power inverter

A circuit that turns DC back into AC — the mirror image of a rectifier — by rapidly flipping the connection of a DC source so the load sees an alternating push and pull. Four switches in an H-bridge let current flow left-to-right, then right-to-left through the load, manufacturing a square AC wave; PWM then shapes it into a smooth sine.

This is what lets a solar panel or battery feed the grid, what spins a 60 Hz fridge from a 12 V car battery, and, in three-phase form, what drives every electric-vehicle traction motor and industrial servo. The switches are usually IGBTs or SiC MOSFETs, and the controller varies their PWM to set the output's frequency and amplitude — exactly the control behind variable-speed motor drives.