The modified sine wave switching inverter power supply uses the PWM pulse width modulation method to generate the modified wave output. During the inversion process of the modified sine wave inverter, due to the use of dedicated intelligent circuits and high-power field effect transistors, the system's cost is greatly reduced. Power loss. And the soft start function is added, which effectively guarantees the reliability of the inverter. If the power quality requirements are not very high, and it can meet the needs of most electrical equipment, it still has 20% harmonic distortion, which will cause problems when operating precision equipment and cause high frequency to communication equipment. interference.