The following presentation is a tutorial in the field of ferrite toroid design
focusing on the area of Local Area Networks (LAN). The formulas in the
chapters are either standard magnetic pulse transformer design derivations,
or personally derived estimating formulas for calculating the parasitic
parameter values.There has been a attempt to create these formulas from
the placement of wire on the toroidal core. This is not perceived as a perfect
depiction of the parameters, but as an estimate based upon the wire being
placed upon the core evenly without the presence of winding errors such as
gaps or wire crossovers. The results of these human winding variations
would increase the calculated values. However, this paper presents a fairly
accurate picture of the functional performance based upon the data inputs.
These created formulas should be considered as a "first cut" at the design to
try to save time. The final outcome is achieved when the finished coil designs
are functionally tested and the design is fine tuned to meet the IEEE specific-
Copyright 2006 - Dallas Dean
Dallas Dean has over forty years of experience working in the field of
magnetic pulse transformer design. Designs include shift registers, counters,
pulse transformers,filters, Token Ring and LAN magnetics to suppress EMI noise.
As the electrical member of one design team, he holds two patents in shielded connector design. Dean holds a B.S. degree in electro- mechanical engineering from Lowell Technological Institute (Lowell University). He can be contacted via email at firstname.lastname@example.org.