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Pat. 9966868 United States, Int. Cl.22 H01F 30/14, H01F 27/28, H02M 1/12, H02M 5/14, H02M 7/06, H01F 30/12, H02M 1/14. Three-phase to nine-phase autotransformer : Appl. N 15/591281 : Filed 10.05.2017 : Pub. 08.05.2018 : / James Patrick Nunamaker ; Assignee Norlake Manufacturing Co ; NN p. : patents.google.com : URL: https://patents.google.com/patent/US9966868/en?oq=US9966868.html (дата обращения: ДД.ММ.ГГГГ).