Re: ballasting not revisited, Saturable, controllable cores

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Harvey Norris <harvich@xxxxxxxxx>



--- Tesla list <tesla@xxxxxxxxxx> wrote:

> Original poster: Steve Conner <steve@xxxxxxxxxxxx>
>
>
> >Still working on my 3 phase monster... 3 2950
> Superiors in a stack
> >for voltage control. A 20KW 3 phase generator
> driven by an Isuzu
> >diesel (not a factory unit!)
>
> Why are you bothering to lug a big variac stack and
> saturable
> reactors, when you can easily control voltage by
> adjusting the field
> excitation on the generator?
>
> Steve Conner
> http://www.scopeboy.com
Yes I was also going to comment on this matter as
there may be more here then mere control of output
voltage by the generator, if designed as the rotating
electromagnet field of an alternator by amount of
causitive field excitation. In this situation the
stator output can be tested for its current limitation
by shorting the output windings, (which also
determines R(int) by division of respective V and I
readings) and then increasing the field current until
the designated current output is reached. It is here
in making this assumptive field measurement that we
discover that the field itself being a DC pole face
assembly that mimics an AC output by design of
triangular flux leakage in mechanical rotation
interacting with the circular stator rim: this field
itself is a non-linear resistance, easily appearing
higher in resistance in rotation then when not in
motion. In fact it is not until the  stator output
voltage is doubled from its prexistant rotational one
that the amount of field current begins to
significantly reflect the availability of stator
current. In any case the fact that the primary of the
transformer can be ballasted by the amount of field
current in the AC alternator as a current limited
supply; this has further ramifications on the
transformer output end which is operating a primary
arc gap. In this case the effect of shorting the
alternator  stator itself is to cause its output
voltage to drop to its lowest possible operational
point, thus also withdrawing voltage for the operation
of the primary arc gap, making for  the possibility of
a better quenched arc, all of this dependent on the
time lag between currents on the secondary and the
primary, and how the secondary draw influences the
primary one.
HDN