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1. Life Expectancy of a Power Supply
 Aluminum electrolytic capacitor is the shortest life expectancy parts in a power supply. Other parts, like resin, have also their life expectancies , but they are 20 - 30 or over years. So the life expectancies on electric devices generally are not problems.
 Aluminum electrolytic capacitor is the most important parts in terms of reliabiliety, and life expectancy of a power supply can be estimated by calculating the estimation of life expectancy of aluminum electrolytic capacitor.
 Life expectancy of aluminum electrolytic capacitor is determined by the amount of too much electorlyte, speed that electrolyte passes through a stopper rubber and evaporates, and temperature to determine the speed.
 The relationship between ambient temperature and capacitor life has been confirmed to follow ARRHENIUS' equation:

  Life Expectancy of Electrolytic Capacitor : L = Lo x 2 ^{(T1-T2) / 10}
      Lo : Lifetime Under Maximum Rated Operating Temperature
      T1 : Permissible Maximum Temperature
      T2 : Capacitor Temperature on operation

 Life expectancy is determined by a coefficient depending on temperature, based on Lo.

2. Influence to a Power Supply
  Life expectancy of aluminum electrolytic capacitor is a condition that capacitance is below tolerance, tan gets large, or leakage current gets large.
 Aluminum electrolytic capacitor is used in a power supply. When it comes to life expectancy, each circuit is affected differently.
 Table 1 shows situation of each circuit and influence to a power supply.


3. Note
 Since life expectancy of alunimum electrolytic capacitor is determined by ambient temperature, a power supply should be used a well-ventilated place.