamboo and observed it with a microscope. He jumped with joy.
So, carbonized bamboo filaments were put into a glass bulb. After being powered on, the bamboo filament bulb lit up continuously for 1,200 hours!
Edison finally breathed a sigh of relief. His assistants congratulated him, but he said seriously: "There are many bamboos in the world, and their structures are different. We should select them carefully!"
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Edison was deeply moved by his scientific attitude towards perfection, and his assistants volunteered to visit various places. After comparison, a type of bamboo produced in Japan was most suitable, so it was imported in large quantities from Japan. At the same time, Edison opened a power plant and laid out electrical wires. Soon, people in the United States had access to this cheap and durable bamboo light bulb.
Bamboo filament lamps have been used for many years. It wasn't until 1906 that Edison switched to tungsten filament, which improved the quality of light bulbs and is still in use today.
When people turn on the lights, they often think of this great inventor, who brought endless light to the darkness. From 65438 to 0979, the United States spent millions of dollars on a year-long commemorative event to commemorate the 100th anniversary of Edison's invention of the electric light.