Yogesh,

So you took time to analyse the common boost-buck voltage stabilizer that is normally used for "safeguarding" fridges and AirCons?

Tell you something : Dont waste time.

If you are planning to do it commercially, it is a NON_STARTER. You cannot stand the competiton and copy-cats.

If you are doing it to learn MCU's then you have to get your fundamentals very clear, going by the 4 questions you had asked.

I am not discouraging you - but your generic questions will not fetch focussed answers and the thread will stary and be wound up fast.

Spend lots of time on the tutorials on the left.

Cheers

Raghu