A new soft-switching converter technique is introduced which employs small saturable reactors and phase-shift modulation. This considerably reduces switching losses with no substantial increase in conduction losses. The proposed soft-switching concept and its modifications to full-bridge DC-DC power convertors are shown and discussed. These convertors can be realised by only a few additional small magnetic components with conventional full-bridge PWM convertors. The steady-state characteristics are verified analytically and experimentally through 350 W, 500 kHz breadbords.