Category: MAGNETIC CIRCUITS

Application of Permanent Magnet Motor

Application of Permanent Magnet Motor: Application of Permanent Magnet Motor are given in Table 2.1. These properties are: residual flux density Br, coercive magnetizing force Hc maximum energy stored (BH)max and resistivity. Type A material is cheap but heavy, and suitable for low-rated production-run motors. Types B and C materials are hard and can be […]

Permanent Magnet Definition

Permanent Magnet Definition: The Permanent Magnet Definition is an important excitation source (life long) commonly employed for imparting energy to magnetic circuits used in rotating machines and other types of electromechanical devices. There are three classes of permanent magnet materials (or hard magnetic materials) used for permanent magnet dc (PMDC) motors: Alnicos, ceramics (ferrites) and […]

Hysteresis Loss and Eddy Current Loss

Hysteresis Loss and Eddy Current Loss: When a magnetic material undergoes cyclic magnetization, two kinds of power losses occur in it Hysteresis Loss and Eddy Current Loss which together are known as core-loss. The core-loss is important in determining heating, temperature rise, rating and efficiency of transformers, machines and other ac run magnetic devices. Hysteresis […]

Energy Density Formula

Energy Density Formula: The Energy Density Formula of transformers, ac machines and several other electromagnetic devices are excited from ac rather than dc sources. With ac operation, inductance is effective even in steady-state operation. Often, the flux is determined by the impressed voltage and frequency, and the magnetization current has to adjust itself in accordance […]

Magnetically Induced Emf and Force

Magnetically Induced Emf and Force: Magnetically Induced Emf and Force – Faraday’s law of induction, which is the integral form of the fourth Maxwell’s equation, is given as The integrated form of Eq.(2.15) for a coil of N turns is The positive direction of current in the coil is that direction which establishes positive flux […]

Magnetic Properties of Materials

Magnetic Properties of Materials: Magnetic Properties of Materials – From the magnetic point of view a material is classified according to the nature of its relative permeability (μr). All nonmagnetic materials are classified as paramagnetic ,μr slightly greater than 1, and diamagnetic, μr slightly less than 1. For all practical purposes, μr of these materials […]