Various applications of autotransformer are :-

• Autotransformers are used to compensate for voltage drops in transmission lines. When used for this application, these are known as booster transformers.

• Autotransformers are used to obtain a variable supply.

• It is also used as a reduced voltage starter for the Induction motor.

• They offer variable voltage control in the laboratory setup: as we move the sliding contact, virtually all of the coil can become the series coil. Therefore, the entire coil must be sized for maximum current.

• They are generally used to connect transmission lines of slightly different voltages ( e.g., 115 kV and 138 kV or 138 kV and 161 kV)

• They are used to adjust the transformer output voltage in order to keep the system voltage constant with varying load.