The
original helix coil was invented by Chubb in 1911. It was an
air coils, wound using a flat wire in a helix manner.
Around
1990, Williamson patented a series of designs of magnetic core
inductors using the helix windings with claims that are sufficiently
different than the original helix design for patents to be granted.
Williamson patents claimed magnetic core inductor comprising
in combination of, among other things,
The
helical coils used in CWS's design follows the original Chubb's
design where the above 2 features are not incorporated. In CWS's
design, by having the output tabs the same width and cross sectional
area as the rest of the turns, we are able to reduce the manufacturing
cost substantially and make the coils mass manufacturable. This
is because we can use a same uniform strip of coils to do the
helix windings. CWS uses kapton insulation coating which has
better dielectric ( hi-pot) and offer higher temperature characteristic.
In
addition the helix coils are not compacted to make n+1 winding
characterized by a height substantially equal to the height
of a similar uncompacted coil of n turns. In CWS's coils, compacting
the coils to achieve the above feature will cause the insulation
layer to degrade and hence may lower the dielectric breakdown
of the insulation.
Therefore,
we believe CWS's HW series does not infringe of any known patents.
The
Williamson patents are currently owned by Schott Corporation.
Please refer to their patents for more information and their
patents expiration dates.
Note:
The above is the opinion of CWS's patent attorney and is not
necessarily the views of any other parties.
