铝电解电容寿命.doc

铝电解电容的寿命 电源产品中经常用到铝电解电容，他的寿命往往决定了整个产品的寿命。因此，了解如何计算铝电解电容的寿命很有必要。下面将我的一些心得整理出来，供大家参考。希望有助于提高国人的知识水平。说白了很简单，只不过很多人找不到相关的资料而已。同时也希望学校的教材中能够近早讲解相关知识。我尽量少翻译，因为我的语言能力及相关的专业术语还不行。仅供参考。 Chapter 1铝电解电容的特性 1.1 Circuit model （等效模型） The following circuit models the aluminium electrolytic capacitor’s normal operation as well as the over voltage and reverse voltage behavior. （此模型包含正常运行，过压，反压时的特性） CA Cc RP ESR L D = Anode capacitance (阳极电容)= Cathode capacitance(阴极电容) = Parallel resistance, due to dielectric (并联电阻) = Series resistance, as a result of connections, paper, electrolyte, ect. 等效串联电阻 = Winding inductance and connections 等效串联电感 = Over and reverse voltage 等效稳压管 The capacitance Ca and Cc are the capacitance of the capacitor and is frequency and temperature depended. （Ca and Cc，它的容量是频率及温度的函数） The resistance ESR is the equivalent series resistance which is frequency and temperature depended. It also increases with the rated voltage. （ESR是频率及温度的函数，随着额定电压的增加而增加） The inductance L is the equivalent series inductance, and it’s independent for both frequency and temperature. It increases with terminal spacing. （L是频率及温度的函数） The resistance Rp is the equivalent parallel resistance and accounts for leakage current in the capacitor. It decreases with increasing the capacitance, temperature and voltage and it increases with time. （Rp的大小决定了漏电流的大小，随着容量温度电压的增加而降低，随着使用时间的延长而增加） The zener diode D models the over voltage and reverse voltage behavior. Application of over voltage on the order of 50 V beyond the capacitor’s surge voltage rating causes high。（D模拟过压及加反向电压时特性） Leakage current and a constant voltage-operating mode quite like the reverse conduction of a zener diode. Applications of reverse voltage much beyond 1.5 V causes high leakage current quite like the forward conduction of a diode. Neither of these operating modes can be maintained for long because hydrogen gas is produced, and the pressure built up will cause failure. （加到电容两端的反向电压不能大于1.5V） 1.2 Capacitance （电容的容量） The rated c