Most of the magnetizing machines used in loudspeaker production plants need to work continuously. Once damaged, the production will be interrupted. Therefore, it is necessary to magnetize and operate continuously for a long time without damage.
(1) the main reason for the damage of the magnetizer coil is the turn to turn short circuit of the coil:
When the magnetizing machine is used, the coil temperature rises too high, exceeding the maximum allowable operating temperature of the insulating layer of the conductor, and the insulation strength decreases, resulting in an inter turn short circuit after the breakdown of the insulation. Because of the breakdown resistance is greater than the wire resistance, breakdown point will overheat fault of interturn short circuit to expand effective excitation number decreased, magnetizing field decreased.
Solution: improved magnetizing machine design, improve the magnetic circuit efficiency of magnetizing machine, reasonable selection of wire coil current density, improve the heat dissipation condition, the magnetizing machine work cycle when meet user needs, not to exceed the maximum working temperature of the coil temperature rise allows wire insulation.
(two) the coil is not fixed. The electromagnetic force acting on the wire is the current through the wire, the flux density at the position of the wire, the length of the wire, the wires that are not fixed, vibrate when they are magnetized, because of the electromagnetic force. The result of vibration will destroy the insulation of the wire, resulting in the turn to turn short of the coil, and decrease the magnetizing field.
