This simple inverter circuit 12VDC – 220VAC contains a central part, the CMOS 4047, and converts a 12V DC voltage to 220V AC voltage. The 4047 is applied as being a astable multivibrator. At pin 10 and 11 we obtain a rectangular symmetrically signal that is amplified by two Darlington transistors T1 and T2 and lastly reaches the secondary coil of a transformer network (2 x 10V/60VA).
Main coil terminals voltage is 220 alternative voltage. To acquire a improved functionality use a toroidal core transformer with lowered losses. With P1 the output frequency could be regulated in between particular limits (50-400Hz).
Circuit source: Simple Inverter Circuit