UTOTRANSFORMER V/S POTENTIAL DIVIDER

At first sight, an autotransformer appears to be similar to a resistance potential divider. But this is not so, as described below.

1. A resistive potential divider cannot step up the voltage, whereas it is possible in an autotransformer.
2. The potential divider has more losses and is, therefore, less efficient.
3. In a potential divider, almost entire power to load flows by conduction, whereas in auto-transformer, a part of the power is conducted and the rest is transferred to load by transformer action.
4. In a potential divider, the input current, must always be more than the output current, this is not so in an autotransformer. If the output voltage in autotransformer is less than the input voltage, the load current is more than the input current.