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How do you find the armature and field terminals in a dc motor without any indication in the name plate?
The Quickest easiest way is going to be with a battery or jumper pack. Ground the body and touch the two terminals one at a time with the positive lead from a battery or jumper pack. One makes it turn the other makes it stop, the one that makes it turn is the starter or armature, the one that does nothing is the field. To go one step further to see if you are getting a good generator start it to full rpm and remove from the armature terminal and quickly touch the field terminal if the charging part is working correctly it should forcibly stop the pulley from rotating, you will notice a difference from just letting it spin to a stop.
What else can I help you with?
What is Comparison of armature controlled and field controlled DC servo motor?
Difference between field controlled and armature controlled is that field control is open loop and armature current is closed loop.
Why the armature voltage E changes when the field rheostat is varied in shunt motors?
In shunt motors, the armature voltage ( E ) changes when the field rheostat is varied because altering the resistance in the field circuit affects the field current and, consequently, the magnetic flux produced by the field winding. When the field rheostat is decreased, the field current increases, leading to a stronger magnetic field and a higher back electromotive force (EMF) generated in the armature. This results in a change in the armature voltage, as the increased back EMF reduces the net voltage across the armature. Conversely, increasing the field resistance weakens the magnetic field, reducing back EMF and allowing the armature voltage to rise.
Why armature winding resistance is less than field winding resistance?
An 'armature winding' is the rotor winding, and the 'field winding' is the stator winding.
What are the values of armature and field rheostat to be maintained during starting of a d.c motor?
you want full field while starting 0 Ohms and maximum series on armature then bring the armature resistance to zero as it approaches running speed its a good idea to run with armature at 0 ohms armature will use the same amount of power as the resistor If you want to run at more than base speed you can now weaken the field
What 3 factors that affect the output of a generator?
1:The strenght of the main magnetic Field. Determined by the strenght of the field magnets in a permanent magnet machine, or by the number of turns of wire on the field coils and the current through the coils in a wound field machine.2: The number of armature conductors connected in series, which cut the main magnetic field. Determined by the number of turns on armature coils and weather the armature is lap or wave wound, which determines the number of armature conductors connected in series.3: The speed at which the armature conductors cut the main magnetic field. The faster the armature cuts the magnetic Field, the higher will be the value of the voltage generated in the machine
If you were to mechanically rotate the armature in an electric motor what would happen?
You said "armature" so it is a dc motor. Hence if the field is permanent magnet type then a voltage appears at the armature terminals nd its magnitude depends on the speed nd magnetic field strength. If it's field coils, then they must be seperately excited (if it don't possess residual). By changing the field strength you can vary the voltage produced at armature terminals.
Why 3 point starter is called 3 point starter?
Because it has three terminals L , F and A L - Line (connected to Supply) F - Field (connected to field of dc motor) A - Armature (connected to armature of DC motor) that's y it is called 3 point starter :)
What is Comparison of armature controlled and field controlled DC servo motor?
Difference between field controlled and armature controlled is that field control is open loop and armature current is closed loop.
Why direction of rotation is not reversed when both field and armature terminals are reversed?
The direction of the force that drives the machine is determined by the relative directions of the field and the armature current. By reversing the direction of both field and the armature current, the direction of the resulting force stays the same; you have to reverse the direction of one or the other; not both! Prove it for yourself, by applying Fleming's Left-Hand Rule (for conventional current flow); reverse the direction of both your first finger (field) and your second finger (armature current), and you thumb (direction of motion) will end up pointing in the same direction!
What is mean by armature reaction?
armature reaction means when load is added to the armature then current is passed through armature conductors then in armature creates flux. It is demagnetize and cross magnetize the main field flux. in other ward it is effect of armature field on main field.
What is the function of field winding in DC generator?
The motor needs the current and magnetic flux to create motion The magnetic field is created by field winding where as armature carries the current resulting into the rotation of armature
How is a DC waveform produced from the output terminals of a DC generator?
A DC waveform is produced from the output terminals of a DC generator through the action of a commutator, which converts the alternating current induced in the armature windings into direct current by reversing the direction of current flow at the appropriate times. As the armature rotates within the magnetic field, the commutator ensures that the output current remains unidirectional, resulting in a DC waveform at the generator terminals.
What are the parts and its function of electric motor?
1. Armature coil 2. Field magnets 3. Split or Slip rings 4. Carbon or metallic brushes
Why the armature voltage E changes when the field rheostat is varied in shunt motors?
In shunt motors, the armature voltage ( E ) changes when the field rheostat is varied because altering the resistance in the field circuit affects the field current and, consequently, the magnetic flux produced by the field winding. When the field rheostat is decreased, the field current increases, leading to a stronger magnetic field and a higher back electromotive force (EMF) generated in the armature. This results in a change in the armature voltage, as the increased back EMF reduces the net voltage across the armature. Conversely, increasing the field resistance weakens the magnetic field, reducing back EMF and allowing the armature voltage to rise.
Why armature winding resistance is less than field winding resistance?
An 'armature winding' is the rotor winding, and the 'field winding' is the stator winding.
How do commutating field windings cope with the effect of armature reaction?
Commutating field windings are connected in series with the armature windings so that the current flowing in the coils is always equal to the armature current. The number of turns in the commutating field windings are also equal to the number of armature turns. This means that the field strength of the commutating windings and the field strength of the armature are always equal. A DC motor is constructed so that these two fields of equal strength oppose one another, they therefore cancel one another out. The main field is now unaffected by armature reaction.
What is the difference between armature reaction and armature reactance?
armature reactant means loss in armature associated with inductive properties of the coil, while armature reaction include losses due to magnetizing component of current flowing through armature.
