Modified Sine Inverter #1

Design

• Simple design using readily available components.

• Easy to build and set up.

• Light weight suitable for portable operation.

• A small and compact design.

Circuit description:

The heart of this design is without doubt the microcontroller (IC102) a PIC12F509. All timing, frequency control, switching control of the power MOSFET's, and operation indication is derived through this device.

IC101 provides a stabilized 5v supply to the microcontroller. It is worth also noting  here C101, C102, and R101, these components form a low pass filter in the supply line feeding the voltage regulator, preventing  voltage spikes being presented to the microcontrollers supply rail. I missed these components in an early version of the inverter to my cost, loosing several power MOSFET's when the microcontroller latched  due to transients introduced into the supply rail by switching high currents to an inductive load.

TR101 the main inverter transformer 11.4 v- 0v - 11.4v primary 220v / 240v secondary is driven by T101,T102,T103, in parallel and T104, T105, T106, in parallel providing a switched bi phase supply from the main 12v battery feed. During normal operation T101, T102, and T103 are turned on for 5mS then off for 5mS, next T104, T105, and T106 are turned on for 5mS then off for 5mS, the cycle is the repeated.

Finally LED101, during operation flashes at a rate of 1/2 second on 1/2 second off.

        Modified Sine Inverter #1 schematic:

        Modified Sine Inverter #1 component placement / layout:

          Modified Sine Inverter #1 PCB bottom trace:

        Modified Sine Inverter #1 Firmware:

Original Files:

    Further to the details of the pages above - the original CAD files created using EAGLE PCB Design software are included below, along with associated PDF files of both schematics and PCB layouts suitable for printing directly. The firmware is also provided as both the assembly source code should you wish to change / alter the code for you own specific requirements, and HEX code for programming the PIC12F509 with a suitable device programmer.

    To use the original CAD files, they must be opened with EAGLE. Visit the CADsoft web site for more details, the software (including a freeware version), part libraries, tutorials, for EAGLE are available.

    Modified Sine Inverter #1 schematic PDF

    Modified Sine Inverter #1 PCB component layout PDF

    Modified Sine Inverter #1 PCB bottom track layout PDF

    Modified Sine Inverter #1 EAGLE schematic

    Modified Sine Inverter #1 EAGLE board

    Modified Sine Inverter #1 Source Code

    Modified Sine Inverter #1 HEX Code

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