Bridgeless Multiple Output SMPS

Switched mode power supplies (SMPSs) are used for powering up different parts in a personal computer by developing multiple dc voltages from a single-phase ac voltage. Normally, a bridge rectifier (BR) followed by a filter capacitor is used at the front end of these SMPSs. BR causes significant reduction in the power quality. This thesis deals with the design, analysis, simulation and development of a power-factor-correction (PFC) multiple output switched-mode power supply (SMPS) using a bridgeless buck–boost converter at the front end. Single-phase ac supply is fed to a pair of back-to-back-connected buck–boost converters to eliminate the diode bridge rectifier, which results in reduction of conduction losses and power quality improvement at the front end. The operation of the bridgeless buck–boost converter in discontinuous conduction mode ensures inherent PFC operation and reduces complexity in control. For providing isolation and multiple output a forward converter (FWDC) with active clamping circuit is proposed. Simulation of the proposed converter is done using MATLAB R2014a. Finally an experimental set up of 30W is set up in laboratory and verified the feasibility of the proposed topology.