# Question for Common mode equivalent circuit

#### HW SEO

Joined Feb 15, 2021
4
Would the circuit on the left be the same as the circuit on the right?

#### HW SEO

Joined Feb 15, 2021
4

#### ericgibbs

Joined Jan 29, 2010
17,180
hi HW,
Welcome to AAC.
Is this a Homework or College assignment.?
E

#### HW SEO

Joined Feb 15, 2021
4
It's not homework, but there is a circuit in the paper like the picture on the left, and I want to briefly express it as shown on the right. Is the circuit structured correctly?

#### MisterBill2

Joined Jan 23, 2018
14,287
No, The current flow directions shown for the circuit on the right are not common mode currents. Those currents might be present at the same instant, but the currents shown on the right are "Normal Mode" currents.

#### HW SEO

Joined Feb 15, 2021
4
Does normal mode current mean differential mode current?
How can I configure the circuit diagram on the left simply in Common mode?

#### MisterBill2

Joined Jan 23, 2018
14,287
OK, my error in terminology. yes, "normal" is the differentil mode, sometimes called the "transverse mode." What does not seem correct to me are the two extra voltage sources, Vn and Vb.
What IS missing are the common mode currents which in every instance are flowing toward the right, where they then flow from the midpoint of the load resistance into "neutral", which is not shown.
So on the right side, the load current is shown correctly while the common mode current is not shown at all.
In theory, all of the common mode current would pass through C1 and C2 , into neutral. So the drawing on the right is not quite correct.