A Simple Mains Inverter

Circuits that convert a DC supply into a 50 Hz AC supply are called inverters. Commercial units are notable for their small size, high efficiency and high power output. A simpler approach using a standard mains transformer is however more than adequate to power a TV set and satellite receiver from a 12 V vehicle battery.

- Replaced 74HCT ICs (7 V) by CMOS types (15 V)
- Consequently the two npn driver transistors are omitted.
- 3.9-volt zener diode inserted in the gate lines of the power MOSFETs. These create a voltage gap to prevent both MOSFETs conducting simultaneously during switchover.
- Added snubber network (R9/C7 is updated schematic).
- Added mains voltage caution in circuit diagram.

The download (left) contains the updated circuit diagram in pdf format and the corrected PCB artwork with all files (schematic, layout, components in .bmp, .jpg and .ps format), as well as the original Eagle files supplied by the author and datasheets from the semiconductor manufactures.