1. AUTOTRANSFORMERS

2. Advantages of Autotranformers
As comparing with a two winding transformer of same rating autotransformer has following advantages,
Require less Copper
Operates at higher efficiency
Better Voltage regulation
Smaller Size
Smaller Exciting current

3. Disadvantages of Autotranformers
There is a direct connection between primary and secondary ie output is no longer dc isolated from input
Not safe for using stepping down higher voltage
Short circuit current is much larger than for the 2 winding transformer of same rating

4. Applications of Autotranformers
Used to compensate voltage drop in transmission and distribution line known as BOOSTER TRANSFORMERS
Used to reduce voltage supplied to ac motors during starting
Used for continuously variable supply

5. Autotranformers

6. Autotranformers