These transformers are used to convert DC supply (Normally taken from batteries or Rectification of mains) to AC by High Frequency switching of the Input DC through MOSFET/ IGBT Bridge. These transformers have high leakage inductance to filter out the switching waveform to a smooth Sine Wave with a minimum THD (Total harmonic distortion.) Additional leakage inductance is achieved either by placing the primary and secondary coils apart or by increasing the build of coils. Sometimes an additional shunt core is also placed, which connects to the input winding only and helps to smoothen the wave shape. These transformers can be manufactured using EI, UI or strip core as per rating of the transformers. These transformers are normally forced cooled because of high harmonic losses in them.