Common Mode Choke related Confusion

[UroBoros]

HI

I am trying to do a low power SMPS using VIper22 based on example circuits and their design software.
Regarding the CM choke used for EMI filtering, different circuits have varying values for inductor and the capacitor(s).
Can anybody link me some documentation or details for designing A CM choke for a SMPS?

I have gone through some SMPS books , but detailed section of this was not found.
Please help.

Also which is more advisable, filter before bridge rectifier or after it?

Thanks

 

[IanP]

Here is a link to "good stuff": Common Mode Filter Design Guide
https://www.exergia.info/Lightning/lightning7.htm

Also which is more advisable, filter before bridge rectifier or after it?

Before ..

IanP

 

[UroBoros]

Thanks for the link going through it.
But it seems less on practical SMPS guidelines. Still very useful

Thanks a lot.