RE: SSTC design procedure- "magnetizing" current

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

Original poster: "Steve Conner" <steve.conner-at-optosci-dot-com> 

 >Would you please define "magnetizing current" as you see it as
 >applied to air-cored coils and explain how putting a capacitor in
 >series with a coil eliminates it?

The "magnetizing current" term was coined by Richie Burnett in

http://www.richieburnett.co.uk/sstate3.html

The untuned primary SSTC is not physically the same as the iron-cored
transformer model, which has the magnetizing inductance shunted across the
primary terminals. What we have been calling "magnetizing inductance" is
actually the leakage inductance, ie that portion of the primary inductance
that is not coupled to the secondary since k < 1.

In practice it seemed to behave sort of like magnetizing inductance, in that
it added a triangular component to the primary current waveform, which was
visible when the secondary was mistuned or damped, so that its own resonant
current was decreased. This is why we ended up using this term. But when you
think about it, it's misleading.

What I figured out really happens: The secondary is normally able to reflect
a capacitive reactance into the primary, to cancel out the leakage
inductance. But as you turn the power up, it is damped by streamer loading,
and no longer able to do this, so the load seen at the primary terminals
starts to look inductive. This causes hard switching and limits power
transfer.

Looking at it like this, it is obvious how the series capacitor works: it
series resonates the leakage inductance from the word go, so the secondary
does not need to do it.

 >Thanks for confirming what I understand to be the general state-
 >of-the-art regarding SSTC design.

Well, if you knows a better hole, go to it :P

Steve C.