The Columbia No. 1 electric vehicle used the front lights and taillights to turn on the history of the car lights in 1898. It has been developing for more than 100 years. The car lights have formed a complete system, in addition to the basic lighting and signal indication. In addition, with the progress of technology, car lights have formed the halogen, xenon, LED pattern, below to introduce the characteristics of their respective lighting and maintenance skills.
Car headlights mainly include halogen, xenon and LED, in which the middle and low end cars mainly use halogen lamps, and the xenon headlights are common in some middle and high end vehicles, while the LED headlights are only used on a very small number of new vehicles.
Halogen lamps are in fact a special type of incandescent lamp. The principle is that the resistance is heated when the current passes through. When the temperature is high enough, the black body radiation of the wavelength in the visible band is emitted. There are two kinds of halogen lamps: the iodine tungsten lamp and the bromine tungsten lamp. When the incandescent lamp is lit, the temperature of the filament does not exceed the melting point and the boiling point of tungsten, but a small amount of tungsten will evaporate at high temperature. When the volatile tungsten atoms encounter the colder bulb shell, they will coagulate and precipitate. Over time, the shell of the bulb will accumulate a layer of dark tungsten film. This is why ordinary incandescent lamps are black for a long time.
If some iodine is filled in the bulb, when the bulb is lit up, iodine will evaporate into gas, and the iodine vapor meets the cold tungsten, and it will react to produce a compound &mdash of low boiling point; — tungsten iodide, which will volatilize the tungsten in the shell of the bulb. Tungsten iodide gas will decompose in high temperature. When the tungsten gas meets the filament, it breaks down and leaves the tungsten on the filament, and the iodine continues to dissociate between the filament and the shell in the form of gas. When it comes to the shell of the bulb again, it will react with the tungsten on the shell. In this way, the filament does not stop to volatilize the tungsten on the shell of the lamp. On the other hand, the iodine does not stop. The tungsten is transported back to the filament, so that the consumption of the filament is greatly reduced, and the life of the lamp is prolonged. So we can use the iodide lamp to make a great power incandescent lamp. If it does not add halogen, the ordinary incandescent lamp will be very short and difficult to use if it does so much power. Halogen lamps have been widely used in the field of automobile lighting.
The full name of the xenon lamp is the HID (High Intensity Discharge Lamp) gas discharge lamp. It uses a matching electronic ballast to lift the 12V voltage of the car battery to the trigger voltage above 23KV instantaneously. The xenon gas in the xenon lamp is ionized to form an arc discharge to make it light stable and provide a stable lighting system for automobile headlights. Compared with ordinary halogen bulbs, xenon bulbs have two significant advantages: on the one hand, xenon bulbs have three times more light intensity than ordinary halogen bulbs, and energy consumption is only two per cent; on the other hand, xenon bulbs use the same light as sunlight, creating better visual conditions for drivers. Xenon lamps make the illumination range wider and the illumination intensity greater, which greatly improves the safety and comfort of driving.
Halogen lamps have the same filament as ordinary bulbs, but xenon lamps have no filament. This is the most important difference between xenon lamps and traditional lamps. Xenon lamps emit light from the arc generated by the two electrode discharge devices, just like the bright light generated by electric arc welding. The high pressure pulse is added between the metal electrodes in a completely closed miniature quartz bulb, which excite the material (xenon, a small amount of mercury vapor, and metal halide) to ionize the light in the arc.
This bright color temperature is similar to that of the sun, but contains much more green and blue components, thus showing blue and white light. The blue and white light increases the brightness of road signs and signboards. Xenon light emitted more than 2 times the halogen lamp, and the efficiency of electric energy conversion to light energy was more than 70% higher than halogen lamp, so the xenon lamp had higher energy density and light intensity, and the running current was only half of the halogen lamp. The improvement of the brightness of the car lights also effectively expands the visual range in front of the car, thus creating safer driving conditions.
LED is the abbreviation of Light Emitting Diode, commonly known as light emitting diodes. They are often used as light boxes, signs and the role of the indicator and backlight of various electrical appliances. It is also an important component of car headlights, taillights, high brake lights, and daytime traffic lights. Compared with xenon lamp, halogen lamp, LED has higher luminous efficiency, energy consumption is only 1/20 of halogen lamp, and the cost of LED element has also been greatly reduced year by year, and the current cost and price are still falling by more than 20% per year.
In addition to energy saving and low cost, the LED lamp has a long life span, and the life span of LED is 100000 hours long. The design life of the whole vehicle does not need to be replaced. In addition, because of its special structure, LED has a very good shock resistance, very good earthquake resistance, and is not easy to break, and can be well adapted to various environments. The LED element is also compact, compact, easy to layout and styling.
The LED's light only needs a microsecond level. It is used on the taillight and turn light to quickly light up the warning effect. It is used on the front headlights, with a higher response speed than the xenon lamp and the halogen lamp, and is better guaranteed for the safety of the traffic. LED has high brightness and light brightness attenuation far below halogen lamp. It is suitable for warning lights such as lighting and brake lights, turning lights, etc. Low voltage direct current can drive, load is small, interference is weak, to use ring.