Re: gEDA-user: basic anti-EMI design q

["John Luciani" <jluciani@xxxxxxxxx>]

You can get some good power supply application information
at Vicor (www.vicr.com).

>> Be sure and address both differential and common mode signals.  X
>> and Y caps in line filtering terms.  In other words, put some C
>> between the lines and also to ground.

> The switcher only provides +5 and ground.  What's the third line?

The X cap would go across the +5V and ground. You would use two Y caps
-- one from +5V to earth ground and the other from ground (or return)
to earth ground.

>> For an AC signal, you can put a common mode choke on the incoming
>> line.  By this I mean, take the pair of wires that bring 24 VAC in
>> and wrap them around a magnetic core.

> This can be done just off the board, yes?  Just a ferrite on those
> lines?

This depends on the frequency you are trying to filter. I would think
you would be better off with a larger inductance. Something like a
few mH toroid.

(* jcl *)




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