Dual switcher flyback structure for LED driver

摘要

The present document relates to driver circuits which are configured to reduce or remove flicker of SSL devices. A controller (306) for controlling a power converter to convert electrical power at an input voltage (230) into electrical power at an output voltage (231) is described. The power converter comprises a first switcher stage comprising a primary winding (320) of a transformer (307) in series with a first power switch (202) and in parallel to the input voltage (230). The power converter comprises a second switcher stage comprising an auxiliary winding (322) of the transformer (307) in series with a second power switch (503) and in parallel to a reservoir capacitor (501). A secondary winding (321) of the transformer (307) forms an output of the power converter. The controller (306) is configured to determine whether the input voltage (230) is greater or smaller than a pre-determined voltage threshold (403); to operate the first switcher stage during a first time period when the input voltage (230) is greater than the threshold (403); and to operate the second switcher stage during a second time period when the input voltage (230) is smaller than the threshold (403). (Fig. 5)