Design and Construction of 1 KVA Power Inverter System

Abstract

The inverter system is a device that converts the Direct Current (DC) from a battery to an Alternating Current (AC) which can be used for appliances. It does not only convert the current but also steps the voltage of the battery up to the required value. The inverter system does not require fuel to make it function, that makes it cheap.  The circuit has seven (7) embedded circuits in it; namely the oscillator circuit, which comprises the 4047 Oscillator Integrated Circuit (IC), It converts the DC current signal to AC signal at the same frequency. The current modification circuit, this comprises the switching transistors and the cascaded MOSFETs, which modifies the current to the desired input to the step up transformer which steps it up to the required voltage and current. The battery low circuit indicates when the inverter battery is low, while the battery full circuit indicates when the inverter battery is full. The change over circuit changes the source from AC main to battery automatically. The rectifying circuit charges the battery and lastly the inverter on circuit: this indicates when the inverter is on. The inverter system also has the battery full indicator, which helps to safe – guard the life of the battery while charging and it automatically switches of charging mode once the battery is full. The inverter system has timer for delaying the incoming current surge to protect the inverter from the large surge current and increase the working life of the inverter. The inverter was tested and the result obtained showed that it was able to bear the load up to 870 VA.