Foil windings for magnetic circuit elements such as chokes, coils, transformers, and inductors are used in a wide variety of power conversion applications. Foil-wound magnetic devices are particularly useful in high-efficiency switching power supplies operating at frequencies between 20 kHz and 1 MHz, including those within personal computers.
For high currents, foil windings are more practical than very large litz-wire bundles, and they can have lower AC resistance than solid wire. But when foil windings are upsized for low resistance at high currents, increased foil thickness does not decrease AC resistance proportionately because of skin and proximity effect losses. Similarly, additional parallel windings are rarely effective because of uneven current distribution between windings.
Dartmouth inventors have devised a way to evenly share current between multiple, parallel, foil windings.
Dartmouth College recently filed a patent application on this new technology for high current, low loss, foil-wound magnetic circuit elements that provide for even sharing of current between multiple windings.
This technology is claimed in the published PCT Application No. PCT/US09/34729. We are seeking an industrial partner interested in its commercialization. (Ref: J433)
Last Updated: 7/24/12