[en] Switch mode power supply rated 50V/60A is designed, developed and tested indigenously for biasing of Solid State Amplifier (SSA) for a re-buncher of the Rare Isotope Beams (RIB) facility at VECC Kolkata. In this paper we will present the design feature of this supply focusing hard switching and soft switching utilizing resonant tank network topology. Proportional and Integral (PI) controller is designed optimally to provide better time response with adequate robustness. Soft switching is used to mitigate switching loss and possibly reduce the generation of EMI in Semiconductor devices. In order to improve the initial design of the power supply unique power electronics features of PSIM have been utilized by performing simulations. In this paper, circuit topology, function of system components, simulated and experimental result of power supply are discussed. (author)