Hello buddies:
I hope all of you are fine.I have a problem relating to my project which is a boost converter.I wanted to made a boost converter from 12V to 400V, is it feasible or not? Moreover what is maximum conversion ratio?
old 3 dimensional TVs made ~20,000 volts to drive CRTs from 12 volts, which should answer 2 of your questions. I would start by studying old DC powered TVs
musm223393:
Hello buddies:
I hope all of you are fine.I have a problem relating to my project which is a boost converter.I wanted to made a boost converter from 12V to 400V, is it feasible or not? Moreover what is maximum conversion ratio?
Are we talking about DC or AC? There is NO such thing as a maximum conversion ratio. It all depends on how well you can wind an inductance.
Paul
With AC all you need is a step-up [u]transformer[/u].
With DC its NOT an easy thing to build yourself...
It IS easy to get high voltage spike with an inductor. An inductor "resists changes in current". If you run current through an inductor and then suddenly break the circuit you'll get a high-voltage spike as the magnetic field collapses and it "tries" to keep the same current flowing through an infinite resistance.
If you know the current you can put a resistance across the coil (so you don't have infinite resistance when you disconnect power) and you can use Ohm's Law to calculate the voltage spike. But it's only a spike and it won't hold that voltage for more than an instant.
This is the principal behind a DC-DC step-up converter, but there is feedback to control the voltage and a capacitor to smooth-out the voltage.
Note that when you step-up voltage you have to step-down the current (conservation of energy).
DVDdoug:
Note that when you step-up voltage you have to step-down the current (conservation of energy).
You don't "have to" step-down the current. 
It just happens. 
You "have to" realise this will be the case. 