| 摘要 |
This invention relates to a power converter (1) comprising a converter input (3), a converter output (5), a power factor correction (PFC) stage (7) and an isolation stage (9). The PFC stage (7) is implemented by way of a buck PFC with low side drive and low side current sensing, There is provided a third stage, an intermediate buck pre-regulation stage (11), intermediate the buck PFC stage (7) and the isolation stage (9), Control of the power converter output voltage is achieved by varying the duty cycle of the intermediate buck pre-regulation stage (11) and therefore the isolation stage (9) may be an unregulated stage operated as a fixed DCDC voltage converter. The isolation stage (9) is operated as a 50%-50% duly cycle double ended stage. The configuration of power converter allows for a relatively inexpensive, highly efficient converter with 90%+ efficiency and simplified control. |
