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Feb 24, 2012 · Commutation in a DC machine, especially in a DC generator, is the process that converts this alternating current into direct current using the commutator and stationary brushes. In a DC Motor, the input direct current (DC) is converted to an alternating current (AC) in the armature through commutation. This transformation of current from the ...
A commutator is a rotary electrical switch in certain types of electric motors and electrical generators that periodically reverses the current direction between the rotor and the external circuit. It consists of a cylinder composed of multiple metal contact segments on the rotating armature of the machine.
Oct 26, 2023 · Motor commutators are utilized in different types of motors based on the requirement: Direct Current (DC) Motors: In DC motors, the commutator is an integral part, as it helps to switch the direction of the current, thereby ensuring that the motor rotates continuously. It serves as a mechanical rectifier to convert the alternating current in ...
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As the armature starts rotating, the brushes move over commutator segments. Let the first position of the brush commutator contact be at b as shown in the figure. As the width of the commutator and the brush is equal, the whole of the commutator segment and the whole of the brush is in contact with each other. The total current conducted by the com...
As the armature rotates towards the right, the brush comes in contact with the commutator bar a. At this position, the total current is 2Ia. The current in the coil changes as the current flows through two paths A and B. 3/4th of the 2Ia comes from the coil B and remaining 1/4th comes from coil A. When KCL is applied to the segment a and b, the cur...
At this position, each half of the brush is in contact with segment a and segment b as shown in the figure. Using KCL we observe that the current in coil B will be zero.
In this position, one-fourth of the brush is in contact with segment b and three fourth with segment a as shown in the figure. The current drawn through coil B is – Ia/2. We notice that the current in coil B is reversed.
In this position, the brush is in full contact with segment a and the current from coil B is Ia but in reverse direction to the current direction of position 1.Thus, the commutation process is completed for segment b.
Jan 7, 2016 · Commutation is the process of switching the field in the armature windings to produce constant torque in one direction, and the commutator is a device connected to the armature, which enables this switching of current. The lever arm for the torque produced on the armature varies with the angle of the coil (cos α).
The commutator is a split ring of larger size with large number of splits (commutator segments). It is called a mechanical rectifier in generator and an inverter in motor. The connections to the commutator depends upon the type of armature windings. These are made of hard copper so as to withstand the brush forces which are placed upon the ...
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Commutator and Brushes on DC Motor. To keep the torque on a DC motor from reversing every time the coil moves through the plane perpendicular to the magnetic field, a split-ring device called a commutator is used to reverse the current at that point. The electrical contacts to the rotating ring are called "brushes" since copper brush contacts ...
