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The field current of a dc motor provides the magnetic field that allows the motor to develop a torque when current flows through the armature..
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How speed increases when flux decreases in dc shunt motor?
Increasing flux, torque of the dc motor will be increased and speed of the dc motor will be decreased as speed of the dc motor is inversely proportional to that of the flux and the torque of the dc motor is directly proportional to the flux.
If the speed of the dc shunt motor falls due to loading what will be the effect?
on adding load on a dc shunt motor, the amount of current and torque will increase. but terminal voltage will decrease
What can change an ac current to a DC current?
rectifierac motor - dc generator set
What is the difference between field current and voltage?
Field Current in a DC Motor is the flow of electrons through the field circuit by a field controller. The flux of the motor, that with the armature current generates torque, is directly proportional to the field current. Field Voltage is the electrical potential energy applied on the field circuit by a field controller. Legacy Field Controllers controlled the field voltage. Using I=V/Z (Z=R+iX) the field current is then indirectly controlled. Due to the heat generated by E=i2 R t in the motor, the resistance R would decrease, increasing the field current and therefore changing the base speed of the motor and disturbing the control. Newer field controllers control the field current eliminating this problem
Does a induction motor need excitation?
The induction motor is the special kind of motor which runs below and above the synchronous speed. which the synchronous motor runs nearly equal the synchronous speed. The operation of synchronous motor runs with dc field excited hence separate dc field current is given to the field circuit. where as the induction motor the field and main field is drawn from the same supply hence no excitation is required. But due to this separate starting mechanism has to be required in case of the single phase induction motor.
What is armature reaction in dc machines?
The armature reaction is the interaction between armature flux and field flux when current is introduced to a dc motor. It results in a cross-magnetizing effect and a demagnetizing effect.
What role does the armature do in a DC motor?
One of the role of the armature in the DC motor is to carry the current that is crossing the field. By carrying the current crossing the field, it creates the shaft torque in the rotating machine.
Why dc supply is being used in studying the effect of temperature on the field winding resistance of a dc motor?
Because tests on a dc motor are always done using dc.
How speed increases when flux decreases in dc shunt motor?
Increasing flux, torque of the dc motor will be increased and speed of the dc motor will be decreased as speed of the dc motor is inversely proportional to that of the flux and the torque of the dc motor is directly proportional to the flux.
Is the torque output of a DC motor directly proportional to armature current?
In dc shunt motor,base speed is 500 rpm and its field current is 17A, top speed is 1200 rpm and field current is 5.6 A.But 600 rpm it has reduced by 10A It is normal? How
What is back motor effect in generator?
When current is induced in the rotating coil in an electric generator then a counter couple acts on the current carrying rotating coil in the magnetic field(in accordance to the principle of dc motor). This counter couple is called back motor effect.
Why current is supplied to DC motor?
What supplies a dc motor is not current, but voltage. Current is what flows in the circuit formed by the dc motor and for the charge. That current varies according to the resistance of the circuit.
What field setting for a dc shunt motor wired in series on high voltage?
A shunt dc motor has quite different characteristics from a series motor. Wired in series, the same current passes through the armature and the field winding and it is most unlikely that a shunt motor would have a field winding that is suitable for this. Therefore a shunt motor cannot be wired as a series motor in general because its field winding is designed for only a small current.
What is the purpose of the fields of a dc shunt motor?
DC Shunt motor: dc shunt motor is a motor with dc supply given to the inductor connected in parallel with the armature of a motor. The inductor connected in parallel with the armature of a motor called field winding of a motor.In dc shunt motor: When current flows through a conductor ( here it is armature in case of dc shunt motor ), magnetic field is produced which is circular and when this conductor is placed perpendicular in the magnetic field ( which is produced by the current or say dc supply that given to the inductor or say field winding of the dc shunt motor ), the main magnetic lines get bent due to the interaction of the two fields. These lines of force experience tension and try to become straight. So, a force is produced on the conductor ( armature ), due to which the conductor ( armature ) will rotates. The direction of force can be found by Fleming's right hand rule.Main Answer: Thus, it should be understood that field winding in dc shunt motor stands to get interaction of the two field in such a way that force is produced on the armature so that the armature get to rotate.Some Facts: Actually the current in armature is due to the mutual induction by field winding to the armature. That means only field winding get dc supply through which current and so magnetic field is produced in armature that try to oppose due which it is produced, that means it oppose the main magnetic field of field winding.
If the speed of the dc shunt motor falls due to loading what will be the effect?
on adding load on a dc shunt motor, the amount of current and torque will increase. but terminal voltage will decrease
What is the dc motor?
Almost all the electro-mechanical movements we see around us are caused either by an A.C. or a DC motor. Here we will be exploring this kind of motors. This is a device that converts DC electrical energy to a mechanical energy.Principle of DC MotorThis DC or direct current motor works on the principal, when a current carrying conductor is placed in a mgnetic field, it experiences a torque and has a tendency to move. This is known as motoring action. If the direction of current in the wire is reversed, the direction of rotation also reverses. When mgnetic field and electric field interact they produce a mechanical force, and based on that the working principle of dc motor established.
Can you tell me The working of DC motor?
A DC motor works on the principle of Faraday's law of electromagnetic induction, i.e., when a current carrying conductor is placed in a magnetic field, it experiences a force applied on it.
