Development history of car lights
Kerosene lamp (1886- 1904): When the car was first born, it had no function at all, let alone a light. It is said that in 1886, a driver got lost in the dark wilderness, and a civilian portable lamp took him home. This is also called the earliest thing for interior lighting. However, the luminous intensity of kerosene lamp is too low to meet the requirements of illuminating the front of the car and long distance. Therefore, in order to promote the lighting of the road ahead, people choose to place a Crupin reflector behind the kerosene lamp, making it the first spotlight in the world, which is also the earliest prototype of this lamp.
Acetylene lamp (1905- 1925): However, kerosene lamps were quickly replaced by acetylene lamps because of their low luminous power. Some people may ask that the incandescent lamp was invented as early as 1879. Why are acetylene lamps first used in cars? This is because the filament of vacuum incandescent bulb was carbon filament at that time, and the filament that was too soft could not withstand the fluctuation on the road and could not be used in headlights. And at that time, the brightness of acetylene lamp was almost twice that of electric lamp, so acetylene lamp became the first choice of lamps at that time. There have been other high light sources since then, but they all failed for various reasons. After all, as long as the acetylene lamp becomes the stable light source of early headlights, it will always be used around 1925.
With the development of automobiles, the defects of acetylene lamps are gradually exposed: acetylene lamps glow by burning, and are simply doused by rain on the road, and driving in bad weather becomes a driver's nightmare. Secondly, acetylene lamps are not as durable as incandescent lamps. In addition, after acetylene is burned, it will produce a lot of sodium and calcium. This harmful substance, which can dissolve protein, will have strong irritation and corrosiveness when it falls on the skin, leading to serious adverse reactions such as shock and gastric perforation.
Incandescent lamp: With the development of electric lamp and the improvement of durability, acetylene lamp, together with its defects, gradually withdrew from the historical stage of lamp. On the contrary, incandescent lamps are becoming more and more complicated.
Halogen lamps: However, the luminous power of incandescent lamps is not high, so more energy-saving halogen lamps were born. The first halogen lamp for car lamps was born in the 1960s, and later the famous Haila was the manufacturer. In fact, halogen lamps are an upgraded version of incandescent lamps used in our lives. The use of halogen elements can improve the brightness of incandescent lamps by 1.5 times, and the service life of incandescent lamps is 2-3 times that of ordinary incandescent lamps. In order to improve the luminous power of incandescent lamp, the temperature of tungsten filament should be increased first, but the tungsten will increase accordingly and condense on the glass bulb, making it black. The blackening phenomenon of incandescent bulbs can be eliminated by filling halogen elements or halides in incandescent bulbs and using the principle of tungsten halogen cycle, which is the reason of halogen lamps.
Xenon headlights: In view of the disadvantages of incandescent lamps, such as low brightness, high power consumption and short life, Hailar, a professional lamp manufacturer, introduced exquisite xenon headlights to the market in the 1990s. Xenon lamp broke the luminous principle of tungsten wire invented by Edison. At the right time, high-voltage inert gas is filled into the lamp tube to replace the traditional filament, and xenon is excited to emit light with high-voltage current of 23,000 volts, forming a perfect white arc between the north and south poles. Xenon lamps have three times the brightness, half the energy consumption and seven times the service life of halogen lamps. Simply put, as long as there is no man-made damage, there is no need to replace the headlights within the service life of the vehicle for more than ten years. However, the xenon headlights used at first will cause glare to the opposite driver, which is a danger to safety. Later, the problem was solved by using active headlight height adjustment.
Headlights: After xenon headlights, there will be no ubiquitous LED headlights. Although it has been seen in many concept cars, due to the relationship between technology, cost and regulations, the loading of LED headlights has only begun in recent years.
Laser headlights: After LED headlights, laser headlights are called "the next logical step". The principle is that the blue light of the laser light-emitting diode will penetrate the fluorescent phosphorus material in the headlight unit and be converted into scattered white light. More energy-saving and fuel-saving summary: As an important automobile skill, the history of headlights is simply to synchronize with cars. Not only are all kinds of skills broken, but they are also closely related to automobile design. With the development of science and technology, the story of car lights will continue.
At present, there are three common headlight light sources: halogen, xenon and LED. What are their advantages and disadvantages?
Halogen headlamp
At present, halogen headlights are still the most common automobile light source. After thousands of experiments, Edison, the inventor of the king, finally made the tungsten wire glow after being electrified. Later generations improved and added halogen gas-iodine or bromine to the bulb, which is the halogen headlight we see now.
Its biggest advantages are simple structure, low manufacturing cost and mature technology. The brightness is also easy to control, and the penetration is relatively strong, and the penetration effect is excellent in extreme weather such as rain, snow and fog.
The disadvantages are also obvious, that is, limited irradiation distance, large heat, low efficiency and short service life. With the upgrading of cars, the number of cars using halogen light sources is decreasing year by year and will eventually be eliminated.
Xenon headlight
Xenon headlights are the most modified. The principle is that the inert gas-Xenon is filled in the ultraviolet-proof crystal glass tube, and then the vehicle-mounted 12 volt power supply is instantly raised to 23,000 volts through the supercharger. At high voltage, xenon will be ionized, and a light source will be generated between the two poles of the power supply.
Its advantage is that the brightness is much higher than that of halogen headlights, the price is not too expensive, and the modification is relatively easy.
The disadvantage is also very prominent, that is, it takes some time to achieve the lighting effect after opening, and the penetration effect is also very general in extreme weather such as rain, snow and fog. In addition, if xenon headlights are not used with lenses, it is easy to make the lights diverge and affect driving safety.
LED headlamp
LED headlights are now standard in some high-end cars. It is similar to an energy-saving lamp at home, and it is a light source generated by a power generation diode, which can directly convert electric energy into light energy without wasting. The same electric energy is more than three times that of halogen lamps, and it will not overheat, so it can be said that it is bright and saves electricity.
The advantages of this lamp are more energy-saving and environmental protection, low cost, long service life, high brightness, higher low-voltage safety and small size. Each bulb can be arranged into the required shape at will. For example, Audi's matrix headlights can reduce the lighting for pedestrians and vehicles, thus forming a kind of protection.
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