Calculate Phasors of Current with 3 Capacitors

[JI567]

Is it possible to calculate phasors of current through 3 different capacitors in a circuit? The Supply voltage is given and the frequency is given. I was also given all the 3 capacitor values. Two of the capacitors are connected in parallel and the result of that in series with the remaining capacitor.

 

[mfb]

Why do you question the possibility?

 

[JI567]

It was a question I needed to answer few months ago but didn't know this forum then. Just want to clarify for the future. I still have a picture if you want to have a look.

 

[Dale]

It is certainly possible. There is a formula for adding series and parallel capacitors. There is also a formula for converting capacitance into impedance and then a formula for adding series and parallel impedances. Are you familiar with them?

 

[JI567]

Yeah. I added the parallel capacitors and added them up and wrote it as one impedence Z1. Then I added this impedence with the capacitor in series and got a total impedence Z2. Z2 came out as complex obviously and then I divided 10 V by the total impedence to get the Supply current. Then I multiplied Z1 by the Is to get the voltage across the parallel capacitors. So once I had the voltage I divided it by the impedence of each of the capacitors in parallel and getting I1 and I2. Supply current being the current for the 10 nanofarade as its in series. All of them were complex so I got the modulus and angle was +90 degree for all of the three currents. Correct me if I am wrong and if I am correct then just let me know...

 

[Dale]

Without checking the math, your approach sounds correct.