DC Motors – All That You Need To Know

Berlin, Germany, 2019-Jul-18 — /EPR Network/ — DC motors are electrically powered with the help of direct current (DC). It could be from a battery source or DC power supply. Their commutation can be either brushed or brushless. In that of a brushed DC motor, its speed can be controlled by only changing the voltage. One different factor is that an AC motor is powered by alternating current (AC), defined by both an energy and a frequency. As a result, engines powered by AC require a change in rate to change speed, involving more dynamic and costly speed control. This renders DC motors best used in equipment ranging from 12VDC systems in automobiles to conveyor motors. Both need excellent speed control ranging from speeds above and below the rated speeds. As an industrial buyer, before committing yourself to a DC motor, there is a need in identifying key performance specifications, determine design and size requirements. At the same time, considering the environmental implications of their tasks. The below will assist you in this selection process.

 Performance Specifications

The most important aspects to consider for DC motors are speed, performance, and operating voltage. Datasheets provided by suppliers list these three as the most basic.

Application Requirements

Just like any industrial buyer, it is vital to compare and contrast what is listed on a DC motor’s datasheet, to your application requirements. The reason for this is, the motor’s output parameters are interdependent, and thus a Global Spec user may define one or two specifications. The other will significantly rely upon the specs below.

Shaft Speed

DC motors use a voltage (V) in rotating a shaft at a proportional and rotational speed (ω). Shaft speeds specifications refer generally refer to the no-load speed. This is the maximum reached by the motor when no torque is applied. In a typical manner, the shaft speed is customarily given in rotations or revolutions per minute (rpm). These given revolutions can be related to the number of radians, expressed in radians per second (rad/s). In addition, as for numerical calculations, this unit of rotational speed is more convenient. The following formula thus best describes the relationship between radians per second and rotations or revolutions per minute.

Output Torque

In the DC Motor, shaft rotation generates a rotational force called torque (τ). This is translated as the load that can be produced or handled by the engine. Hence, the formula representing torque is given in force-distance units (lb-ft, oz-in, N-m, etc.). Torque specifications frequently refer to the stall torque and the continuous torque. Stall torque is represented by the symbol τ, when the shaft speed is zero, or when the motor stalls, while constant torque is the maximum represented by the symbol τ, when running conditions are normal. It is also worth noting that the torque (τ) of a DC motor is proportionate to the armature current (I), while the constant of proportionality is the torque constant. A high value of k is capable of limiting the current to a low cost, for a given torque. This is translated into a measure of efficiency since when the current consumption is small, it then means that there is a low transmission of power.

 

Please Visit http://www.power-tronic.com/ for more information.

Media Contact:

Powertronic Drive Systems GmbH

Hartmannstr, Berlin, Germany  12207

Phone: +49 30 7719635

powertronic24@rediffmail.com