Sine wave Add-on to Square Wave UPS

[(unknown)]

I have just purchased a square wave UPS/Invertor and now I want to make a sine wave add-on for it at home.The unit is of 1000 Watt running on two 112 AH 12 V batteries (making 24 V in series)producing 260 Volts AC.

Could someone please send some schematics and guidelines to make one.I believe the last discussion on the subject took place quite a time ago and newer cheaper technologies must have appeared by now.

Also just to share, someone told me of a transformerless 1000W UPS.Can someone throw light on that.

I'll be grateful for the help

Azam

[dnix71]

It doesn't make sense to buy a square wave inverter and then try to make it into a sine wave inverter.

If you are determined to do it, http://mysite.du.edu/~etuttle/electron/elect16.htm

has circuit diagrams for sine wave generator circuits.

You will then need to use the sine wave generator to drive a lot of high power fet's or mosfets.

http://www.energychallenge.org/2001Reports/tamu.pdf is a Texas A&M fuel cell inverter design that is close to what you seem to want.