Dear Experts
please see the below circuit, if the value of C' is constant,
I can get the Laplace transform Uo(s) / Ui(s) = (1 + sRC) / [1 + sR(C' + C)],
but if the value of C' is not constant, i.e. C' = ω * t, where ω is a constant rotate speed, t is time.
then How to get the Uo(s) / Ui(s) ?
Thanks!
BR
jjl3
Hi Carolina,
I was asking asking 
JJi3, you should take into account that with varying C no longer this is valid
I = dQ/dt = C x dU/dt
but this
I = dQ/dt = d(C x U)/dt = dC/dt x U + C x dU/dt.
Kai
Thanks all of you!
at beginning I also think as: I = dQ/dt = d(C x U)/dt = dC/dt x U + C x dU/dt.
where Ui = Bsin(ω' * t), ω' is constant rotate speed of excitation signal.
hereunto, I do not know how to do next step.
dC/dt x U + C x dU/dt Laplace transfer to s*C*Ui + C * s*Ui = 2*sC*Ui ? There seems to be something wrong
If Bsin(ω' * t) is used instead of Ui, then how to get the transfer function?
so I have no idea
BR
jjl3
