[Firam]

It seems like there is a disproportionate number of electrical/electronic/computer engineers here. So I'll take a chance that someone knows. I'm stuck on a problem. How do I reduce this circuit? I want to use Wye to Delta but how does it work with capasitors?

Thanks very much. So far my google searches have brought up nothing.

 

[chesebert]

eqiv C = 32/3F (I know this is wrong already..misread the schematic)

ok... I am 60% sure of my answer..someone check my answer!!!!

I should really be 100% sure of these 0 order circuits

 

[Firam]

How did you get that answer?

 

[chesebert]

(1/(1/4+1/2))*2+8

can someone else verify this?

 

[Firam]

Hmmm. You might be right but that looks strange. There are no caps in series or parallel, this is a three node circuit.

Looking at what you did, you add the 2F and 4F in series. Multiplied by two for both branches then added the 8F in parallel. So the equivalent circuit is:

Which is exactly like the original one, except the 8F cap is moved. Can it go either place?

 

[chesebert]

look into the 8F and I see C4 and C1 in series, C5 and C2 in series.

 

[Firam]

Quote:

Originally Posted by chesebert /img/forum/go_quote.gif look into the 8F and I see C4 and C1 in series, C5 and C2 in series.

You look into the 8F. I don't understand. Maybe that is something we haven't covered.

 

[chesebert]

look into the nodes across 8F.

what's the right answer?

 

[Firam]

I don't know the right answer. It is an extra credit problem for Physics, but since I know circuits I thought I could figure it out. I'll just ask my circuit teammates what they think. I wish I could just put it into Multisim/PSPICE but I can't figure out how I get them to measure capacitance.

I kinda see what you are talking about but don't quite understand it.

 

[chesebert]

Quote:

Originally Posted by Firam /img/forum/go_quote.gif I don't know the right answer. It is an extra credit problem for Physics, but since I know circuits I thought I could figure it out. I'll just ask my circuit teammates what they think. I wish I could just put it into Multisim/PSPICE but I can't figure out how I get them to measure capacitance. I kinda see what you are talking about but don't quite understand it.

life is easier when you use Cadence

 

[chesebert]

I just redrew the circuit..now I am serious questioning my answer. I was looking into the wrong end

I guess I wouldn't even reduce this circuit I just use nodal analysis..much easier IMO

damn the equiv circuit!

 

[rb67]

Looks kinda like a wheatstone bridge circuit with caps in place of resistors.... interesting....

 

[chesebert]

ok..I used nodal analysis.

C3 is not even in the equation now! What

I just have C equiv = 1/(1/C1+1/C2) + 1/(1/C4+1/C5)

 

[chesebert]

bump..I need to know the answer. 165 views and no help...

 

[rb67]

I'm wondering, if you assume steady state, wouldn't the voltage drop across the middle 8F cap be 0 and then we can disregard it? This then just becomes 2 sets of 2 caps in series in parallel.

I'm going to ask around to see if any of my friends can figure it out.