How do I choose a car LED headlight?

1. Brightness (lumen)
The lumen value is closely related to the brightness. Usually, the larger the lumen value, the brighter the lamp. Many bad businesses will advocate high lumen value. They have asked to prove that the product is very bright, but in fact, they do not test and calculate the lumen value in the correct way. Generally, large regular manufacturers will use the integrating sphere to comprehensively calculate the convective value. Integrating sphere is a hollow sphere with white diffuse reflective material coated on its inner wall, also known as photometric sphere, luminous flux sphere, etc. it is a professional and high-efficiency device used to collect the light scattering or emission of the sample in or outside the sphere and close to a window.
Lumen value is a test result and is affected by many factors., The magnitude of current, the thickness of lampshade and the calculation algorithm will lead to great differences in lumen values. Therefore, it is incorrect to judge whether the lamp is bright and whether the performance is excellent only by the lumen value measured at a single and brightest point.
2. Color temperature (Kelvin)
As for the color temperature, the larger the value, the better. Color temperature is a unit of measurement that indicates the color component contained in light. The natural light source in the daytime belongs to a higher color temperature. The human brain will be more energetic under high color temperature lighting, and the human eyes will feel more comfortable. Therefore, this is also the reason why the closer the color temperature of the lamp is to the natural light in the daytime, the better.
The above two pictures can clearly feel the difference caused by different color temperatures on the feeling of the eyes, and the color temperature 6000K is the most comfortable value relative to the eyes. Generally, the color temperature of lamps produced by major manufacturers of mainstream light sources on the market can reach 6000K. 6000K is the natural sunlight color temperature between the hot sun and cloudy sky, which makes people's eyes very comfortable. If the color temperature is higher than 6000K, the light color will be blue. Driving under the lights with too high color temperature for a long time will also cause obvious discomfort to human eyes.
3. Light type
The light type of automobile headlamp refers to the angle and shape of automobile headlamp light. A good light type has two important positive effects on the lamp. One is a clear light type light and dark cut-off line, which is a necessary guarantee for safe driving. It is not a high beam dog. If there is no clear cut-off line, the light type is not only scattered and does not focus, but more seriously, it makes the driver of the opposite car feel dazzling and shake his eyes when meeting, which affects driving safety.
Second, a good light type is more beneficial to the distance of paving, can illuminate a wider front road, the driver will have a wider left and right vision, and can timely find people or animals suddenly appearing from both sides of the vehicle at night. On the basis of meeting the clear cut-off line, make the distance between 50m and 75m in front of the vehicle bright and clear as far as possible, which can help the driver find obstacles earlier. The longer and wider the beam closer to the front of the vehicle, and the wider the irradiation range, the better.
4. Safety and service life
The first criterion for choosing any product should be safety! The second is the service life. For LED lamps, the heat dissipation directly affects its safety and service life.
There are two kinds of LED headlamp heat dissipation on the market, one is fan heat dissipation, and the other is heat dissipation belt heat dissipation. Relatively speaking, the active heat dissipation effect of fan is better. Active heat dissipation is better than passive heat dissipation, with higher heat dissipation efficiency, so as to increase the service life of the lamp. The heat dissipation principle of the LED lamp designed by the heat dissipation belt belongs to passive heat dissipation, which is achieved only through structural materials. It is easy to age, break and fall off under long-term high temperature. In addition, when the lamp is installed, due to the design of the lamp, the installation space is very limited, the heat dissipation belt is difficult to fully expand, and the heat dissipation effect is poor. The laptop is the fan used to actively fan heat. When the workload is too heavy, your laptop must be blowing all the time.