Loss Reduction of a Multi-Input Transformer in a Flyback Converter

Making power supplies more compact by reducing transformer distributed capacitance which will in turn reduce loss is discussed. This is especially important for the multi-input transformers in flyback converters. It was found that the so-called sandwich winding, with a low-voltage winding and a secondary winding inserted between high-voltage windings, is effective for this purpose. Transformer loss can be reduced by about 17 percent by decreasing the distributed capacitance.