三瑩品牌的電解電容的壽命有2000小時，5000小時，10000小時的。如果選用2000小時的電解電容，按照每天工作12小時來計算的話，那么它的使用時長是2000小時/12小時就是166天嗎？很多人都會覺得就是這樣計算的，其實非也。
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.
正確計算
三瑩電解電容壽命的方法是要根據電解電容的工作環境來計算的。電解電容器的壽命主要受溫度的影響。通常，溫度每降低10°C 電解電容的預期壽命會增加一倍。因此，建議在低于規格書中保證的最高溫度之內，以盡可能低的溫度使用電解電容器。
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.
因為如果工作溫度超過規格書中最大的保證極限，電容器的電參數會下降，在最壞的情況下極有損壞的危險。因為電解電容是靠其內部的電解液來工作的，而電解液會不斷蒸發變少，溫度越高，蒸發越快，從而會大大減少電解電容的壽命。那么如何分析電解電容的溫升呢？
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?
要計算電解電容的最高工作溫度，必須考慮以下因素：
To calculate the maximum operating temperature of the electrolytic capacitor, the following factors must be considered:
環境溫度
ambient temperature
電容器紋波電流引起的溫升。這個值基本上取決于電容器的ESR，也就是其內部電阻，以及工作頻率。
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.
在同一電路板上，靠近電容器的其他電子組件（功率晶體管，穩壓器，功率電阻器等）傳導和輻射的熱量。
Heat conducted and radiated by other electronic components (power transistors, voltage regulators, power resistors, etc.) close to capacitors on the same circuit board.
電解電容結構
Electrolytic capacitor structure
壽命計算
Life calculation
計算公式
Calculation formula
L 1：在溫度T1時的保證壽命（以小時為單位），也就是電解電容規格書中給出的壽命值。
L 1: Guaranteed life at temperature T1 (in hours), which is the life value given in the electrolytic capacitor specification.
L 2：在溫度T2下的預期壽命（以小時為單位）。
L 2: life expectancy at temperature T2 (in hours).
T 1：電解電容規格書中給出的最高工作溫度。
T 1: The maximum operating temperature given in the electrolytic capacitor specification.
T 2：電解電容實際工作的最高工作溫度。
T 2: The maximum working temperature of the electrolytic capacitor.
舉個例子，例如某電解電容在最大溫度為105℃時，壽命為2000小時。根據計算公式，如果電解電容實際工作的最大溫度是40℃，可以計算出其工作壽命是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.
但是事實上我們一般是知道設計壽命，然后根據設計壽命計算溫升，比如說如果產品的設計使用壽命為3年，也就是26280小時。則10*log2（26280/2000）=37.3℃，那么設計工作溫度不能超過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 ℃.
