commutator

noun

com·​mu·​ta·​tor ˈkäm-yə-ˌtā-tər 

-yü-

1

: a series of bars or segments connected to the armature coils (see armature sense 2b) of a generator or motor so that rotation of the armature will in conjunction with a set of fixed brushes (see brush entry 2 sense 3) convert alternating current into direct current

Note: In a generator, a commutator results in an output of direct current. In a motor, the commutator converts incoming alternating current into direct current before using it to generate motion.

2

: an element of a mathematical group that when used to multiply the product of two given elements either on the right side or on the left side but not necessarily on both sides yields the product of the two given elements in reverse order

Examples of commutator in a Sentence

Recent Examples on the Web

The commutator and wires inside the fuel pump may be fused incorrectly, potentially causing the fuel pump to fail. —USA TODAY, 11 Feb. 2022

Instead of brushes and a commutator, a small circuit board coordinates the energy delivery to the windings. —Doug Mahoney, Popular Mechanics, 14 June 2021

Before Tesla, inventors had always designed electric motors so that the magnetic field of the stator was kept constant and the magnetic field in the rotor was changed by means of a commutator. —National Geographic, 27 Sep. 2019

While watching how a DC motor sparked during a demonstration in his physics class, Tesla suggested that the commutator (the rotating switch feeding electricity to the rotor in the motor) should be eliminated. —National Geographic, 27 Sep. 2019

Word History

First Known Use

1880, in the meaning defined at sense 1

Kids Definition

commutator

noun

com·​mu·​ta·​tor ˈkäm-yə-ˌtāt-ər 

: a device for reversing the direction of an electric current so that the alternating currents made in a dynamo are changed to direct current