commutator(redirected from Commutation relation)
Also found in: Thesaurus, Encyclopedia.
1. A cylindrical arrangement of insulated metal bars connected to the coils of a direct-current electric motor or generator, providing a unidirectional current from the generator or a reversal of current into the coils of the motor.
2. Mathematics In a commutative or noncommutative group, an element of the form ghg-1h-1 where g and h are elements of the group. If g and h commute, the commutator is the identity element.
1. (Electronics) a device used to reverse the direction of flow of an electric current
2. (Electrical Engineering) the segmented metal cylinder or disc mounted on the armature shaft of an electric motor, generator, etc, used to make electrical contact with the rotating coils and ensure unidirectional current flow
com•mu•ta•tor(ˈkɒm yəˌteɪ tər)
a. a device for reversing the direction of a current.
b. (in a DC motor or generator) a ring or disk assembly that works to change the frequency or direction of current in the armature windings.
2. Math. the element equal to the product of two given elements in a group multiplied on the right by the product of the inverses of the elements.