What is the function of an autotransformer in industrial applications?

An autotransformer is primarily designed to alter voltage levels in electrical systems efficiently. Its fundamental function in industrial applications is to step up or step down voltage using a single winding, which acts as both the primary and secondary winding. This design allows for a more compact transformer with fewer materials compared to a traditional transformer, which requires separate primary and secondary coils.

When stepping up voltage, the autotransformer increases the voltage level while maintaining the current level, which is advantageous in applications where higher voltages are needed to transmit power over longer distances with minimal losses. This capability makes autotransformers particularly useful in applications such as starting large motors or adjusting voltage in electrical distribution systems.

The other options address functions that are not inherent characteristics of an autotransformer. While it can reduce voltage, its primary designation is not focused on voltage reduction to the same extent as stepping up. Autotransformers do not provide isolation between circuits, which is a critical function of other transformer types. Lastly, they are not used for supplying power directly; their purpose is to modify voltage levels rather than serve as a direct power source.