comment on B-H curve of the transformer
In practice, all magnetic materials, once magnetized, retain some of their magnetization even when the magnetizing force is reduced to zero. This effect is known as 'remanence' and results in the B-H curve for the material exhibiting a response to a decreasing magnetizing force that is different to the response to an increasing magnetizing force. The slope of the B-H curve, the saturation level, and the size of the hysteresis loop are dependent on the type of material used, Hysteresis loss is the result of cycling the magnetic material along its B-H curve. It represents the energy taken as the applied voltage, aligns magnetic dipoles first in one direction, and then in the other. The loss increases with the area of the B-H curve enclosed. As the material is driven closer to saturation, both the area within the curve, and the corresponding energy loss each cycle, increase substantially.
OK, I'll make some comments. The B-H curve is a pair of squiggly lines The flux B is the integral of volts wrt time multiplied by 10^8/(core area times turns) The width of the field H, in oersteads is wider when the flux is changed faster. This goes up typically by the 1.4 power in ferrites. It is also wider for larger total flux. This goes up typically by the 2.8 power in ferrites.
