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Certain "Lap" wound armatures.
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∙ 11y ago
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What is equalizer bar ring in lap winding?
The function of equalizer rings is to avoid un equal distribution of current at the brushes,there by helping to get sparkless commutation- by rizwan ahmad
Why is stationary armature preffered you commercial generators than moving armature?
The problem with a generator having a rotating armature is that the armature must be connected to its external load via slip rings and brushes. As power station alternators generate voltages up to 25 kV or so, and supply hundreds of amperes, the resulting arcing at the slip rings would be severe, and would require short maintenance cycles. Accordingly, it makes more sense for the armature to be stationary, and connected directly to its load, and have the field winding rotate instead, because the voltage/current applied to the field winding is quite low.
What causes the electrical polarity of the armature to reverse?
poles of an armature can be reversed by the arrangement of split-rings
What is interpole in dc motors?
the armature current is brought thru the interpole winding near the brushes this shifts the electrical null to reduce arcing with heavy loads there were arrangements with small motors to shift the brush holder rings but the interpole has no moving parts and works under all loading conditions
Operation of DC generator?
1) PRINCIPLE:Whenever a conductor cuts magnetic flux, dynamically induced emf is produced in it. ( Faraday's Laws of Electromagnetic Induction ). This emf causes a current to flow if the conductor circuit is closed.2 ) OPERATION:Field winding produces magnetic field in D.C. generator. Armature is coupled to the prime mover. Prime mover produces torque so the armature rotates. The armature cuts the magnetic field so the emf is induced in the armature. When load is connected to the armature, electric current flows from the armature conductors, through load and back to the armature conductors. Now, as current flows through the armature and it is in the magnetic field, torque is produced due to it. (This torque is called back torque). If the load on the generator is increased, the back torque increases so the torque of the prime mover also increases and the input power to the prime mover increases. In this way, the generator converts mechanical energy into electrical energy.It should be observed that the emf induced in D.C. generator, is A.C. ( so the emf induced in the armature is alternating in nature. ). Then with the help of commutator, it is converted into D.C. Rings and brushes are used to take the emf outside.
What is equalizer bar ring in lap winding?
The function of equalizer rings is to avoid un equal distribution of current at the brushes,there by helping to get sparkless commutation- by rizwan ahmad
Why is stationary armature preffered you commercial generators than moving armature?
The problem with a generator having a rotating armature is that the armature must be connected to its external load via slip rings and brushes. As power station alternators generate voltages up to 25 kV or so, and supply hundreds of amperes, the resulting arcing at the slip rings would be severe, and would require short maintenance cycles. Accordingly, it makes more sense for the armature to be stationary, and connected directly to its load, and have the field winding rotate instead, because the voltage/current applied to the field winding is quite low.
Why field winding work as stator and armature winding as rotor?
No, these can be switched depending on the requirements of the application. It is more practical to have the armature windings (since they will carry the full load current) as the stator for this will require larger wires and is also easier to cool if kept stationary. The field windings do not carry the full load current of the load so this requires smaller wires and smaller slip rings since this is the piece that will rotate.
What causes the electrical polarity of the armature to reverse?
poles of an armature can be reversed by the arrangement of split-rings
What is the function of slip rings in ac generator?
They rotate the armature coil.
Why armature is static and field is rotating in alternator?
It is a more convenient arrangement because it does not need a commutator. The rotor is fed with DC through slip-rings and the brushes last much longer. The main current is generated in the static winding enclosing the rotor.
Why are the slip rings needed in dc motor?
Slip rings are needed to connect a rotating armature to external fixed circuits.
What is interpole in dc motors?
the armature current is brought thru the interpole winding near the brushes this shifts the electrical null to reduce arcing with heavy loads there were arrangements with small motors to shift the brush holder rings but the interpole has no moving parts and works under all loading conditions
What is the need for slip rings?
Slip rings offer a means of connecting a rotating winding to an external circuit. Slip rings are used when an a.c. output is desired.
What is the function of the commutator on the armature?
A commutator is used to interconnect the rotor winding to the outside world (it doesn't connect to the armature/stator winding). It's similar to slip rings, although much more complex. It switches current direction as the rotor spins so a constant DC is applied to the rotor field winding.AnswerA commutator....(a) enables a rotating machine to be electrically connected to an external load.(b) is a rotary switch, which acts to rectify the a.c. voltage which is naturally generated in any rotating machine, to provide a d.c. voltage output.
State the important difference between a transformer and induction motor?
A transformer uses a varying magnetic field to induce a voltage in another winding, often changing the voltage to match the requirements of the load.A motor uses a varying magnetic field in induce a torque in the armature, making it turn, converting electrical energy into mechanical energy. In the case of an induction motor, the "windings" in the armature are built in as "single turn shorted secondary windings", rather than windings connected via slip rings or commutators, but the end result is the same - opposing and attracting magnetic fields cause the armature to rotate.
Operation of DC generator?
1) PRINCIPLE:Whenever a conductor cuts magnetic flux, dynamically induced emf is produced in it. ( Faraday's Laws of Electromagnetic Induction ). This emf causes a current to flow if the conductor circuit is closed.2 ) OPERATION:Field winding produces magnetic field in D.C. generator. Armature is coupled to the prime mover. Prime mover produces torque so the armature rotates. The armature cuts the magnetic field so the emf is induced in the armature. When load is connected to the armature, electric current flows from the armature conductors, through load and back to the armature conductors. Now, as current flows through the armature and it is in the magnetic field, torque is produced due to it. (This torque is called back torque). If the load on the generator is increased, the back torque increases so the torque of the prime mover also increases and the input power to the prime mover increases. In this way, the generator converts mechanical energy into electrical energy.It should be observed that the emf induced in D.C. generator, is A.C. ( so the emf induced in the armature is alternating in nature. ). Then with the help of commutator, it is converted into D.C. Rings and brushes are used to take the emf outside.
