Re: EMI filtration Questions

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "robert heidlebaugh by way of Terry Fritz <twftesla-at-qwest-dot-net>" <rheidlebaugh-at-desertgate-dot-com>

Gary: To answer your current question first. The measured pulse current into
the primary coil via the capacitror and spark gap is very high. My current
is only 400 amps while the current of other larger coils is well over 1000
amps.Think about how much current is required to cause 1/4" copper tubing to
get warm in a primary coil. You are correct about neading a defined subject
to answer a question.Since the question asked refered to commercial made
filters it was assumed to be  subject to power band pass. I limit my filters
to less tham 3x the input frequency in a low pass filter, so any frequency
above that is not valid.
    Robert  H 

> From: "Tesla list" <tesla-at-pupman-dot-com>
> Date: Thu, 05 Sep 2002 15:44:44 -0600
> To: tesla-at-pupman-dot-com
> Subject: RE: EMI filtration Questions
> Resent-From: tesla-at-pupman-dot-com
> Resent-Date: Thu, 5 Sep 2002 15:51:44 -0600
> 
> Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <Gary.Lau-at-hp-dot-com>
> 
> We can argue about EMI filters all day, but no one to my knowledge has ever
> defined exactly what it is that we're trying to accomplish.  Unless the
> objectives are rigidly defined, gauging success is impossible.  Are we
> trying to:
> * Eliminate conducted line interference at the tank frequency?
> * Eliminate conducted line interference at MHz frequencies, due to
> parasitic oscillations?  GHz oscillations?
> * Eliminate differential or single-ended conducted line interference?
> * Eliminate radiated interference at above frequencies?
> * Eliminate high voltage transients?  Single-ended or differential?
> * Eliminate all vestiges of interference on radios, TV's, and cordless
> phones in the house?  Neighbors house?
> 
> If you answer YES to all, you're being unrealistic and demonstrate that we
> really don't have a good handle on the nature and definition of the
> problem.  I also use a commercial EMI filter on my coil, but I make no
> claims about its effectiveness.  I did it because it was cheap and easy,
> but I did not make any before/after measurements, again, because we don't
> have a consensus on what it is that we're trying to reduce.  I can't
> measure what isn't defined.  Where did you get the 400-1200 Amp pulse figure?
> 
> Gary Lau
> MA, USA
> 
>> Original poster: "robert heidlebaugh by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <rheidlebaugh-at-desertgate-dot-com>
>> 
>> I like your post, but I take the reverse wiew. You state the use of  perfect
>> commercial filters. The last perfect man on this earth was treed in
>> palestine by Italians. This is my view. No commercial filter is made to take
>> the 400 to 1200 Amp pulse power of a TC. Commercial filters are good at what
>> they do, but farr from perfect so I use commercisal filters for what they do
>> well and use my own double Pi filters in each side of the power input to
>> take the brute force power of the TC ahead of a commercial filter. My
>> filters are not perfect, they take the slam of power while the commercial
>> filters clean up the remaining mess of ripple.Both doing there best.
>> Robert  H    
> 
> 
> 
>