IGBT is an Insulated Gate Bipolar Transistor. It is a highly efficient, fast power switching, three-terminal semiconductor device.This device is a combination of the mechanisms In MOSFET and BIPOLAR TRANSISTOR. The IGBT combines the simple gate-drive characteristics of the MOSFETs with the high-current and low-saturation-voltage capability of bipolar transistors using an isolated gate FET for the control input, and a bipolar power transistor as a switch, in a single device. The IGBT is used in medium- to high-power applications such as switched-mode power supply, traction motor control and induction heating.With controlled power input supported by a Gate fet and quick switching technique of a transistor. IGBT is an electronic appliance finding a wide range of application from air-conditioners, electric trains and cars, refrigerators and stereo with switching amplifiers.