Mell 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. Reason is…. The commutator alternates the current in conductor in armature.
What will happen if commutator is not used in 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.
What is a DC generator without commutator?
A D.C. generator without commutator is a AC generator.
Why are brushes used in DC motor?
They can either be graphite or precious metal brushes which have electrical motor connections. To supply power to the rotor we put in place a brush system and each of the brushes have a direct voltage symbol (+/-). The brushes are connected to the commutator bars which allows the current to flow into the winding.
What is OCC in DC generator?
Open Circuit Characteristic (O.C.C.) (E0/If) Open circuit characteristic is also known as magnetic characteristic or no-load saturation characteristic. This characteristic shows the relation between generated emf at no load (E0) and the field current (If) at a given fixed speed.
How does the commutation in a DC generator work?
The commutation in DC machine or more specifically commutation in DC generator is the process in which generated alternating current in the armature winding of a dc machine is converted into direct current after going through the commutator and the stationary brushes. Again in DC Motor, the input DC is to be converted in alternating form in
What happens if a commutator is not used in a DC motor?
If the motor uses a commutator to carry current to the armature, one thing will happen for sure – the motor won’t work. That’s like asking what will happen if I disconnect the motor in my car. The armature will align itself with the magnetic poles of the main field and remain stationary.
When do you use a commutator and a brush?
Commutator and Brushes Commutators and brushes are used on all DC generators and DC motors. They are also used on some AC motors such as the repulsion, synchronous, and universal motors. All generators produce a sine wave, or AC currents when the rotor turns in the magnetic field.
How does the current change in a commutator?
The current in the coil changes as the current flows through two paths A and B. 3/4th of the 2I a comes from the coil B and remaining 1/4th comes from coil A. When KCL is applied to the segment a and b, the current through coil B is reduced to I a /2 and the current drawn through segment a is Ia/2.