An important part of the armature of DC motors and AC commutator motors. When the motor rotates, it acts as a commutation. DC motor, AC series motor as the current commutation, in order to enable the motor to continue turning a part, commonly known as commutator.
As an important basic equipment for industry, transportation, national defense and daily life, the downstream industry contains almost all of the national economy-based industries. The commutator, as one of the core components of the motor, is also accompanied by the growing development of the motor industry.

The direct current is converted into a low frequency square wave to supply the power supply electrode, and the square wave signal measured by the measurement electrode is converted into a pulsating direct current device.

Mechanical commutators are used in multiline logging tools. Adjustable frequency 8 ~ 23Hz. Moreover, the commutator of the measurement circuit is turned off and turned on earlier than the commutator of the power supply line to reduce the induced interference caused by the change of the front and rear edges of the low-frequency square wave in the measurement circuit.

In addition, there are electronic commutators that use wet reeds. No matter what type of commutator is used, indirect fire extinguishing circuits are used to protect the contacts and reduce the interference on the measuring track.