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Re: That secondary behaviour, E-Tesla5, and Corum's thing...

Hi Terry & all-

The table in my prior posting on this subject came thru pretty well when
I read it off the List (after its passage thru all those countless miles
of copper, millimeters of aluminum, thousands of transistors, who knows
how many magnetic media?...I am continually astounded!); but I will
repeat it here, craftily forcing it to align by means of dots:

F, KHz.............95......148...185....249....425....516
.
Top V:Mid V....2:1.........................1:2.....8:1.....1:1.5
.................................Top.....Mid
................................. min. ..min.
Top:F phase..-90................180...+90...-90......+90
.
Mid:F phase..-90.........................-90..>+90.....+90

Also, in my later posting, I talked about the 1st 1/4 cycle--but I should
have said, 1st 1/2 cycle.  At the instant when the 1st 1/2 cycle of
"bottom" excitation goes thru its first zero-crossing, the 1st 1/2 cycle
of the "top" voltage is right on its maximum.  As to the behavior prior
to that, obviously the top voltage cannot instantaneously assume the
beginning rate of change of that 1st 1/2 cycle of excitation, which--from
my generator--starts right out climbing with the rate of change to be
expected at zero-crossing.  Instead, the top wave starts with zero rate
of change (naturally) & smoothly assumes the appropriate rate of change
within the 1st 1/4 cycle.  And I do hope someone will check me on all
this.

For excitation I used my old Wavetek 115 gated by my (also old) HP
8005--both >bears< to work on, I might add, the Wavetek because of its
construction and the HP because of its goofy circuits.  For fairness I'll
add that my Tek 7904 scope is just as bad or worse, in its way.  If
anyone owns one of those & has to work on its power supply, for instance,
God help them.  A pox on all those no-doubt-long-retired design
engineers!

As to loading of the secondary by the probe, no doubt its input
capacitance does that, but I wouldn't expect that to affect significantly
the kinds of things I measured.  Correct me if I seem to be wrong.

And once again, someone tell me what it is that's >"slow"<!

Ken Herrick

On Thu, 13 Apr 2000 21:45:01 -0600 Tesla List <tesla-at-pupman-dot-com> writes:
> Original Poster: Terry Fritz <twftesla-at-uswest-dot-net>
> 
> Hi Ken,
> 
> At 05:58 PM 04/13/2000 -0700, you wrote:
> snip...
> >
> >See my posting of yesterday about the experiment I did.  I don't 
> fathom
> >what is meant, in the above & in postings on other occasions, by 
> "slow": 
> >I see on my scope screen a) a short sine-wave burst from my sig. 
> gen.
> >applied to my secondary's bottom end (at resonance or elsewhere) 
> and b)
> >the voltage at the top end via a 10:1 probe.  At the beginning of 
> the 1st
> >cycle at the bottom, the voltage at the top starts to rise 
> immediately. 
> 
> I now see that you post of yesterday has the tabulation messed up 
> :-(
> Sometimes tabs don't go through all the Tesla list's servers intact. 
>  Sorry
> bout that.  Your results got chewed up pretty badly.  Perhaps you 
> can try
> to resend.
> 
> >At the instant when the 1st 1/4 cycle of the exciting wave passes 
> thru
> >zero, the 1st 1/4 cycle of the top signal has risen & is at its 
> peak;
> >that is, already, the top signal is dead-on at -90 deg. phase shift 
> (as
> >close as I can see it on Tek 7904, where I can expand that 1st 1/4 
> cycle
> >to 2 cm of screen or more)--and it remains at that phase 
> forevermore
> >(until the end of the burst, that is). 
> 
> Interesting!  I don't have a burst generator so I can't quite check 
> this at
> the moment.  Perhaps I can rig something up.  Do you think that your 
> scope
> probes (the one higher on the coil could have caused loading that 
> affect
> the measurements?
> 
> >
> >Now, I suppose one could say that the >voltage rise< of the top 
> voltage
> >is "slow"--but that's just the phenomenon you would expect where 
> you are
> >exciting an LC circuit, at resonance or wherever.  I see no 
> difference in
> >the behavior I describe either at or away from resonance; it's just 
> that,
> >at resonance, the top voltage keeps going up & up for a while. 
> 
> Disruptive coils usually "do their thing" in a relatively few 
> cycles.
> Perhaps the ring up of secondary coils needs to be examined more to 
> help
> solve this lumped, distributed, transmission line thing.  I think 
> you are
> dong really important stuff here.  You sort of have your finger on 
> the data!
> 
> Did you see that the phase started out at zero and then shifted to 
> 90
> degrees or was it always a constant 90 degrees throughout the burst?
> 
> Cheers,
> 
> 	Terry
> 
> >
> >So, what else is "slow"?  Is it >I< who am slow, or what?
> >
> >Ken Herrick
> > 
> 

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