Patent 7969270 was granted and assigned to Echelon Corporation on June, 2011 by the United States Patent and Trademark Office.
A communications transformer in which the primary and secondary windings are each divided into equal halves is disclosed. One primary and one secondary half winding is disposed about one section of a magnetic core, while the other halves are disposed about a second, parallel section. Voltages in the primary half windings and secondary half windings caused by stray magnetic fields are subtracted.