This paper presents a magnetic integration approach that reduces the number of magnetic components in a power supply by integrating magnetic components in two conversion stages. Specifically, in the proposed approach, a single transformer is used to implement the continuous-conduction-mode boost power-factor-corrected (PFC) converter and the dc/dc flyback converter. The integrated boost and flyback converters offer soft switching of all semiconductor switches including a controlled di/dt turn-off rate of the boost rectifier. The performance of the proposed approach was evaluated on a 150-kHz, 450-W, universal-line range boost PFC converter with 12-V/2.2-A integrated stand-by flyback converter.

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Abstract-In this paper, a method of maintaining high powerconversion efficiency across the entire load range and its circuit implementations are described. The proposed method substantially increases the conversion efficiency at light loads by minimizing switching and driving losses of semiconductor switches, as well as core losses of magnetic components. These losses are minimized by periodically turning off and on the power converter, and by controlling the converter so that when the converter is ON, it operates at the power level that exhibits the maximum efficiency. The performance of the proposed method was evaluated on a 500-W, 400-V/12-V dc-dc converter and a 1-kW ac-dc boost power-factorcorrection front-end.Index Terms-Efficiency optimization, light load, maximum efficiency, power management.

Despite the Blair government's claim that it wants to preserve the "enduring values" of the civil service, recent reforms seem to undermine long-standing constitutional conventions and the public service values that underpin them. This article examines the current debate by comparing the government's vision of a responsible bureaucracy as seen in its reform initiatives to the responses of other participants, especially the Committee on Standards in Public Life. It evaluates the effect of recent reforms on public service values and asks whether the approach taken by the committee to guard these values is sufficient.

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