A power supply in an embodiment of the invention includes a plurality of dc—dc switching power converters, each of which has its input isolated from its output. The power converters are arranged with their respective inputs being series connected and their respective outputs being parallel connected in an embodiment of the invention. In another embodiment of the inputs are parallel connected and the outputs series connected. Each power converter includes an input filter in each of said dc—dc switching power converters and an output filter. Each power converter includes a sensorless current mode control circuit controlling its switching duty ratio.