Patent ID: 9042132
Filing Date: 2015-05-26
Classification: H02M

Abstract:
1. A noise suppression circuit for a power adapter comprising: an operational amplifier coupled between an alternating current (AC) neutral line on a first side of the adapter and a direct current (DC) ground line on a second side of the adapter, the first side of the adapter and the second side of the adapter separated by a transformer, wherein: an output and a first input of the operational amplifier are coupled to the AC neutral line, a second input of the operational amplifier is coupled to the DC ground line, and the operational amplifier is configured to cause current to flow from the DC ground line to the AC neutral line, or from the AC neutral line to the DC ground line, based on a noise between the AC neutral line and the DC ground line so as to attenuate the noise between the AC neutral line and the DC ground line, the noise being induced into a DC line on the second side of the adapter.