Methods and apparatuses are disclosed for power conversion in fuzes for projectiles. Fuze electronics in the projectile control detonation of the projectile. A rectifier converts pulses from a setter signal to a DC power source signal. A voltage monitor coupled to the power source signal generates a source voltage indicator and a current monitor coupled to the power source signal generates a source current indicator. A combiner generates a supplied power level indicator in response to a combination of the source voltage indicator and the source current indicator. A DC-DC converter uses the supplied power level indicator when converting the power source signal to a power output signal to adjust a current level of the power output for efficient charging of a charge storage device and delivery of power to the fuze electronics.