Thevinin's theorem for caps

[Aravind_tucson]

thevinins theorem

Can we thevinize a ckt consisting of capacitors...I read somewhere that thevinins theorem can be used for any linear ckt..
Or if somebody could explain how to solve this RC ckt belo for the final voltage across the RC load..

 

[Fahmy]

thevinins circuit

Thevin Theorem is more useful when working with pure sinuoidal input signals , otherwise it will need a lot of computation and transforms.
Any way of you need to solve this circuit using Thevinin you shall perform your analysis in S-domain as follows:
1) Calculate Vth as the Vout at no load :
Vth=Viin * (R1// (1/sC1)) / (R1// (1/sC1) + 1/sC2) ; C1=9u, C2=1u
Vin=10/s , Laplace transform of a unit step function multiplied by a factor of 10.
2) Calculate Zth as the output impedance when the input source is replaced with a short circuit .
Zth= R1// (1/sCeq) , Ceq=C1+C2

If there is no load connected to the output terminal then the output voltage will be equal to Vth. If a load is connected then :
Vout = Vth * ZL/(ZL+Zth)

Finally , you need to perform inverse laplace transform to get the output in time doman.