Some parameters of DC motor you should know

As the executive component of the motor, the DC motor has a closed main magnetic circuit inside. The main magnetic flux flows in the magnetic circuit while interlinking with the second circuit. One magnetic circuit is used to generate magnetic flux, called the excitation circuit, and the other is used to transmit power, called the power loop or armature loop. The Current DC motors are all rotating armature type, that is to say, the magnetic pole stator composed of the exciting winding and the iron core surrounded by it, the armature winding with the commutation unit and the armature iron core are combined to form the rotor of the DC motor.


DC motor

1. Torque: the Torque at which the motor can rotate, in kg.m or N.m


2. Torque coefficient: the proportional coefficient of the Torque produced by the motor, which generally represents the magnitude of the Torque produced by the armature Current per ampere;


3. Friction Torque: Torque loss caused by friction in brushes, bearings, commutation units, etc.;


4. Starting Torque: the rotation Torque generated by the motor starting;


5. Rotation Speed: the Speed at which the motor rotates. The engineering unit is r/min, which means revolution per minute. In the international system of units, it is rad/s, which means arc per second;


6. Armature resistance: The internal resistance of the armature, in a brushed motor, generally includes the contact resistance between the brush and the commutator. Since the resistance will generate heat when Current flows, it is always hoped that the armature resistance should be as small as possible;


7. Armature inductance: Because the armature winding is composed of metal coils, there must be inductance. From the perspective of improving the performance of the motor, the smaller the armature inductance, the better;


8. Electrical time constant: The time it takes for the armature Current to reach 63.2% of the stable value from zero. When measuring the electric time constant, the motor should be in the state of blocking and applying the driving Voltage with step property. In electrical time constant engineering, resistance R A and inductance L A of armature winding are often used to find out:

T e = L a/ R a


9. Mechanical time constant: the time taken for the motor to reach 63.2% of No Load Speed at the beginning. When measuring the mechanical time constant, the electric motor should be in a No Load running state, and a step motor should be applied.


We believe that these parameters help you in choosing which motor is more convenient and efficient. Kinmore Motor provides you with the best driving scheme and customized services.

Read More

DC Motor

What is a DC motor?

When it comes to DC motor, no one knows it better than Kinmore motor, who always strives to develop, design, and manufacture micro precision DC motors. Here is a detailed introduction to what is DC motor.   Definition of a DC motor   A direct Current (DC) motor is a

Read More »
gear motor

The classification of gear motor

Being a transmission device that is used widely, the gear motor mainly consists of the drive motor and the reducer. According to the transmission structure and application fields, gear motor can be mainly divided into large-scale gear motor, mini gear motor, gear reduction motor, planetary gear motor, dc gear motor,

Read More »
brushless DC motors

How to power brushless DC motors

The brushless DC (BLDC) motor’s increasing popularity is due to the use of electronic communication. That replaces the conventional mechanics comprised of brushes rubbing on the commutator to energize the windings in the armature of a DC motor.

Read More »

Contact Form

Your message will be replied in 24 hours.

Personal Information
Product Inquiry
>> Attached Files