Steady state characteristics of push-pull converter with asymmetric operation for wide input voltage range

In this paper, the push-pull converter with asymmetrical operation is investigated for applying wide input voltage range. A switch is driven by asymmetrical gate waveforms in the investigated operation, and the primary side of the push-pull converter is configured two conversion circuits. Therefore, two different conversion ratios can be obtained by different numbers of turns in each circuit, and this method enables to handle the wide input voltage range. The operation principle and steady state characteristics are analytically and experimentally examined in this paper. As a result, the operating principle of the converter with asymmetrical operation has been analytically clarified, and it has been experimentally confirmed. Moreover, the operation limit of this converter has also been analytically and experimentally confirmed. The output voltage can be regulated 48V for all input voltage range of 100 to 400V, and the maximum efficiency is achieved 90%in low input voltage range.