A new single stage AC/DC converter with high power factor is proposed. The proposed converter gives good power factor correction, low current harmonic distortions, and tight output voltage regulations. This converter also has a high efficiency by employing an active clamp method and synchronous rectifiers. To verify the performances of the proposed converter, a 90 W converter is designed. The modelling of this proposed converter is performed using an averaging technique and based on these model equations, a detailed analysis is carried out. This prototype meets the IEC555-2 requirements satisfactorily with nearly unity power factor and high efficiency.