what is a single phase auto transformer?

A single-phase autotransformer is a type of electrical transformer that uses a single winding to serve as both the primary and secondary winding. This design allows for voltage transformation with fewer materials, making it more compact and cost-effective than traditional transformers. In a single-phase autotransformer, part of the winding is common to both the input and output, enabling efficient voltage regulation and reduced losses, ideal for applications like motor starting and voltage adjustment.