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Re: 2 questions on resonance



Hi Malcom,

>Original Poster: "Malcolm Watts" <MALCOLM-at-directorate.wnp.ac.nz>
>
>Dear all,
>          After reading the responses on resonant rise, I would like
>to ask why it is said that resonant charging allows one to suck more
>power from a NST? I suggest that if that were true, one could set the
>gap wider than for a non-resonant situation and still have the gap
>fire at the 2Fmains rate. Any comments?

As you are canceling out the impedances involved, by matching XL
to XC (+90° -90° = zero), the only losses left in the circuit are the
resistive (DC) losses. This is (my guess) why resonant charging
will allow higher currents (and faster recharging of the cap = higher
BPS than 2*Fmains) to be sucked from a shunted xformer. While
you probably could open the gap wider and still get at least 2*F
BPS, the real question would be: Will your xformer survive this?
The operating (!) voltage of a NST is less than 1kV. (HV is used
only to ionize the gas in the tube). While the NST does have to
take the full rating (HV) at start, this is a start-up condition only.
My guess is that NSTs are too fragile (voltage wise) to take this
for very long. Of course, if you can do the same with an externally
shunted transformer, as John F. suggests, this might be worth
considering. On the other hand, a pig will supply you with all the
current and a ASRSG will get you any BPS you want.

Coiler greets from germany,
Reinhard


P.S: All of you still waiting for an answer from me: Please
bear with me, the amount of posts coming in is enormous!!
Thanks.