I plan to have 28 x 12v small capacity batteries in series producing 336V DC. Each connection between the batteries will be tapped of to an individual MOSFET with all the Drains (I think) commoned together and connect to one side of the load. With an additional MOSFET at each end of the battery bank connected to the other side of the load providing polarity reversal. Then each of the 28 MOSFETS are turned on inturn using a look up table to switch them in at the right rate to approximate a sine wave. After it has completed 1/2 cycle. The MOSFET at the OTHER end of the bank is turned on the 28 MOSFETS are turned on inturn in the opposite order. That means that at any one time 2 MOSFETS are completing the circuit. =20 Therefore each MOSFET gets switched on 4 times per full cycle for about 250us (varying) and this occurs 50 times per second=20 Must be extremely careful to ensure they do NOT switch on at the wrong times as it will result in a direct short across a battery. And 336 V DC would have to be treated carefully. I feel that this should provide a very efficient 240vac source that should be able to drive a 10amp load. Justin Having stated the above considerations, MOSFETs are still cool. Can't say what you need without a lot more details though. Justin -- Brent Brown, Electronic Design Solutions 16 English Street, Hamilton, New Zealand Ph/fax: +64 7 849 0069 Mobile/txt: 025 334 069 eMail: brent.brown@clear.net.nz -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.