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Pat. 11252378 United States, Int. Cl.22 H02M 1/00, G08B 3/10, H02M 7/02, H04M 11/02, H04N 7/18, H02M 7/217. Batteryless doorbell with rectified power delivery : Appl. N 16/733090 : Filed 02.01.2020 : Pub. 15.02.2022 : / James Steven Skeoch ; Assignee Amazon Technologies Inc ; NN p. : patents.google.com : URL: https://patents.google.com/patent/US11252378/en?oq=US11252378.html (дата обращения: ДД.ММ.ГГГГ).