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A DC armature of a miniature motor (or generator) An example of a triple-T armature A partially-constructed DC armature, showing the (incomplete) windings. In electrical engineering, the armature is the winding (or set of windings) of an electric machine which carries alternating current. [1]
For a single armature winding, when the shaft has made one-half complete turn, the winding is now connected so that current flows through it in the opposite of the initial direction. In a motor, the armature current causes the fixed magnetic field to exert a rotational force, or a torque , on the winding to make it turn.
The stator consists of field windings while the rotor (also called the armature) consists of an armature winding. [4] When both the armature and the field windings are excited by a DC supply, current flows through the windings and a magnetic flux proportional to the current is produced. When the flux from the field interacts with the flux from ...
The DC motor's input voltage must overcome the counter emf as well as the voltage drop created by the armature current across the motor resistance, that is, the combined resistance across the brushes, armature winding and series field winding, if any: V m = E b + R m I a [8] [9]
Today DC motors are still found in applications as small as toys and disk drives, or in large sizes to operate steel rolling mills and paper machines. Large DC motors with separately excited fields were generally used with winder drives for mine hoists, for high torque as well as smooth speed control using thyristor drives. These are now ...
where is the armature current of the machine (SI unit: ampere). is primarily used to calculate the armature current for a given torque demand: = The SI units for the torque constant are newton meters per ampere (N·m/A).
Therefore, DC motor brush design entails a trade-off between output power, speed, and efficiency/wear. DC machines are defined as follows: [75] Armature circuit – A winding that carries the load, either stationary or rotating. Field circuit – A set of windings that produces a magnetic field.
A compensation winding in a DC shunt motor is a winding in the field pole face plate that carries armature current to reduce stator field distortion.Its purpose is to reduce brush arcing and erosion in DC motors that are operated with weak fields, variable heavy loads or reversing operation such as steel-mill motors.