Patent ID: 9590519
Date: 2017-03-07
CPC Classifications: H02M,Y02B

Claim:
1. An adapter, comprising: a rectifier with an input and an output; a step-down transformer with a primary coil and a secondary coil, wherein the primary coil is coupled to the output of the rectifier, and wherein the secondary coil comprises a first end tap and a second end tap; a first switch and a second switch, each of the first switch and the second switch having a first switch end and a second switch end, wherein: the first switch end of the first switch is coupled to the first end tap and the second switch end of the first switch is coupled to ground, and the first switch end of the second switch is coupled to the second end tap and the second switch end of the second switch is coupled to ground; and a controller coupled to the first switch and the second switch; wherein the controller is configured to control a primary positive voltage and a primary negative voltage across the primary coil, wherein the primary positive and negative voltages cause a secondary positive voltage and a secondary negative voltage across the secondary coil; and wherein the controller is configured to alternate activating the first switch and the second switch by activating the first switch during the secondary positive voltage and activating the second switch during the secondary negative voltage based on the secondary positive and negative voltages across the secondary coil.