Reviewing magnetism

MAGNETIC CIRCUITS REVIEW

1 Z Jan Bochynski

NYU EE3824 Electrical Energy Conversion Systems

February 12, 2013

Week 3rd Class 5

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1. The hysteresis loop has symmetry. 2. For a given field intensity H exist two B values, one for increasing

H (or current) and the second for decreasing H or current. 3. To demagnetize material we need to put it through magnetization

cycles while each of the cycle has gradually decreasing flux (current) intensity.

4. The maximum flux density in a ferromagnetic material is a function of temperature. As the temperature increases, the saturation flux density decreases. In addition, beyond a certain temperature (called the Curie point) the material loses its ferromagnetic properties.

5. Different materials have different saturation flux densities. This factor will affect the size of the core needed in an electromagnetic device.

Hysteresis Properties

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Magnetic Circuits Samples