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Pat. 9887638 United States, Int. Cl.22 H02M 3/335, H02M 1/32, H02M 5/458, H02M 7/48, H02M 7/487. Power conversion apparatus with frequency operation change based on input voltage : Appl. N 15/052274 : Filed 24.02.2016 : Pub. 06.02.2018 : / Yasuaki Norimatsu, Akihiko Kanouda, Yuuichi Mabuchi, Tadahiko Chida, Takuya Ishigaki, Takae Shimada ; Assignee Hitachi Ltd ; NN p. : patents.google.com : URL: https://patents.google.com/patent/US9887638/en?oq=US9887638.html (дата обращения: ДД.ММ.ГГГГ).