The specific introduction of the B demagnetization curve of the permanent magnets

　　What is notable is that, if the B magnet demagnetization curve is not a straight line, then the permanent magnets' reply permeabilityμ rec. has different values at different operating points, and how to design the most stable working condition is showed very important.

　　On the define permanent magnets' demagnetization curve, when J=0.9Jr J, the reverse magnetic field size is Hk, Hk/jHc can intuitively represent the J magnet demagnetization curve square degree. For the sintered NdFeB magnets with high jHc, jHc is greater than bHc, when the reverse magnetic field is greater than bHc but less than jHc, the corresponding B demagnetization curve has entered the third quadrant.

　　By the (1-1 ) type, we can know that if the J magnet demagnetization curve is a line, the third quadrants of the B demagnetization curve also keep in line, the magnet? Rec is still remained a relatively small value, after the reverse magnetic field is canceled, magnet working point can still return to the original position.