75 Segments Commutator Mechanical Commutator For Various Motors
The functions of the commutator is given below:
- To facilitate the collection of current from the armature
- To convert internally developed alternating EMF to unidirectional
- To produce unidirectional torque in case of motors.
- The commutator is of cylindrical shape.
- It is made up of wedge-shaped copper segments of high conductivity.
- They are insulated from each other by a thin sheet of mica.
- Each segment is connected to armature conductors by means of a
copper strip( which is known as riser).
Mechanical Commutator Vs Electronic Commutator:
|Mechanical Commutator||Electronic Commutator|
|It is made up of commutator segments and mica insulation. Brushes
are made up of carbon or graphite.||Power Electronic switching devices are used in the commutator.|
|Commutator arrangement is located in the rotor.||Commutator arrangement is located in the stator.|
|Shaft position sensing is inherent in the arrangement.||It requires a separate rotor position sensor.|
|Number of commutator segments are very high.||Number of switching devices is limited to 6.|
|Sliding contact between commutator and brushes.||No sliding contacts.|
|Sparking takes place.||There is no sparking.|
|It requires a regular maintenance.||It requires less maintenance.|
|Difficult to control the voltage available across tappings.||Voltage available across armature tappings can be controlled by PWM
|Highly reliable.||Reliability can be improved by specially designed devices and