# Circuit Analysis - Superposition Theorem

#### Lukas1111

Joined Apr 3, 2020
2
Hello,

please can someone help me with this task. I have answears, but I am confused how to solve this kind of electrical circuit via superposition.
It is not my HW I am just just curious and i have been preparing for exams.

Picture in the attachment

#### WBahn

Joined Mar 31, 2012
27,383

Your original diagram appears to define I_U as the current flowing downward through the voltage source.

The symbol you are using for a voltage source is non-standard in my part of the world (I know that it is common in some places). Which is the positive terminal? The tip of the arrow or the tail? I'm guessing the tail.

But your notation on Circuit A indicates that I'_U is the current flowing downward through R4.

Circuit A is just a circuit to be analyzed. What do you get for your three variables of interest for it? Show your work!

Circuit B is just a circuit to be analyzed. What do you get for your three variables of interest for it? Show your work!

What do you get if you add the corresponding variables together?

#### Lukas1111

Joined Apr 3, 2020
2

Your original diagram appears to define I_U as the current flowing downward through the voltage source.

The symbol you are using for a voltage source is non-standard in my part of the world (I know that it is common in some places). Which is the positive terminal? The tip of the arrow or the tail? I'm guessing the tail.

But your notation on Circuit A indicates that I'_U is the current flowing downward through R4.

Circuit A is just a circuit to be analyzed. What do you get for your three variables of interest for it? Show your work!

Circuit B is just a circuit to be analyzed. What do you get for your three variables of interest for it? Show your work!

What do you get if you add the corresponding variables together?

Above the green line is task. I divided this circuit in two parts (via Superposition).
A: Power supply = Short-circuit.
B: Current source = disconnected terminals

From A I will get U_i´, I´_2 and I´_u
From B I will get U_i´´, I´´_2 and I´´_u

The final rusults are
U-i = U_i´ + U_i´´
I_2 = I´_2 + I´´_2
I_u = I´_u + I´´_u

I don´t know how to calculate U_i´, I´_2 and I´_u from A and the same for B.

#### WBahn

Joined Mar 31, 2012
27,383
Circuit A and Circuit B are just simple circuits having a single source. If you haven't learned how to analyze circuits with a single source then you are not ready to tackle circuits with multiple sources using ANY technique.

Go back and learn how to analyze simple (i.e., single-source) resistive circuits. If you don't you will just be digging yourself an ever deeper hole that will eventually cave in and bury you completely.

#### Wolframore

Joined Jan 21, 2019
2,566
That is kind of cool

you just open the current source. Solve
short the voltage source. Solve
then put both together. Simple

#### Wolframore

Joined Jan 21, 2019
2,566
So with voltage short think what’s the path what’s parallel and what’s series. Solve for current and voltage

same with current open but this one is easier

then add the two results, simple