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 ${\displaystyle {U}_{c}\mathrm {\colon } ={U}_{0}\cdot \left({e}^{-{\frac {t}{R\cdot C}}}\right)}$ ,${\displaystyle \tau \mathrm {\colon } =R\cdot C}$ Uo = Ladespannung Uc = Spannung am Kondensator τ(tau) = Zeitkonstante C = Kapazität R = Widerstand im Stromkreis t = Zeit, Dauer e = Eulersche Zahl (e = 2,718....) Kondensator gilt nach 5τ als entladen.
 Beispiel: ${\displaystyle k\Omega \mathrm {\colon } =1000\Omega }$ , ${\displaystyle {\mathit {\mathrm {\mu } F}}\mathrm {\colon } =0.000001F}$ ,${\displaystyle {\mathit {nF}}\mathrm {\colon } =0.000000001F}$ ${\displaystyle {U}_{0}\mathrm {\colon } =10V}$, ${\displaystyle R\mathrm {\colon } =5k\Omega }$ , ${\displaystyle C\mathrm {\colon } =100{\mathit {\mathrm {\mu } F}}}$ ${\displaystyle t\mathrm {\colon } =0.1s\left(0\dots 30\right)}$ ${\displaystyle \tau \mathrm {\colon } =R\cdot C={\text{0.5000}}s}$ ,${\displaystyle 5\cdot \tau ={\text{2.500}}s}$ ${\displaystyle {U}_{c}\mathrm {\colon } ={U}_{0}\cdot \left({e}^{-{\frac {t}{R\cdot C}}}\right)}$ ${\displaystyle {\mathit {plotxy}}\left(t,{U}_{c}\right)}$

### Strom vom Kondensator in Abhängigkeit von der Zeit

 ${\displaystyle {i}_{c}\mathrm {\colon } ={\frac {-{U}_{0}}{R}}\cdot {e}^{-{\frac {t}{R\cdot C}}}}$ ${\displaystyle {\mathit {plotxy}}\left(t,{i}_{c}\right)}$

### Zeitberechnungen

Z.B. Wann erreicht ${\displaystyle {U}_{c}\mathrm {\colon } ={U}_{0}\cdot \left({e}^{-{\frac {t}{R\cdot C}}}\right)}$eine bestimmte Spannung?

Umwandeln der Formel

 ${\displaystyle {U}_{c}\mathrm {\colon } ={U}_{0}\cdot \left({e}^{-{\frac {t}{R\cdot C}}}\right)}$

Beispiel: ${\displaystyle {U}_{c}\mathrm {\colon } =4V}$

${\displaystyle t\mathrm {\colon } =-R\cdot C\cdot \ln \left({\frac {{U}_{c}}{{U}_{0}}}\right)}$${\displaystyle t={\text{0.4581}}s}$

Z.B. Wann erreicht ${\displaystyle {i}_{c}\mathrm {\colon } ={\frac {-{U}_{0}}{R}}\cdot {e}^{-{\frac {t}{R\cdot C}}}}$einen bestimmten Strom?

Umwandeln der Formel

 ${\displaystyle {i}_{c}\mathrm {\colon } ={\frac {-{U}_{0}}{R}}\cdot {e}^{-{\frac {t}{R\cdot C}}}}$

Beispiel: ${\displaystyle {i}_{c}\mathrm {\colon } =1{\mathit {mA}}}$

${\displaystyle t\mathrm {\colon } =-R\cdot C\cdot \ln \left({\frac {-{i}_{c}}{\left({\frac {{U}_{0}}{R}}\right)}}+1\right)}$${\displaystyle t={\text{0.3466}}s}$