The isolation DCDC power supplies have the advantage except

The isolation DC-DC power supplies have the advantage except: Very high ratio-stepping up Changing polarity Separate grounding Higher power You can use the following circuit for power factor correction if we sinusoidally-varying duty cycle: Boost circuit Buck circuit Buck Boost Push-pull circuit

Solution

19 . b CHANGING POLARITY as IT is DC supply it needs correct polarties .

20 . BOOST CONVERTER will boost the supply so that i t acts as a power factor corrction