Origin of commutatorfrom Classical Latin commutatus (pp. of commutare, commute) + -or
- 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.
- Mathematics In a commutative or noncommutative group, an element of the form ghg −1 h −1 where g and h are elements of the group. If g and h commute, the commutator is the identity element.
- The arrangement of contact points in an electric motor connecting an external direct current power supply and the rotating electric coils that use the power, used to generate the AC voltages needed by the coils. The commutator is located at the rotating shaft of the motor, where two power contacts are swept underneath two metal brushes, supplying positive and negative voltage to the coils. When the motor has rotated 180 degrees, the power contacts are each moving under the opposite brush, reversing the polarity of the voltage supplied to the coils.
- In a group or an algebra, an element of the form ghg−1h−1 where g and h are elements of the group or algebra. If g and h commute, the commutator is the identity element. The commutator is often written [g, h].
- an electrical switch, in a generator or motor, that periodically reverses the direction of an electric current
- (mathematics) (of a group) an element of the form ghg−1h−1 where g and h are elements of the group; it is equal to the group's identity if and only if g and h commute
- (mathematics) (of a ring) an element of the form ab-ba, where a and b are elements of the ring, it is identical to the ring's zero element if and only if a and b commute