emc filter desgining basics

[sri5496]

hi all,


pretty much a begginer in electronics field ...although did the engineering. but the practical part of it am pretty much a beginner.. am designing a smps ...using the power integration soft... but couldn't get the emi filter designing part... please do help me out(tried googling but most of them are not in much detail like from basics).. if there is any material or any thing where i can learn bit of filter designing would be gr8

thanks,
vamsi

 

[Darktrax]

Hmm - I tried Google, and there was a lot of links.
https://en.wikipedia.org/wiki/Electromagnetic_compatibility
www.emcia.org/documents/Reo/EMC Filters Guide.pdf

Try also keywords "common mode filter"

Essentially, if you have a device requiring filter, it can either be on prone to interference coming in from outside, or one generating interference that can mess up the outside. The ways it happens are many, including radiated, and conducted.

Addressing where conductors (cables, power leads, etc) can be filtered, the basic types are low-pass, or sometimes including band-stop or notch. Typically, the whole set of conductors can be passed through toroids to put inductance in the way of common-mode signals, and then also the conductors can be separately put through low pass filters comprising series inductance and parallel capacitance to a local grounding point. The most effective filters block HF currents through the ground conductor route.

Look in electronic supplier catalogs (Digikey, Mouser, RS, Farnell, etc.) and see the datasheets for typical interference suppression filters data sheets. You will find typical circuits with values. For filters put in AC mains power lines, you will find the limitations for capacitors ground leakage, and X-rated, and Y-rated safety considerations depending on where in the filter they are used.

It will not take you long before you get a good idea of EMC filter aims and methods. It is true that it can be a big subject, and there are subtle things to learn, but there is so much out there, I do not believe the Google search yields so little.

 

[sri5496]

Hmm - I tried Google, and there was a lot of links.
https://en.wikipedia.org/wiki/Electromagnetic_compatibility
www.emcia.org/documents/Reo/EMC Filters Guide.pdf

Try also keywords "common mode filter"

Essentially, if you have a device requiring filter, it can either be on prone to interference coming in from outside, or one generating interference that can mess up the outside. The ways it happens are many, including radiated, and conducted.

Addressing where conductors (cables, power leads, etc) can be filtered, the basic types are low-pass, or sometimes including band-stop or notch. Typically, the whole set of conductors can be passed through toroids to put inductance in the way of common-mode signals, and then also the conductors can be separately put through low pass filters comprising series inductance and parallel capacitance to a local grounding point. The most effective filters block HF currents through the ground conductor route.

Look in electronic supplier catalogs (Digikey, Mouser, RS, Farnell, etc.) and see the datasheets for typical interference suppression filters data sheets. You will find typical circuits with values. For filters put in AC mains power lines, you will find the limitations for capacitors ground leakage, and X-rated, and Y-rated safety considerations depending on where in the filter they are used.

It will not take you long before you get a good idea of EMC filter aims and methods. It is true that it can be a big subject, and there are subtle things to learn, but there is so much out there, I do not believe the Google search yields so little.

:grin: thanks alot ..