| 主权项 |
1. A switching converter for converting an input AC voltage to an output DC voltage, comprising:
a primary side, the primary side comprising: first and second AC input nodes for receiving an input AC voltage or a rectified AC input voltage: a first switch having a first end connected to the first AC input node and a second end connected to a common switching node; a second switch having a first end connected to the common switching node and a second end connected to the second AC input node; a first resonant circuit comprising a capacitor in series with a primary winding of a first transformer, wherein the first resonant circuit is provided between the common switching node and the second AC input node, wherein the first resonant circuit has a first pair of resonant frequencies comprising a series resonant frequency and a parallel resonant frequency; a secondary side comprising a secondary winding of the first transformer and at least one rectifier for rectifying the voltage from the secondary winding, a second resonant circuit provided between the same nodes as the first resonant circuit, the second resonant circuit comprising a second primary winding of the transformer, wherein the second resonant circuit has a second pair of resonant frequencies comprising a series resonant frequency and a parallel resonant frequency; and a controller for operating switches, wherein the controller is configured to operate the switches using a variable frequency, wherein the controller has a first mode of operation in which the switching frequency is confined to a first frequency range and a second mode of operation in which the switching frequency is confined to a second frequency range. |
