finding Thevenin equivalent resistance across capacitor terminals for RC circuits

[PG1995]

Hi

While solving problems related to RC circuit, I'm having problem finding Thevenin equivalent resistance across the terminals of a capacitor. Please have a look on the attachment. It has my question there. Please help me with it. Thanks a lot.

 

[MrAl]

Hi PG,

Im not sure if you have heard of gamma correction, but your drawing needs gamma correction. Also, the size doesnt need to be that large either. I just thought i would tell you because it makes it easier to read after gamma correction and the size takes up less space.

It looks like you have the right idea but it's nicer to see the actual question the way you saw it first so i could get a better idea what is going on. I guess they just want you to solve for I(t) as shown? Didnt they give examples?
The resistance you seek is useful so you can find the time constant of the circuit. You also need to calculate the max voltage across C so i am wondering how they instructed you to do this or similar in whatever it is you are reading. The are different ways to do this so i'd have to see more of what you are reading to know exactly how they want you to do it.

In the mean time, here is a gamma corrected and resized diagram:

 

[PG1995]

Hi MrAl

I was told only to find Io(t) but I think there was a problem with the question. Don't you think? I have solved it. Here is the rest.

The page 1 is here.

 

[MrAl]

Hi,


Yes the cap is open circuit after a long time, so you are left with just a resistor array.

 

[PG1995]

Once again, sorry, MrAl.

Initially, I was interpreting the switch symbol in RC circuits wrongly. Actually, in the diagram they were saying that at t=0 the switch is opened. I think you also missed that!

The attachment has the solved problem.

Thank you for your help with so many queries.

Best wishes
PG