Hi,
there seems to be a pretty large error or rather field of errors in the mentioned document. They all stem from the same problem, the definition of magnetic force F as driving field H and being a potential difference between equipotential surfaces between differential currents. While this works in some instances it is, quite simply, physically false. The H field is driven directly by current and does not require a current differential. A single line of infinite length or even an electron moving through space create closed loops of magnetic field around themselves.
Due to this initial error some of the explanations are contradictory or simply physically impossible. In chapter 5 there is a lengthy section describing how the leakage field is created by the sum of two equal contributions from the primary and secondary winding...even though one of those windings carries no current. To balance this problem (a current less winding creating a magnetic field) a second current is introduced to balance the first one to 0. That second current also contributes field to another part of the transformer...at that point a 0 current creates two energized magnetic fields (a violation of conservation of energy).
This then leads to another error in chapter 6A where the document claims that a gap outside of the center leg would carry no field because "Locating a gap in any of the outside surfaces of the core will not work, because to create a field within the gap would then require opposing conductors outside of the gap, i.e., outside of the entire core." which, as an explanation, violates Maxwell's second law (All magnetic fields need to close in on themselves eventually).
At that point the entire document is rendered worthless as all explanations of magentism and construction just stop making any sense.
Or am I completely mistaken here? Did I loose all understanding of magnetism since graduating university?
