In this work, a 2.5kW automatic inverter system capable of converting a 24V DC to 220V AC 50Hz with an optocoupler circuit designed to provide feedback and hence stability of the output voltage have been designed and implemented. The major modules of the inverter system consist of an oscillator section, a Pulse Width Modulation (PWM) controller IC, MOSFETs driver section, a quad 2input NAND gate that serve as an interface circuit between the oscillator output section and MOSFETs driver section, inverter output section, a comparator for low voltage battery indication and overload detection. A change over circuit that comprise of electromechanical relay was made use of to provide automatic fast switching capabilities both in presence or absence of public power supply without voltage fluctuations supplied to loads during the power switching process. The system also has the ability to shut itself down whenever it senses a low battery voltage and load higher than the inverter capacity.
