John Byrns wrote:

And I am glad you caught the two outer leg windings on Dave's
transformer that I missed, with that input it all makes sense now.

Note that in this kind of magnetic amplifier, the fluxes from the
reactance windings must cancel through the control winding. The reason
is that the control winding needs a lot of turns to make enough flux to
saturate the core with a small amount of current. On the other hand, the
reactance windings carry a lot of current, so they must have fewer
turns. Consider that this is a recipe for a transformer that puts high
voltage AC on the control winding unless the fluxes cancel there...

--
John Doty, Noqsi Aerospace, Ltd.
http://www.noqsi.com/
--
Specialization is for robots.