How to buy student desk lamps

I was deeply poisoned by garbage lamps, and I decided to write a note when I chose a better lamp. This article is based on the author's experience, please indicate if there is an error.

1. High brightness is not important

I have seen some LED energy-saving lamps business to promote the brightness of their own lights, in fact, at night, when the surrounding darkness, high brightness is useless. The human eye adjusts the aperture according to the average brightness of the environment, so the same brightness is more glaring at night than during the day. Multi-level brightness adjustment is a good choice. Of course, the brightness is too low and not good. It is better to see clearly than to see it.

2. Long battery life is not important

In general, 4-5 hours of battery life has been able to meet the daily needs. It is important to pay attention to the battery type here. Generally, the lead-acid battery will have a severe performance degradation when it is used for less than half a year. It is difficult to replace it and the battery is expensive. Lithium batteries have a relatively good effect, but they are more expensive. The quality of the power supply module is also very important. A good power supply module can extend the normal battery life. Say a simple way to judge the quality of the power supply module: If the brightness of the light bulb is slowly reduced (especially LED lights) when the power is exhausted, the quality of the power supply module must not be good.

3. The area of ​​illumination is a little better.

As mentioned before, the human eye controls the amount of light entering according to the average brightness of the environment. Therefore, if there is a small piece of light in the darkness, the eyes will be very uncomfortable. Therefore, please choose a table lamp with a relatively scattered light and a large bulb area. Of course, it is recommended not to use a lamp that leaks light upwards, which affects roommates.

4. Choose a relatively safe power supply

In general, desk lamps are powered in two ways: 220V AC direct access or low voltage DC access, which is relatively safe. Especially for the products of small factories, the quality is generally not high. Once the wires of 220V AC access are damaged, the consequences are unimaginable. Some time ago, there was such a desk lamp in front of me that the power supply line was short-circuited. Fortunately, I was not hurt, and I was worried. If it is a 5V DC input, it can also be charged using the USB interface or mobile power supply, which is more convenient to use. Of course, it is still necessary to check regularly if the wires are damaged and the connectors are loose. If abnormalities such as overheating, odor, and charger indicator are off during charging, stop charging immediately.

5. Color temperature is very important

Maybe many people don't know what color temperature is. Very inaccurately speaking, the color temperature is the ratio of the red and blue lines. Studies have shown that one type of cells in the human eye is very sensitive to blue-violet light, and the color temperature is too high (more blue-violet light) not only affects the quality of sleep, but also has a serious impact on human endocrine and circadian clocks. Generally, the lamp of the lamp tube is used, and there is a color temperature mark on the lamp tube, which is preferably less than 5500K. The color temperature of LED luminaires is generally higher than 6500K (daylight), so it is not recommended to use it for a long time at night. (As far as I am concerned, the color temperature of the desk lamp I use is 5000K, and the color temperature of the computer screen at night is 2700K.)

6. The appearance is not important

If I say this, someone will say that I am going to be alone. However, I still want to emphasize that the appearance is for the function, and it is useless to have no function. So, finally consider the appearance.