Autotransformers

An autotransformer, also known as a step-down transformer, is an electrical transformer with only one winding. The winding has at least 3 taps where electrical connections are made. Autotransformers have the benefit of being small, light and cheap compared to dual-winding transformers.

Autotransformers are used to step up or step down voltages in the 110V-115V-120V range and 220V-230V-240...