How to Make a 200 Watt Transformerless Inverter Circuit

    A 12 V car battery can be used as the 12V source.
    Use the POT R1 to set the output frequency to50Hz.
    For the transformer get a 9-0-9 V , 10A step down transformer.But here the 9-0-9 V winding will be the primary and 220V winding will be the secondary.
    If you could not get a 10A rated transformer , don’t worry a 5A one will be just enough. But the allowed out put power will be reduced to 60W.
    Use a 10 A fuse in series with the battery as shown in circuit.
    Mount the IC on an IC holder.
    Remember,this circuit is nothing when compared to advanced PWM inverters.This is a low cost circuit meant for low scale applications.

Inverter Design Tips.

The maximum allowed output power of an inverter depends on two factors.The maximum current rating of the transformer primary and the current rating of the driving transistors.

For example ,to get a 100 Watt output using 12 V car battery the primary current will be ~8A ,(100/12) because P=VxI.So the primary of transformer must be rated above 8A.

Also here ,each final driver transistors must be rated above 4A. Here two will be conducting parallel in each half cycle, so I=8/2 = 4A .

source: circuitstoday.com