Page 85 - LAPLACE TRANSFORM

Example 4 (RC Series circuit)

Solve the current i(t) by using Laplace Transformation when S1 switch is closed.

Calculate the value of VR (t) and VC (t) when t = 0.3s. (Assuming zero initial

condition).

SOLUTION

By using Kirchhoff’s Voltage Law;

VR + VC = Vs

1 t
Ri(t) + ∫ i(t)dt = Vs
C 0

By applying the Laplace transformation method;

50
RI(s) + ⌈I(s) + qo⌉ =
s

By assuming zero initial condition;

50
RI(s) + ⌈I(s)⌉ =
s

20 50
100I(s) + ⌈I(s)⌉ =
s s

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