1. An electrical transformer in which the primary and secondary coils share a common winding, allowing voltage to be stepped up or down with high efficiency.
Usage: technical; electrical engineering

Examples

• The autotransformer is commonly used in power distribution systems to regulate voltage levels.
• An autotransformer requires fewer turns than a conventional transformer for the same voltage ratio.
• The technician installed an autotransformer to step down the 480-volt supply to 240 volts.
• Autotransformers are more compact and efficient than two-winding transformers in many applications.
• The laboratory equipment was connected through an autotransformer for safe voltage adjustment.