三莹品牌的电解电容的寿命有2000小时，5000小时，10000小时的。如果选用2000小时的电解电容，按照每天工作12小时来计算的话，那么它的使用时长是2000小时/12小时就是166天吗？很多人都会觉得就是这样计算的，其实非也。
The service life of the electrolytic capacitor of Sanying brand is 2000 hours, 5000 hours and 10000 hours. If the 2000 hour electrolytic capacitor is selected, and the working time is 12 hours per day, will it last 2000 hours/12 hours or 166 days? Many people think that this is the way to calculate, but it is not.
正确计算
三莹电解电容寿命的方法是要根据电解电容的工作环境来计算的。电解电容器的寿命主要受温度的影响。通常，温度每降低10°C 电解电容的预期寿命会增加一倍。因此，建议在低于规格书中保证的最高温度之内，以尽可能低的温度使用电解电容器。
The correct method for calculating the life of electrolytic capacitors is based on the working environment of electrolytic capacitors. The life of electrolytic capacitors is mainly affected by temperature. Generally, the expected life of the electrolytic capacitor will be doubled for every 10 ° C temperature reduction. Therefore, it is recommended to use electrolytic capacitors at the lowest possible temperature within the maximum temperature guaranteed in the specification.
因为如果工作温度超过规格书中最大的保证极限，电容器的电参数会下降，在最坏的情况下极有损坏的危险。因为电解电容是靠其内部的电解液来工作的，而电解液会不断蒸发变少，温度越高，蒸发越快，从而会大大减少电解电容的寿命。那么如何分析电解电容的温升呢？
Because if the working temperature exceeds the maximum guarantee limit in the specification, the electrical parameters of the capacitor will drop, which is extremely dangerous to damage in the worst case. Because the electrolytic capacitor works by its internal electrolyte, and the electrolyte will continuously evaporate less. The higher the temperature is, the faster the evaporation will be, which will greatly reduce the life of the electrolytic capacitor. How to analyze the temperature rise of electrolytic capacitor?
要计算电解电容的最高工作温度，必须考虑以下因素：
To calculate the maximum operating temperature of the electrolytic capacitor, the following factors must be considered:
环境温度
ambient temperature
电容器纹波电流引起的温升。这个值基本上取决于电容器的ESR，也就是其内部电阻，以及工作频率。
Temperature rise caused by ripple current of capacitor. This value basically depends on the ESR of the capacitor, that is, its internal resistance, and the operating frequency.
在同一电路板上，靠近电容器的其他电子组件（功率晶体管，稳压器，功率电阻器等）传导和辐射的热量。
Heat conducted and radiated by other electronic components (power transistors, voltage regulators, power resistors, etc.) close to capacitors on the same circuit board.
电解电容结构
Electrolytic capacitor structure
寿命计算
Life calculation
计算公式
Calculation formula
L 1：在温度T1时的保证寿命（以小时为单位），也就是电解电容规格书中给出的寿命值。
L 1: Guaranteed life at temperature T1 (in hours), which is the life value given in the electrolytic capacitor specification.
L 2：在温度T2下的预期寿命（以小时为单位）。
L 2: life expectancy at temperature T2 (in hours).
T 1：电解电容规格书中给出的最高工作温度。
T 1: The maximum operating temperature given in the electrolytic capacitor specification.
T 2：电解电容实际工作的最高工作温度。
T 2: The maximum working temperature of the electrolytic capacitor.
举个例子，例如某电解电容在最大温度为105℃时，寿命为2000小时。根据计算公式，如果电解电容实际工作的最大温度是40℃，可以计算出其工作寿命是2000*2^（105-40）/10=181019H。
For example, when the maximum temperature of an electrolytic capacitor is 105 ℃, the service life is 2000 hours. According to the calculation formula, if the actual maximum working temperature of the electrolytic capacitor is 40 ℃, its working life can be calculated as 2000 * 2 ^ (105-40)/10=181019H.
但是事实上我们一般是知道设计寿命，然后根据设计寿命计算温升，比如说如果产品的设计使用寿命为3年，也就是26280小时。则10*log2（26280/2000）=37.3℃，那么设计工作温度不能超过65℃。
But in fact, we generally know the design life, and then calculate the temperature rise according to the design life. For example, if the design life of the product is 3 years, that is 26280 hours. Then 10 * log2 (26280/2000)=37.3 ℃, and the design working temperature cannot exceed 65 ℃.
