Single Phase Motors
... field and the motor will develop a net positive torque in the same direction as the initial rotation. o Thus the motor will keep running in the direction of initial rotation. o According to this theory, any alternating quantity can be resolved into two rotating components which rotate in opposite di ...
... field and the motor will develop a net positive torque in the same direction as the initial rotation. o Thus the motor will keep running in the direction of initial rotation. o According to this theory, any alternating quantity can be resolved into two rotating components which rotate in opposite di ...
AC motors
... wound for as many numbers of poles as the stator. The three phases are wired internally and the other ends are connected to slip-rings mounted on a shaft with brushes resting on them. ...
... wound for as many numbers of poles as the stator. The three phases are wired internally and the other ends are connected to slip-rings mounted on a shaft with brushes resting on them. ...
Pre-Lab
... electromagnetic torque, the stator and rotor magnetic axes are displaced by 90 electrical degrees using commutator. Expression (5.3) for the electromagnetic torque Te Lsr isir sin r indicates that Te can be developed only if there exists a displacement between the armature (rotor) and fields (s ...
... electromagnetic torque, the stator and rotor magnetic axes are displaced by 90 electrical degrees using commutator. Expression (5.3) for the electromagnetic torque Te Lsr isir sin r indicates that Te can be developed only if there exists a displacement between the armature (rotor) and fields (s ...
model test ( sem-iii)
... B. motor running above the normal rated speed C. applied voltage is very low D. grounded field due to weak insulation and poor earthing. 22. Motor gives humming noise when running ...
... B. motor running above the normal rated speed C. applied voltage is very low D. grounded field due to weak insulation and poor earthing. 22. Motor gives humming noise when running ...
E a
... Voltage across armature can be controlled by adding a variable resistance in series with the armature Potential divider control : If the speed control from zero to the rated speed is required , by rheostatic method then the voltage across the armature can be varied by connecting rheostat in a ...
... Voltage across armature can be controlled by adding a variable resistance in series with the armature Potential divider control : If the speed control from zero to the rated speed is required , by rheostatic method then the voltage across the armature can be varied by connecting rheostat in a ...
Construction of a simple motor
... be a turning force induced. It forces the wire to rotate at the direction of the arrow in Figure 2. However after a half turn, the turning force would be reversed as shown in Figure 3. So some techniques have to be used to change direction of current flow in coil, or just block the current flow in t ...
... be a turning force induced. It forces the wire to rotate at the direction of the arrow in Figure 2. However after a half turn, the turning force would be reversed as shown in Figure 3. So some techniques have to be used to change direction of current flow in coil, or just block the current flow in t ...
DC Motor Workshop
... and these coils have been rotated 90° towards your line of sight. Follow the direction of the positive current, which enters the commutator on the right and then splits, with part going into the lower coil and the rest into the upper right coil (the brushes are not shown). These two currents recombi ...
... and these coils have been rotated 90° towards your line of sight. Follow the direction of the positive current, which enters the commutator on the right and then splits, with part going into the lower coil and the rest into the upper right coil (the brushes are not shown). These two currents recombi ...
ET 6 - Marine Engineering Study Materials
... 1. The e.m.f. generated in a coil on an alternator is 20V. Calculate the e.m.f. between the ends of two such coils, connected in series, if they are separated on the alternator core by 30 electrical degrees. 2. A six-pole, 50Hz, three-phase, wound-rotor induction motor running on full load develops ...
... 1. The e.m.f. generated in a coil on an alternator is 20V. Calculate the e.m.f. between the ends of two such coils, connected in series, if they are separated on the alternator core by 30 electrical degrees. 2. A six-pole, 50Hz, three-phase, wound-rotor induction motor running on full load develops ...
Massachusetts Institute of Technology Department of Electrical
... machines have not reached application and are not likely to. In the machines we have examined so far the machine is operated from an alternating voltage source. Indeed, this is one of the principal reasons for employing AC in power systems. The first electric machines employed a mechanical switch, i ...
... machines have not reached application and are not likely to. In the machines we have examined so far the machine is operated from an alternating voltage source. Indeed, this is one of the principal reasons for employing AC in power systems. The first electric machines employed a mechanical switch, i ...
electric motors
... overloading. Built-in thermal protective devices may be of either the automatic-reset type or manual-reset type. A manual-reset type is recommended for general purpose use. An automatic-reset type protective device should not be used on any motor where automatic restarting of the motor could cause a ...
... overloading. Built-in thermal protective devices may be of either the automatic-reset type or manual-reset type. A manual-reset type is recommended for general purpose use. An automatic-reset type protective device should not be used on any motor where automatic restarting of the motor could cause a ...
Budgeting - Learning While Doing
... Induction Motor • Most AC motors are induction motors • Induction motors are favored due to their ruggedness (no brush), simplicity and cheap. • 90% of industrial motors are induction motor. ...
... Induction Motor • Most AC motors are induction motors • Induction motors are favored due to their ruggedness (no brush), simplicity and cheap. • 90% of industrial motors are induction motor. ...
article: Brushed DC electric motor
... circuit or field circuit allowed speed control. Modern DC motors are often controlled by power electronics systems called DC drives. The introduction of DC motors to run machinery eliminated the need for local steam or internal combustion engines, and line shaft drive systems. DC motors can operate ...
... circuit or field circuit allowed speed control. Modern DC motors are often controlled by power electronics systems called DC drives. The introduction of DC motors to run machinery eliminated the need for local steam or internal combustion engines, and line shaft drive systems. DC motors can operate ...
How Electric Motors Work
... Now say that you take your nail electromagnet, run an axle through the middle of it and suspend it in the middle of a horseshoe magnet as shown in the figure below. If you were to attach a battery to the electromagnet so that the north end of the nail appeared as shown, the basic law of magnetism te ...
... Now say that you take your nail electromagnet, run an axle through the middle of it and suspend it in the middle of a horseshoe magnet as shown in the figure below. If you were to attach a battery to the electromagnet so that the north end of the nail appeared as shown, the basic law of magnetism te ...
Technical Data - Ordering Data - MD 24-28
... • 15 (14)* selectable resolutions up to 25,600 steps/rev (51,200 steps/rev)* • Opto-isolated, TTL-compatible inputs • Protection against short-circuit, overvoltage and overcurrent* * MD 28 ...
... • 15 (14)* selectable resolutions up to 25,600 steps/rev (51,200 steps/rev)* • Opto-isolated, TTL-compatible inputs • Protection against short-circuit, overvoltage and overcurrent* * MD 28 ...
In a typical DC motor, there are permanent magnets on the outside
... is equal to the synchronous speed, the slip ratio is 1, and the induced emf in the rotor is large. As a result, a very high current flows through the rotor. This is similar to a transformer with the secondary coil short circuited, which causes the primary coil to draw a high current from the mains. ...
... is equal to the synchronous speed, the slip ratio is 1, and the induced emf in the rotor is large. As a result, a very high current flows through the rotor. This is similar to a transformer with the secondary coil short circuited, which causes the primary coil to draw a high current from the mains. ...
Electromagnetism Quiz
... 4. The direction of the field described in question 2 depends on the current’s a) voltage. b) resistance. c) direction. d) none of the above ...
... 4. The direction of the field described in question 2 depends on the current’s a) voltage. b) resistance. c) direction. d) none of the above ...
Commutator (electric)
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.