Re: cap firing voltage scope measurements question
In a message dated 99-06-21 16:16:18 EDT, you write:
<< Original Poster: "Malcolm Watts" <malcolm.watts-at-wnp.ac.nz>
> Hi all,
> I just had to add another musing to this topic. I think the
> voltage hike is really being "tuned in" by adjusting the rotary gap
> phase setting for best sparks. Again, I am amazed that a NST should
> take it on the nose without dying. I think the better option is to
>have a stiff transformer and a separate charging reactor in the
> secondary circuit to take half the charging voltage burden.
Not only is it more robust to use a stiff transformer and separate
ballast as I'm doing, but it allows a complete tuning of the charging
system, such that the peak cap voltage can be made to coincide
with the best firing phase. An NST system may require a
compromise in the firing time.
> the choke on the primary side of the pig achieves the same end but
> then subjects the transformer secondary to the entire voltage rise.
> One can weigh up the pros and cons of where to place the inductor
> CONS PROS
> Secondary side - high inductance needed takes half Vcharge burden
> - high V insulation reqd.
> Primary side - low inductance needed transformer primary and
> (transformed to a large secondary are stressed and
> inductor by turns ratio^2) core saturation may occur
> Malcolm >>
Well, pigs and PT's are designed to withstand great stresses.