What is the development process of lamps?

The development history of the lantern

The bold imagination of a physics professor In 1802, at the Petersburg Medical College of Surgery in Russia, a physics professor named Petrov announced, He intended to "make light out of electricity." In the early 19th century when bonfires, pine trees, animal and vegetable oils and gas were still the main lighting methods, and when electricity was still a new thing, this decision was tantamount to a night in the sky. But Petrov's enthusiasm was not extinguished by everyone's cynicism, because not long ago, he was inspired by the American physicist Franklin's method of flying a kite to induce sparks: when the two ends of the battery pack are connected by wires, Can the generated sparks be turned into long-lasting light for lighting purposes? In order to achieve the desired effect, Petrov made unremitting efforts. Although he never saw a "lasting light" before his death, Petrov discovered the "electric arc" - "If two carbon rods are brought close to each other, a very bright white light will appear between them. or white flame, which caused the charcoal rod to burn quickly or slowly, and could completely illuminate a dark large room." This is the earliest statement about electric lighting. The discovery of the electric arc marked a decisive step in the transformation of electricity into light.

From arc lamp to incandescent lamp

At about the same time, the famous British chemist David, who was immersed in electrochemical research in 1809, also discovered the electric arc. He made a large electrical storage device with his own hands and used 2,000 voltaic cells to obtain a stronger and brighter arc.

The experimental devices of Petrov and David are relatively similar. This is actually the prototype of a new type of lamp - the carbon arc lamp. At that time, this kind of lamp used charcoal rods made of ordinary charcoal, which burned out too quickly, and the dazzling arc light seemed to be short-lived.

About 30 years later, someone thought of and applied hard and dense coke to replace ordinary charcoal. Since coke burns slower than charcoal, the arc flash time is much longer.

Later, French technicians installed a clock device on the arc device so that it could automatically adjust the distance between the two carbon rods. In this way, the first carbon arc lamp was officially born.

In 1876, the Russian electrician Yablochikov carried out major reforms in the arc lamp. He eliminated the complicated clock mechanism and magnet lamp adjustment device, and instead stood two carbon rods side by side, separated by an insulating sheet made of clay or plaster. He also used a device that could continuously change the direction of the current so that two carbon rods alternately act as anode and cathode. In this way, the burning rate of the two carbon rods is basically the same, and the distance between their ends can be Remains unchanged. Because the two carbon rods standing side by side looked like candles when they glowed, people gave it a nice name "electric candle". The electric candle emits a beautiful light red or lavender light, and each candle can last for about two hours.

In the latter years of the 1870s, electric candles were all the rage. Electric candles invested and manufactured by the French General Electric Association were once used as street lamps and lit one by one on the streets. In Paris alone, thousands of electric candles were used to replace the original 70,000 kerosene lamps on the streets. The bustling Paris has become a veritable city that never sleeps. Electric candles also illuminated the streets of London, England and ancient Persia, and also shimmered over the Roman Theater and the Royal Palace of Cambodia...

The advent of arc lamps opened up a new era of electric lighting, which was a significant step in the history of human lighting. It has great prophetic significance. Due to its strong luminosity, high luminous efficiency and good color rendering, arc lamps have incomparable advantages in printing and plate making, film projection and other fields, and they still occupy a place today. However, electric candles consume a lot of power, have a short lifespan, and produce harmful gases. Therefore, after the emergence of incandescent lamps, they almost disappeared in the lighting field.

In 1879, Edison built the world's first practical carbon filament incandescent lamps based on the research and practice of his predecessors. Edison used an improved carbonization method, sprinkled a length of cotton thread with charcoal powder, bent it into a horseshoe shape, put it in a clay crucible and heated it at high temperature to make a filament. Then he sealed the filament into a glass bulb and carefully extracted the air inside. On October 21 of that year, the lightbulb began to light up and continued to glow for 45 hours! Edison made a huge contribution in the creation of the incandescent lamp.

From immaturity to maturity

The brilliance of incandescent lamps is deeply rooted in the hearts of the people, and a large number of inventors have devoted themselves to the improvement of incandescent lamps. In fact, before the birth of carbon filament incandescent lamps, people tried to use various refractory metals to make filaments. After the advent of incandescent lamps, people spared no effort in seeking ideal filaments. Finally, in the 9th year of the 20th century, American Curry found a filament material with excellent performance - tungsten. Tungsten has many remarkable characteristics. It has a higher melting point than any other metal element, and it evaporates less when heated. Therefore, tungsten is the most suitable material for use as a filament. Using tungsten filament as a filament to make incandescent lamps is a milestone in the history of lighting technology. The introduction of tungsten wire has enabled incandescent lamps to achieve a decisive victory in the competition with kerosene lamps, gas lamps, and gasoline lamps; the application of tungsten wire has effectively promoted the development of the electrical lighting industry and opened up a new era of electrical lighting technology.

The improvement of incandescent lamps has not rested on its laurels.

In 1913, Lanmire filled the glass bulb with nitrogen for the first time. This was another important innovation in incandescent lamps after the filament was changed from carbon filament to tungsten filament. The glass bulb is filled with nitrogen, and a thin and stable gas protective layer is formed around the filament, allowing the filament to work at a higher temperature, effectively inhibiting the evaporation of the tungsten filament, and overcoming the performance problems of the tungsten filament during use. Defects (to this day, inflation is still an important step in the light bulb manufacturing process).

After that, in order to improve the luminous efficiency of incandescent lamps and extend the service life of the bulbs, people once again worked hard on the composition and structure of the filament. Inventors introduced a new element - rhenium. The advantage of rhenium is that it not only has a high melting point and is corrosion-resistant, but also has good mechanical properties and a much higher resistivity than tungsten. After the tungsten wire is coated with rhenium, the strength and resistance are greatly enhanced, and the life span can be extended by 5 times! At the same time, people began to make the filament into a spiral shape. On the one hand, this can reduce the space occupied and improve the luminous efficiency. On the other hand, it can continue to reduce the evaporation of tungsten and extend the service life. It can be said that it kills two birds with one stone. In 1936, people made a double-spiral filament, which increased the operating temperature of gas-filled incandescent lamps to more than 2500°, and incandescent lamps for photography even reached 3000°: the first generation of incandescent lamps matured.

Throughout the 20th century and into the 21st century, incandescent lamps have always been a beautiful scenery in the large family of lighting appliances. Although fluorescent lamps, fluorescent lamps, and neon lamps that are better than incandescent lamps have appeared in today's life, ordinary incandescent lamps still play an irreplaceable role in ordinary people's home lives.