Derived directly from the well-known Maxwell's equations 2, the equivalent magnetic charge model and equivalent magnetizing current are widely used to obtain, either analytically or numerically, the magnetic field and magnetic force of permanent magnets 3.
Generation of controlled magnetic fields has many applications, including spacecraft, magnetic resonance imaging, bioelectromagnetic research, and nondestructive testing (NDT). Some devices, such as sensors, actuators, and speakers, are built with magnets, coils, or both 1.Įlectromagnetic coils are very important in modern medical and electrical sensors and systems.
However, some devices, such as magnetic couplings, are made of permanent cylindrical magnets, while others, such as transformers, are made of coils. Magnetic devices used in electrical engineering require magnets or coils.
