autotransformer
|au-to-trans-form-er|
🇺🇸
/ˌɔːtoʊtrænsˈfɔrmər/
🇬🇧
/ˌɔːtətrænsˈfɔːmə/
single-winding transformer
Etymology
'autotransformer' originates from Greek 'autos' (self) combined with English 'transformer' (from Latin via French), where 'auto-' meant 'self' and 'transformer' referred to a device that changes (electrical) voltage.
'transformer' comes from Latin 'transformare' (to change shape) via Old French 'transformer' and Middle English; 'autotransformer' is a 20th century English compound formed by prefixing 'auto-' to 'transformer' to denote a transformer that uses a single (self) winding.
Initially the parts simply meant 'self' + 'transformer' as a literal compound; over time it became the established technical term for a single-winding transformer with tapped connections.
Meanings by Part of Speech
Noun 1
an electrical transformer that has a single continuous winding serving as both the primary and secondary, with taps to provide different voltages; used for voltage step-up/step-down with lower size and losses than an equivalent two-winding transformer.
An autotransformer can provide a small voltage adjustment more efficiently and with less material than a two-winding transformer.
Synonyms
Noun 2
a device using an autotransformer in the starting circuit of an induction motor (autotransformer starter) to reduce starting current and torque.
The motor was started using an autotransformer starter to limit inrush current.
Synonyms
Last updated: 2025/11/29 11:52