Dear Sachin,

thanks to your very detailed reply, now I know what you mean!

You wrote:

Now since the supply conditions in INDIA (Other than METROS) can be from 110V AC to 290-295V AC so finally we desided the have an SMPS.

Bloody hell, what a wide range of mains voltages!! Are you sure, that up to 295VAC must be expected? For continuous operation? Really 295VAC?
I ask, because the most SMPS I know can accept only 85VAC...265VAC. So, do you have one that can withstand 295VAC?

One solution could be the use of a standard mains transformer, which can withstand 295VAC. On secondary winding a standard rectifier and big storage capacitor is connected. Of course, voltage at this storage capacitor would widely change, when using either 110VAC input voltage or 295VAC. But even from this varying output voltage a simple step-down switcher like LM2576HV (or any other readymade part, of course) could fabricate a very stable voltage of let's say 9.0V. From this voltage all other voltages could then be made: 12V by the help of a DC/DC switcher and 5V by the help of LDO 5V regulator.

What current is drawn from 12V regulator, from the two 9V regulators and from the LDO 5V regulator? From rough calculation I think all currents summed up gives no more than 2A totally, am I right?

Kai