Mathematical modeling of cross-regulation problem in flyback converters

The cross regulation problem in flyback converters with dual outputs is studied in this paper. The mathematical modeling for the cross regulation of the converter is presented. The experimental results agree well with the theoretical prediction. Further investigation also shows that extra turns wound around the outer leg of the core cannot only boost the voltage of the nonregulated output, but also improve the cross regulation of the converter provided that the extra turn number does not exceed the optimum value.