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... DC Motors Faraday constructed the first motor. By coiling (copper) wire around a (iron) metal core a strong electromagnet can be made. When attached to an electrical source it will produce a strong magnetic field. To keep this electromagnet spinning in a magnetic field, the direction that the curren ...
... DC Motors Faraday constructed the first motor. By coiling (copper) wire around a (iron) metal core a strong electromagnet can be made. When attached to an electrical source it will produce a strong magnetic field. To keep this electromagnet spinning in a magnetic field, the direction that the curren ...
AC Generators I Notes
... maximum values. Phase sequence is important because it determines the direction of rotation of a connected motor. Positive phase sequence (ABC): ...
... maximum values. Phase sequence is important because it determines the direction of rotation of a connected motor. Positive phase sequence (ABC): ...
introduction - KFUPM Faculty List
... terminals of the armature coil. Fixed brushes of metal or carbon are held against the commutator as it revolves, connecting the coil electrically to external wires. As the armature turns, each brush is in contact alternately with the halves of the commutator, changing position at the moment when the ...
... terminals of the armature coil. Fixed brushes of metal or carbon are held against the commutator as it revolves, connecting the coil electrically to external wires. As the armature turns, each brush is in contact alternately with the halves of the commutator, changing position at the moment when the ...
SPH 4A - mackenziekim
... 1. From where does the word magnet originate? 2. Draw domains in a highly magnetic bar of steel. Describe the domain theory and how it is used to explain what is created when a bar magnet is broken in half. 3. Sketch the pattern of the magnetic field around: a) a bar magnet b) an electromagnet 4. Wh ...
... 1. From where does the word magnet originate? 2. Draw domains in a highly magnetic bar of steel. Describe the domain theory and how it is used to explain what is created when a bar magnet is broken in half. 3. Sketch the pattern of the magnetic field around: a) a bar magnet b) an electromagnet 4. Wh ...
Chapter 4: DC Generators
... – voltage between the two segments is picked up by the brushes – the voltage between brushes x and y pulsate but never change polarity – the commutator acts as a mechanical reversing switch – the alternating voltage in the coil is rectified by the commutator – the constant polarity between x and y c ...
... – voltage between the two segments is picked up by the brushes – the voltage between brushes x and y pulsate but never change polarity – the commutator acts as a mechanical reversing switch – the alternating voltage in the coil is rectified by the commutator – the constant polarity between x and y c ...
Electric Machines ELCT708 Assignment # 3
... d. Induced torque at full load e. Starting induced torque f. Shaft torque g. Motor efficiency 2) A three-phase 125 hp, 440 V, 60 Hz, 8 poles, Y connected squirrel cage induction motor has the following equivalent per phase circuit parameters referred to primary: R1 = 0.068 , R2 = 0.052 , X1 = X2 = ...
... d. Induced torque at full load e. Starting induced torque f. Shaft torque g. Motor efficiency 2) A three-phase 125 hp, 440 V, 60 Hz, 8 poles, Y connected squirrel cage induction motor has the following equivalent per phase circuit parameters referred to primary: R1 = 0.068 , R2 = 0.052 , X1 = X2 = ...
GENERATOR AND MOTORS
... repel. All electric motors operate on this principle. Faraday constructed the first motor. By coiling (copper) wire around a (iron) metal core a strong electromagnet can be made. When attached to an electrical source it will produce a strong magnetic field. To keep this electromagnet spinning in a m ...
... repel. All electric motors operate on this principle. Faraday constructed the first motor. By coiling (copper) wire around a (iron) metal core a strong electromagnet can be made. When attached to an electrical source it will produce a strong magnetic field. To keep this electromagnet spinning in a m ...
The Rules of Electromagnetism
... current every half-revolution to ensure that the torque exerted on the armature continues to act in the forward direction. The sparking from the reversal of the current as well as the sliding contact causes wear of the brushes and commutator, which is a significant drawback of d.c. motors. The field ...
