Keywords: multioutput, flyback converters, high frequency transformers, HFT, computer power supply, CPS, bridgeless converters, dc–dc converters, discontinuous conduction mode, total harmonic distortion, THD, conduction losses, power factor
Bridgeless single stage flyback converter–based computer power supply
A power factor corrected (PFC) bridgeless converter–based computer power supply (CPS) using multioutput flyback dc–dc converter is presented in discontinuous conduction mode (DCM) of operation. In place of the conventional diode bridge to convert ac voltage into uncontrolled dc voltage, two multioutput flyback converters are connected in anti–series across the single phase ac supply. The diode bridge at the front end is eliminated and the outputs of the two flyback converters are connected to two high frequency transformers, HFT–1 and HFT–2 respectively. Two multi–output flyback converters are operating alternately in positive and negative half cycles of the ac mains respectively to avoid the diode bridge at the front end. The proposed configuration of CPS offers low total harmonic distortion (THD) of supply current, low conduction losses due to the absence of diode bridge, high efficiency and good power factor (PF) with very simple control at full load as well as light load conditions. The performance of the proposed CPS meets the guidelines of international standards.