This is the schematic diagram of 300W power inverter circuit. The inverter uses power transistor MJ15003 for final amplification. You may replace the MJ15003 with 2N3773 if you have difficulty to find MJ15003 transistor. The inverter will convert 24VDC to 220VAC voltage.
Here the PCB layout design for 300W Power Inverter Circuit:
Source: dcinverter.blogspot.com