Several control strategies have been defined for the control of high voltage power supplies based on resonant topologies. In recent papers, an optimal control based on minimizing the circulating energy in the converter has been proposed. This control is obtained by switching one of the branches of a full bridge inverter synchronously with the resonant current. In this paper, the problems associated to this issue are analyzed and a way to implement optimal control is proposed. Besides, the dynamic behavior of a PRC-LCC converter with a capacitor as output filter is obtained from the mathematical model and verified experimentally. From this study a second feedback loop is proposed to control the output voltage. Experimental waveforms will demonstrate the dynamic behavior of the closed-loop power supply under extreme variations: full load, short-circuit, no load.