... current every half-revolution to ensure that the torque exerted on the armature continues to act in the forward direction. The sparking from the reversal of the current as well as the sliding contact causes wear of the brushes and commutator, which is a significant drawback of d.c. motors. The field ...
Two-Pole Brushless DC Motor with Three
... This is in the reality a permanent-magnet synchronous machine. It is named DC not because of its structure but due to the fact that its operating characteristics resemble those of a shunt DC motor with constant field current. This characteristic can be obtained by providing the motor with a power su ...
... This is in the reality a permanent-magnet synchronous machine. It is named DC not because of its structure but due to the fact that its operating characteristics resemble those of a shunt DC motor with constant field current. This characteristic can be obtained by providing the motor with a power su ...
Carbon brushes for fractional and subfractional horsepower motors
... roughening of the commutator surface, caused by commutator sparking, is kept within a normal range. This guarantees a longer life of the carbon brush. On the other hand the carbon brushes must not be too abrasive, so that the wear on the commutator remains minimal. It is therefore necessary to optim ...
... roughening of the commutator surface, caused by commutator sparking, is kept within a normal range. This guarantees a longer life of the carbon brush. On the other hand the carbon brushes must not be too abrasive, so that the wear on the commutator remains minimal. It is therefore necessary to optim ...
t6_generators
... In figure (1), each end of the rotating loop is attached to a metal hoop called a slip ring. The slip rings turn with the loop, but as they turn they rub against two electrical brush contacts. The brushes are fixed and carry the current produced in the rotating loop into the external circuit. This a ...
... In figure (1), each end of the rotating loop is attached to a metal hoop called a slip ring. The slip rings turn with the loop, but as they turn they rub against two electrical brush contacts. The brushes are fixed and carry the current produced in the rotating loop into the external circuit. This a ...
DO PHYSICS ONLINE MOTORS AND GENERATORS
... In figure (1), each end of the rotating loop is attached to a metal hoop called a slip ring. The slip rings turn with the loop, but as they turn they rub against two electrical brush contacts. The brushes are fixed and carry the current produced in the rotating loop into the external circuit. This a ...
... In figure (1), each end of the rotating loop is attached to a metal hoop called a slip ring. The slip rings turn with the loop, but as they turn they rub against two electrical brush contacts. The brushes are fixed and carry the current produced in the rotating loop into the external circuit. This a ...
• - No Brain Too Small
... The direction of the current can be found from Fleming's Right-hand Rule. (the lefthand rule is used for motors and motion produced by a magnetic field). The right-hand rule is used for generators and current generated by a motion. Using the right-hand, the thumb is in the direction of the motion, t ...
... The direction of the current can be found from Fleming's Right-hand Rule. (the lefthand rule is used for motors and motion produced by a magnetic field). The right-hand rule is used for generators and current generated by a motion. Using the right-hand, the thumb is in the direction of the motion, t ...
Commutator (electric)
![](https://commons.wikimedia.org/wiki/Special:FilePath/Universal_motor_commutator.jpg?width=300)
A commutator is the moving part of 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. It consists of a cylinder composed of multiple metal contact segments on the rotating armature of the machine. The commutator is one component of a motor; there are also two or more stationary electrical contacts called ""brushes"" made of a soft conductor like carbon press against the commutator, making sliding contact with successive segments of the commutator as it rotates. The windings (coils of wire) on the armature are connected to the commutator segments. Commutators are used in direct current (DC) machines: dynamos (DC generators) and many DC motors as well as universal motors. In a motor the commutator applies electric current to the windings. By reversing the current direction in the rotating windings each half turn, a steady rotating force (torque) is produced. 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. The first direct current commutator-type machine, the dynamo, was built by Hippolyte Pixii in 1832, based on a suggestion by André-Marie Ampère. Commutators are relatively inefficient, and also require periodic maintenance such as brush replacement. Therefore, commutated machines are declining in use, being replaced by alternating current (AC) machines, and in recent years by brushless DC motors which use semiconductor switches.