Ferrite cable clamp on shielded cable for EMC?

[cupoftea]

Hi,
Its noticeable how monitors etc have ferrite cable clamps on their cables. These are shielded cables.
Is it accepted practice to add ferrite cable clamps to shielded cables?

 

[FvM]

Surely accepted. It's an effective measure to reduce emissions by blocking common mode currents.

 

[cupoftea]

Thanks, yes , but isnt the cable clamp supposed to equalise go and return currents on the go and return conductors.......not involving the shield conductor?

 

[FvM]

I presume "go and return currents" is referring to what we call differential cable current in usual terms. It is not influenced by a common mode choke, because the voltage induced by the current in one conductor is also seen by the other. Respectively it can't "equalize" currents.