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Re: Pulse Transformer

Original poster: "Paul Nicholson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <paul-at-abelian.demon.co.uk>

Robert H wrote:

> Resonant they are, sine wave they ain't

Well obviously the two sine waves have a finite line width because
they are both amplitude modulated by an exponential decay with time
constant Q/(pi*F), and their spectral line width is of the order F/Q Hz.

The point is they are sine waves because they don't have a significant
harmonic content. Their energy is localised to a small bandwidth, and
for that reason they are considered sinusoidal.

This is in stark contrast to your mistaken comments suggesting that the
TC spectrum consisted of the harmonics of the bang rate.

> This pulse has a basic frequency and multiple odd harmonics
> starting at the ppf frequency (120pps up to 200,000 Hz).

You are still thinking of the firing signal as a step pulse, leading
you to expect a harmonic series, which is not the case in practice.

Below breakout, the only source of non-linearity in the system is due
to the primary arc, but the relatively small harmonic content
generated by this is not significant for operation. As you've been
shown waveforms demonstrating the well known beat envelope of the
two dominant exponentially decaying sine waves, I cannot understand
why you cling to the untenable notion that the primary waveform is a

> examine your wave shape with a
> scope. You will find it to be non -linier.

Clearly you haven't actually done this. Below breakout, where is the
source of non-linearity?  There is none apart from the gap. Something
like 90-95% of the initial bang energy is shared between the two
lowest resonant modes of the resonator.  The majority of the remainder
goes into overtones resonances of the secondary.  The harmonics of the
two fundamental frequencies are very weak and insignificant in

> I chalange all the members of this group with government suport to
> build a perfect disruptive TC with perfect sine wave productive output

Who needs government support?  I've seen Terry produce some impeccably
clean waveforms using a solid state gap, below breakout.  For example,


for very clean set of waveforms.  Take a good look at the spectrum and
you'll appreciate that it is a far cry from the continuous spectrum
demanded by a pulse, or from the harmonic series required to form a
square or triangular shaped waveform.  You can see the two fundamental
modes of the coil are close together and placed either side of the
secondary's natural lowest mode of resonance.  These two exceed by a
factor of 10 the amplitude of the next highest component at around 
750kHz, which is the 3/4 wave mode of the secondary (not a harmonic of
the two lower modes).  And so on with the rest of the spectrum which 
shows some of the higher overtones of the secondary.

Notice the small harmonic content - the second harmonics of the two
lowest modes appearing at around 500kHz are below 1% the amplitude
of the main frequencies, that's 40dB down.  Notice also the baseband
component appearing due to slight rectification of the beat waveform.

As you can see, this is completely different from a pulse spectrum.

The TC can be used as a pulse transformer at frequencies below about
half the lowest resonant frequency, and then only when terminated with
an impedance somewhere near it's low frequency characteristic impedance.
Long thin solenoids are often employed in this way to produce a delay
line. Above about half the lowest resonant frequency - the quarter
wave,  you cannot find a terminating impedance that will suppress all
the resonant modes. In order to convey a pulse, the transformer must
couple all the significant component frequencies of the pulse. At TC
frequencies and above, the unloaded TC secondary will only support
signal components at its overtone frequencies, which are unlikely to
coincide with the harmonic spectrum of any repetitive pulse.

> so I can halucinate with the likes of you.

Do you really think electrical engineers just make all this 
stuff up?  Take a reality check.  Study your subject and make sure
you know what you're talking about, otherwise you do no one a service.
Paul Nicholson