Here is a 12 volt 100 watt DC to AC inverter with center-tapless transformer.
The inverter that I made this time uses power MOS FET as swtching device. I assum that this unit is used with the battery of car. So, the input voltage is +12V DC. The output voltage is AC 100V. However, input and output voltages aren't limited to this. You can use any voltage. They depend on the transformer to use. The wave form of the output is square wave. In my experience, it is usable with a lot of home electronics equipment. The electric power which is possible to handle is decided by the transformer to use. This time, I am using the transformer with 12V-10A(secondary side). So, it is possible to handle 120VA(about 100W).
I was asked about 220V output from some readers. The output voltage of the inverter is decided only in the transformer. You can use the transformer with 220V as for primary(input) and 12V as for secondary(output). At my circuit, primary and secondary should be used oppositely. Then, you will be able to get AC220V from DC12V.