i'm not sure if this is applicable to your situation, but one very
clever idea i've seen is to add a series diode before the capacitor, it
blocks negative going transients and effectively doubles the frequency
and halves the amplitude of noise signals.  i've seen this in audio
circuits but it could be useful anywhere there are noise/transient
problems i suspect. having the processor etc. in it's own box and away
from current carrying inductors might also help, nearby wiring can
couple current spikes and fast voltage transients very nicely into
nearby circuitry.

---------
 *************************************************
>
> ----- Original Message -----
> From: "Ian Rozowsky" <roz@CENTSYS.CO.ZA>
> To: <PICLIST@MITVMA.MIT.EDU>
> Sent: Tuesday, June 22, 2004 10:43 PM
> Subject: [EE]: Supressing fast transients
>
> > Hi all
> >
> > I'm currently putting an inverter design through compliance testing, and
> > have a problem with fast transients on the incoming power lines. I've
> added
> > common mode chokes and Y-cap to address conducted emissions, but
> electrical
> > fast transients are getting through, and dirupting operation of the
> > processor (16F870). I'm looking as some series inductors as a solution,
> and
> > was wondering if anyone on the list has had similar experiences, and how
> > they were resolved. Input currents are around 5A.
> >
> > Regards
> >
> > Ian Rozowsky
> > R&D Director
> > Centurion Systems (Pty) Ltd.
> > Box 506 Cramerview 2060 South Africa
> > roz**@centsys.co.za
> > ||Anti-spam - please remove the ** from the e-mail address before
> sending||
> > http://www.centsys.co.za
----------

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