Chapter 6. Synchronous Machines
... variable speed drives. If the stator excitation of a permanent magnet motor is controlled by its rotor position such that the stator field is always 90o (electrical) ahead of the rotor, the motor performance can be very close to the conventional brushed dc motors, which is very much favored for vari ...
... variable speed drives. If the stator excitation of a permanent magnet motor is controlled by its rotor position such that the stator field is always 90o (electrical) ahead of the rotor, the motor performance can be very close to the conventional brushed dc motors, which is very much favored for vari ...
5magnetics - The Gravity Search
... each other out. It is often the case that the individual electrons in the solid will contribute magnetic forces that point in different, random directions, so that the material will not be magnetic. Sometimes owing to an applied external magnetic force each of the electron magnetic moments will be, ...
... each other out. It is often the case that the individual electrons in the solid will contribute magnetic forces that point in different, random directions, so that the material will not be magnetic. Sometimes owing to an applied external magnetic force each of the electron magnetic moments will be, ...
Example CF2: Export the field solution to a uniform grid
... Example CF3: Calculate the conduction current in a branch of a complex conduction path Description: There are situations where the current splits along the conduction path. If the nature of the problem is such that symmetry considerations cannot be applied, it may be necessary to evaluate total curr ...
... Example CF3: Calculate the conduction current in a branch of a complex conduction path Description: There are situations where the current splits along the conduction path. If the nature of the problem is such that symmetry considerations cannot be applied, it may be necessary to evaluate total curr ...
MAGNETICALLY INDUCED EMF
... - Similarity to motor Despite its simplicity, the moving metal rod in Fig. A-2 illustrates all the basic principles involved in practical generators. For example, the arrangement shown in Fig. A-2b is quite similar to that of the very simple motor illustrated in Figure (G-1) of Unit 426. In both cas ...
... - Similarity to motor Despite its simplicity, the moving metal rod in Fig. A-2 illustrates all the basic principles involved in practical generators. For example, the arrangement shown in Fig. A-2b is quite similar to that of the very simple motor illustrated in Figure (G-1) of Unit 426. In both cas ...
High-Temperature Superconductivity
... Thus, the Ginzburg–Landau (GL) parameter ¼ = is large, and the high-temperature superconductors are then said to be ‘‘extreme type II superconductors’’. e) The superconductivity wave function has d-wave symmetry in high-temperature superconductors; on the other hand, that of low temperature supe ...
... Thus, the Ginzburg–Landau (GL) parameter ¼ = is large, and the high-temperature superconductors are then said to be ‘‘extreme type II superconductors’’. e) The superconductivity wave function has d-wave symmetry in high-temperature superconductors; on the other hand, that of low temperature supe ...
Document
... where | E |mis the amplitude of the field intensity of the directional antenna in the direction for maximum radiation, and | E 0 | is the amplitude of the field intensity of the omnidirectional antenna. Obviously, Pr Pr 0 and D 1. The sharper the directivity is, the greater the directivity coeff ...
... where | E |mis the amplitude of the field intensity of the directional antenna in the direction for maximum radiation, and | E 0 | is the amplitude of the field intensity of the omnidirectional antenna. Obviously, Pr Pr 0 and D 1. The sharper the directivity is, the greater the directivity coeff ...
Phys. Rev
... M. P. Gelfand, R. R. P. Singh, and D. A. Huse, Phys. Rev. B 40, 10801-10809 (1989). N. Katoh and M. Imada, J. Phys. Soc. Jpn. 63, 4529 (1994). J. Tworzydlo, O. Y. Osman, C. N. A. van Duin, J. Zaanen, Phys. Rev. B 59, 115 (1999). M. Matsumoto, C. Yasuda, S. Todo, and H. Takayama, Phys. Rev. B 65, 014 ...
... M. P. Gelfand, R. R. P. Singh, and D. A. Huse, Phys. Rev. B 40, 10801-10809 (1989). N. Katoh and M. Imada, J. Phys. Soc. Jpn. 63, 4529 (1994). J. Tworzydlo, O. Y. Osman, C. N. A. van Duin, J. Zaanen, Phys. Rev. B 59, 115 (1999). M. Matsumoto, C. Yasuda, S. Todo, and H. Takayama, Phys. Rev. B 65, 014 ...
Electromagnet
An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. The magnetic field disappears when the current is turned off. Electromagnets usually consist of a large number of closely spaced turns of wire that create the magnetic field. The wire turns are often wound around a magnetic core made from a ferromagnetic or ferrimagnetic material such as iron; the magnetic core concentrates the magnetic flux and makes a more powerful magnet.The main advantage of an electromagnet over a permanent magnet is that the magnetic field can be quickly changed by controlling the amount of electric current in the winding. However, unlike a permanent magnet that needs no power, an electromagnet requires a continuous supply of current to maintain the magnetic field.Electromagnets are widely used as components of other electrical devices, such as motors, generators, relays, loudspeakers, hard disks, MRI machines, scientific instruments, and magnetic separation equipment. Electromagnets are also employed in industry for picking up and moving heavy iron objects such as scrap iron and steel.