Car lighting

Classification of car lighting:
1. Headlight: The main purpose of the headlight is to illuminate the road and objects in front of the car to ensure driving safety. Alternate high beam and low beam can also be used as a signal for overtaking at night. The headlamps are installed on both sides of the head of the car, with 2 or 4 in each car. The bulb power is 45~60W for high beam and 25~55W for low beam.
2. Fog lamp: The fog lamp is installed near the headlamp or slightly lower than the headlamp. It is a light fixture that serves as road lighting and provides signals for oncoming vehicles under conditions of low visibility such as fog, snow, heavy rain or dust. The light is mostly yellow, because the yellow light wave is longer and has good fog penetration performance. The bulb power is generally 35W.
3. Reversing light: The reversing light is installed at the rear of the car to illuminate the road behind the car and inform the vehicle and pedestrians that the vehicle is reversing or preparing to reverse. It also has the function of a light signal device. The light is white and the power is 28W.
4. License plate lamp: The license plate lamp is installed above the license plate at the rear of the car, and its purpose is to illuminate the rear license plate of the vehicle. The requirement is to be able to see the number on the license plate 20m behind the car at night. The light is white, and the power is generally 8~10W.
5. Top light: a light fixture installed on the top of the cab or inside the car for lighting in the cab. The ceiling light is white, the lampshade is mostly made of transparent plastic, and the bulb power is generally 5~8W.
6. Instrument light: It is a tool for instrument lighting and is often connected with the instrument panel. The light is white, and the bulb power is generally 2~8w.
7. Step light: It is a lamp used to illuminate the door step, which is convenient for passengers to get on and off. The light is white, and the bulb power is generally 5~8W.
8. Trunk light: it is the light in the trunk of a car. The light is white and the power is 5~8w.
9. Tool lamp: It is used when repairing cars. A working lamp socket is installed on the car, and it is equipped with a mobile lamp with a wire. The light is white, and the bulb power is generally 8-20W.
Lighting lamps should provide good lighting and minimize glare. For the headlamp, in order to take into account the above two requirements, two working conditions of high beam and low beam are adopted. The high beam is a long-distance illuminating beam used when there is no car ahead or following other cars. It is produced by the main filament with higher power at the focal point of the reflector, and the direction of the beam is approximately horizontal. It is usually stipulated that the maximum luminous intensity of a single lamp should not be less than 20,000 candela. In order to ensure driving safety, the illumination distance of the high beam (the distance to find and identify obstacles) should be greater than the braking distance to achieve timely parking. Given that the required high beam luminous intensity is approximately proportional to the 4th power of speed, most countries implement speed limits. In addition, in order to prevent the driver from losing recognition for a short time due to the disparity of light and dark changes when the working conditions of the far and near beams are changed, it is stipulated that the total maximum luminous intensity of the high beams of all headlamps shall not exceed 225,000 candela. The low beam is a short-distance illuminating beam used when rendezvous or trailing other cars. It is produced by a less powerful secondary filament. The beam is projected downward due to deviation from the focus and optical axis of the reflector. In order to limit the beam above the horizontal direction, a metal light shield is usually installed under the secondary filament, so that a light shape with sharp changes in brightness and darkness is formed on the vertical screen. When the car is crossing, the eyes of the driver of the oncoming car are in the dark area of the low beam light shape. Inside, which minimizes glare.