Inverter means a power converter which converts D.C. power to A.C. power. The type of output waveform defines that whether it is square wave or Sine wave invrter.

  Generally sine wave inverter is complex to make. Elaborate training is to be given for testing and trouble shooting. to make a cost effective design of Sine Wave inverter is a challenge.

  This is the less popular type of topology typically used in the home inverter segment. High end customer segment demands for sine wave inverter though it is costlier than square wave inverter.

  The topology used in this type is called as H BRIDGE type of inverter.

  Design comprises of a frequency generator, pulse width controller, four isolated outputs with dead band, feedback circuit with error amplifier, battery voltage monitoring circuits, load current and battery current sensing circuits, line voltage monitoring, change over mechanism, audio visual indications, reset / start switch etc. Circuits can be made using analog and digital ICs or by using microcontrollers. Experience says that using microcontroller based design proves to be more precise, less component count increasing reliability, compact in size, copy protected.

  Magnetics design is crucial as the price to performance ratio is to be maintained without loosing focus on quality. Transformer forms the major component in the inverter design. It is used to convert low voltage high current A.C. at input to High voltage low current output in inverter mode. While on line mode or mains mode it charges the battery by controlling the secondary voltage. For charging the battery, Boost Converter topology is commonly in use.   Normally 12 VDC or 24 VDC is most common D.C. input voltage and the battery used is of 12 V- 100 Ah to 200 Ah capacity.