Patent ID: 8385090
Filing Date: 2013-02-26
Classification: H02M

Abstract:
1. A power supply system, comprising an electromagnetic interference (EMI) filter circuit, a rectifier and filter circuit, a switch circuit, and a transformer connected in series, and a feedback circuit and a controller connected in series between an output of the transformer and the switch circuit, wherein the feedback circuit comprises: a voltage divider circuit, connected between the output of the transformer and the ground to generate a voltage dividing signal, wherein the voltage divider circuit comprises a first lossless element and a second lossless element connected in series between the output of the transformer and the ground, and the voltage dividing signal is generated at a node of the first lossless element and the second lossless element; a filter circuit, connected to the node of the first lossless element and the second lossless element, to filter the voltage dividing signal into a direct current (DC) signal; and a voltage and temperature compensation circuit, connected to the filter circuit, to do voltage compensation and temperature compensation to the DC signal to generate a feedback signal, and to send the feedback signal to the controller.