INTRODUCTION
TO THE TAPE WOUND CORE
The tape wound core approaches the perfect magnetic circuit
configuration. A review of the physical and magnetic characteristics
of the toroidal shape reveals many features which contribute
to this near-perfect circuit.
The effective air gap in the magnetic path is so small that it can be considered
non-existent. This minimizes losses, fringing, leakage, distortion, and
decreases the magnetizing force necessary to produce a given flux within
the material. Figure 1 illustrates the leakage flux phenomenon in comparison
to conventional "E" laminations and "cut cores."
In a toroidal core and coil assembly, the entire magnetic path is contained
within the electrical winding, further minimizing leakage flux and increasing
winding-to-winding coupling. Figure 2 illustrates this effect in comparison
to the lamination and the cut core.
The tape wound core configuration also provides a good degree of self-shielding
from external magnetic fields. The single, uniform, magnetic path causes
any entering magnetic field to split into two and induce equal but opposite
voltages in the two halves of a uniformly distributed winding. Thus, there
tends to be no voltage apparently induced in the total winding. This effect
can be achieved somewhat in a cut core, by splitting the windings into
two halves, with one half on each leg. However, the areas in which this
technique can be applied is minimal, because of the cost consideration.
Tape wound cores generate a small flux in the axial direction. This leakage
flux can be contained by ring laminations assembled to the top and bottom
of the core.
 
This manual gives complete ordering information and specifications for
Magnetic Metals' comprehensive line of Tape Wound Cores. It describes
the different materials, thicknesses, cases, coatings for Tape Wound
Cores and presents typical hysteresis loops, CCFR control curves and
core loss curves.
The
unique advantages of the Tape Wound Core configuration
in magnetic circuitry permits the most efficient application
of high permeability magnetic alloys.
This manual is a reference source for engineers involved in the application,
specification and/or purchase of these cores.
Originally published in early 1968, this updated edition of Magnetic
Metals' Tape Wound Core Design Manual reflects today's technology in
basic magnetic alloys, core casing, core testing and applications. It
is intended to fill the design needs of both the more experienced engineer
and the engineer new to Tape Wound Cores, their construction and application.
Also
available - for quick reference - is a Tape Wound Core
Design Chart which gives the designer instant access
to the most commonly used design formulae, core dimensions
and constants.
For specific engineering assistance or further information on any Tape
Wound Core or application discussed in this manual, call Magnetic Metals
Company (714) 828-4625 in Anaheim, CA. In Camden, N. J. (856) 964-7842.
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