# Analysis of a circuit

#### Missio2468

Joined Mar 18, 2022
68
I have a parallel circuit RC circuit connected in series with a resistor R1, Ac voltage is connected to one end of R1 circuit. Dc source is connected to another end of RC circuit. How can we analyse the circuit.
ac voltage-r1-Parallel RC -Dc supply-circuit close.
I want to calculate the voltage across RC circuit.

#### dl324

Joined Mar 30, 2015
16,113

Is this homework?

#### WBahn

Joined Mar 31, 2012
29,489
MOD NOTE: Moved to Homework Help.

#### Missio2468

Joined Mar 18, 2022
68
Is this homework?

No it is not, I am trying to understand the logic of how the circuit works. attached the schematic

#### Attachments

• 38.3 KB Views: 43

#### Ian0

Joined Aug 7, 2020
8,940
It looks like the circuit that would be used to measure the AC mains voltage on an A/D with 0-5V input.

#### ericgibbs

Joined Jan 29, 2010
18,216
Hi M,
One point, if you are using that circuit in simulation, the bottom end of V2 is not connected.
E

#### Missio2468

Joined Mar 18, 2022
68
yes

#### Missio2468

Joined Mar 18, 2022
68
Hi M,
One point, if you are using that circuit in simulation, the bottom end of V2 is not connected.
E
bottom end of V2 is conected

#### Missio2468

Joined Mar 18, 2022
68
bottom end of V2 is conected
see there is a node in bottom connection

#### ericgibbs

Joined Jan 29, 2010
18,216
Hi M,
As I understand the connection point of two wires, it has to be a defined large 'dot'
Note the colour of a connected and unconnected point, Green to Green, not Brown to Green
E

#### Missio2468

Joined Mar 18, 2022
68
o
Hi M,
As I understand the connection point of two wires, it has to be a defined large 'dot'
Note the colour of a connected and unconnected point, Green to Green, not Brown to Green
E
View attachment 303215
Ok but the dc voltage is connected. I have corrected it. can you help me in analysing the circuit?

#### ericgibbs

Joined Jan 29, 2010
18,216
hi M,
For which V1 frequency and amplitude do you want to determine the voltage across C1 and R2?
E

#### Missio2468

Joined Mar 18, 2022
68
for
hi M,
For which V1 frequency and amplitude do you want to determine the voltage across C1 and R2?
E
For V1 = 230Vac and frequency = 60 Hz

#### ericgibbs

Joined Jan 29, 2010
18,216
Hi M,
Do you know how to calculate the Impedance of C1 at 60Hz?
E

#### Missio2468

Joined Mar 18, 2022
68
yes it will Xc =1/wC = 26.5k ohm

#### Missio2468

Joined Mar 18, 2022
68
Hi E,
I have gone through this link, I can calculate the parallel Impedance of Parallel RC. Impedance would be Z=
(2.68 x 10^3)−227.38j

Now the question still remains as what would be the voltage across RC circuit and Dc voltage source.
And series resistor and parallel Rc circuit would be Z total = (1.17268 x 10^6)−227.38j

#### WBahn

Joined Mar 31, 2012
29,489
Hi E,
I have gone through this link, I can calculate the parallel Impedance of Parallel RC. Impedance would be Z=
(2.68 x 10^3)−227.38j

Now the question still remains as what would be the voltage across RC circuit and Dc voltage source.
The easiest way to find that is to use superposition. Are you familiar with that analysis technique?