MOSFET power inverter 500W circuit diagram. This MOSFET power inverter circuit will provide a very stable “Square Wave” Output Voltage. Frequency of operation is determined by a potensiometer and is normally set to 60 Hz. Various “off the shelf” transformers can be used. Additional MosFets can be paralleled for higher power. It is recommended to Have a “Fuse” in the Power Line and to always have a “Load connected”, while power is being applied.