B. Experimental Results
In order to validate the proposed concept, the values of the phase-shift ϕ and the rectified voltage Vr , which is controlled by the duty cycle D of the dc–dc converter, have been adjusted during the measurements to achieve maximum efficiency for each value of the output power. For the synchronous rectification, a zero-crossing detection of the rectifier input current IL is implemented and the full bridge (S1 − S4 ) is driven accordingly. The duty cycle D of the dc–dc converter is used to control the equivalent load resistance and hence the amount of power at the output of the system.