commutator
noun
Forms commutators
- noun An electrical switch, in a generator or motor, that periodically reverses the direction of an electric current.
- noun (group theory) A binary map in a given group G, given by [g, h] = ghg⁻¹h⁻¹, where g and h are elements of G, which yields the group's identity if and only if the group operation commutes for g and h.
- noun (ring theory) A binary map in a given ring R, given by [a, b] = ab − ba, where a and b are elements of R, which yields the ring's zero element if and only if the multiplication operation commutes for a and b.
Synonyms
Etymology
Back-formation from commutation (in the late 19th century), as is commutate (verb) too.
Webster’s 1913
- noun A piece of apparatus used for reversing the direction of an electrical current; an attachment to certain electrical machines, by means of which alternating currents are made to be continuous or to have the same direction.
Sources: Wiktionary · Webster’s 1913 — from the Wiktionary entry “commutator”, CC BY-SA 4.0. Details