autotransformer

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autotransformer

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Etymology tree

English auto-

Proto-Indo-European *terh₂-der.

Proto-Indo-European *térh₂t

Proto-Indo-European *-ónts

Proto-Indo-European *tr̥h₂ónts

Proto-Indo-European *tr̥h₂n̥ts

Proto-Italic *trāns

Proto-Italic *trāns-

Latin trāns-

Ancient Greek μορφή (morphḗ)der.?

Latin fōrma

Latin fōrmō

Latin transformo

Old French transformer

Middle French transfourmerbor.

Middle English transformen

English transform

Proto-Indo-European *-yósder.

Proto-Italic *-āzios

Latin -āriusnom.

Latin -āriusbor.

Proto-Germanic *-ārijaz

Proto-West Germanic *-ārī

Old English -ere

Middle English -ere

English -er

English transformer

English autotransformer

autotransformer (plural autotransformers)

(electrical engineering) A transformer with a single winding, its output being taken from taps.
- 1990, Vincent Del Toro, chapter 2, in Basic Electric Machines, →ISBN, page 89:
  One of the principal features of the ordinary configurations of the transformer [...] is the electrical isolation that exists between the primary and secondary windings. [...] Whenever large transformation ratios are involved, safety demands that ordinary transformers be used. However, in instances where the transformation ratio is close to unity (which minimizes the hazard), a transformer employing a single tapped winding may be used with notable advantages.
  [...] This arrangement is called the autotransformer.