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Estimating of Lifetime
Functional Polymer Capacitors FPCAP
Solid Electrolytic Capacitors with Functional Polymer
FPCAP RE Series
Calculation formula of lifetime
In general, calculation formula of lifetime of capacitors is appeared as follows.
FPCAP RE's calculation formula of lifetime is same as usual capacitors.
LX = L0 10(T0-TX)/20
Where,
LX (Hrs) =Life expectance in actual use
L0 (Hrs) =Life time
T0 (105 C) =Maximum operating temperature (105 C)
TX ( C) =Temperature of capacitor in actual use
On the other hand, temperature Tx adds the circumference temperature T as the
capacitor temperature and the generating temperature T by ripple current.
TX=T+ T
T ( C) = Ambient temperature
T ( C) = generating temperature
Furthermore, the generating temperature T by the ripple current is proportional to ripple
current, and is shown by the following formula. When applying the maximum permissible
ripple current Io to FPCAP RE, the generating temperature T is about 20 C at inside of
capacitor. All large capacitance types of RE serve as this temperature in general.
T = ( I / I0 ) 2 T0
I (A rms) = Ripple current in actual use
I0 (A rms) = Maximum permissible ripple current
T0 ( C) = Generated temperature value by maximum permissible ripple current
[About 20 ( C) ]
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