What is the purpose why DC generator has a commutator?
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What is the purpose why DC generator has a commutator?
The commutator on the DC generator converts the AC into pulsating DC. The commutator assures that the current from the generator always flows in one direction. The brushes ride on the commutator and make good electrical connections between the generator and the load.
Do DC generators have rectifiers?
Commutator in the rotor and associated brush assembly together is called mechanical rectifier. This arrangement, in DC generators, convert AC voltage generated in armature winding coils in rotor to DC voltage and current to the external circuit.
How does commutator act as rectifier?
In case of a commutator, the terminals are physically turned to make contact with the terminals of opposite polarity. This mechanical rotation is coupled with the electrical voltage. As soon as the direction of voltage changes, the commutator turns, reversing the polarity, and giving a rectified output.
Why commutator is not used in AC generator?
The main purpose of commutator is only to convert Ac to DC or vice versa, But in case of alternaters Commutator is not required because output will be AC only not DC. In case of DC generators Generation is AC so by using commutator will convert the AC to DC.
What are the function of commutator?
The function of commutator ring in an electric motor is to reverse the direction of current flowing through the coil every time coil just passes the vertical position during a revolution. Hence as the direction of the current is reversed, the torque is changed in the direction.
What will happen if commutator is not used in a DC motor?
Well, without commutator, the machine will not develop a unidirectional torque and motoring action will not take place. In a DC motor, at the instant when armature coil passes through magnetic neutral axis, current in armature coil must reverse to maintain torque in the same direction.
Is commutator a rectifier?
In a generator the commutator picks off the current generated in the windings, reversing the direction of the current with each half turn, serving as a mechanical rectifier to convert the alternating current from the windings to unidirectional direct current in the external load circuit.
Which part of DC generator is working as rectifier?
The best-known type is the commutator, which is an integral part of a DC dynamo, but before solid-state devices became available, independent mechanical rectifiers were used for certain applications. Before the invention of semiconductors, rectification at high currents involved serious losses.
Is a commutator a rectifier?
A rectifier are used in power supplies but commutators are used in d.c. generators and motors. A commutator is a rotating device whereas a rectifier is not. The rectified output from a commutator is fed to an external circuit whereas the rectifier is used in the output circuit.
Does an AC generator have a commutator?
AC generator does not have commutators. DC generators have commutators to make the current flow in one direction only. AC generators have slip-rings.
What happens when there is no commutator?
Without commutator it will not rotate and the armature oscillates between north and south poles. No motor action.
What is the function of commutator in electric motor?
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.