A DC to DC power converter is described that includes a transformer, a primary side connected to a primary transformer winding, and a secondary side connected to a secondary transformer winding. The secondary side comprises inductor-capacitor (LC) circuitry at an input, and a plurality of diodes providing uncontrolled rectification. A controller controls switching of the switching circuitry to apply voltage pulses to the primary transformer winding. The voltage pulses are separated by zero-voltage periods. A switching frequency of the switching circuitry is less than the resonant frequency of the LC circuitry.