Capacitive idling Cuk converter with a novel control scheme

A novel control method is introduced for a capacitive idling (CI) class of switching power converters. Input voltage regulation is provided on the primary side via a novel, open-loop control strategy, while load current regulation is implemented on the secondary side via classical feedback control. Excellent line and load regulation characteristics from no load to full load are verified on a 250 W triple output prototype of a CI Cuk converter providing full regulation and independent protection of all outputs and simple synchronization of the primary and secondary side control circuits. Isolation is needed only in the main power transformer.