In terms of magnetization methods
1. Limitations of square wave magnetization
With the development of product technology, for new types of ferrite magnet materials, the square wave magnetization method gradually fails to meet the requirements. During the magnetization process, it is unable to make the magnetic force of the magnets reach a fully saturated state, and the magnetic field lines are unevenly distributed. This is because of the characteristics of the square wave itself. It contains odd harmonics of the sine wave, and its waveform complexity is relatively high. As can be seen from the Fourier expansion formula (where refers to the amplitude of the square wave), the square wave is composed of multiple frequency components and is less pure compared to the sine wave. Such complex frequency components may lead to an insufficiently concentrated and precise magnetic field effect during the magnetization process, preventing the magnetic domains inside the ferrite magnets from being completely aligned and thus failing to achieve saturated magnetization.
2. Advantages and applicable situations of sine wave magnetization
For Foshan ferrite magnets used in brushless motors, the sine wave magnetization method is often adopted. Because the sine wave is a relatively regular waveform, the distribution of magnetic field lines and magnetic flux is relatively uniform and precise, and the direction of the magnetic field lines is relatively consistent. For example, in the brushless motors of electric vehicles, when it is necessary to control the speed and shift gears during the operation of the motor, a sine wave controller is used. After being magnetized by the sine wave, the magnets have a relatively uniform induction with the coils, making the brushless motors operate relatively stably. This shows that the magnetization method plays a crucial role in the performance of the magnets. If the magnetization method is not suitable for the application scenarios of ferrite magnets, it may lead to unsaturated magnetization.
In terms of magnetization equipment
The selection of a magnetizer is of vital importance. Whether it is sine wave or square wave magnetization, an appropriate magnetizer is required to achieve it. If the performance of the magnetizer is poor, such as insufficient magnetic field strength output and uneven magnetic field distribution, even if an appropriate magnetization waveform is selected, it may still lead to unsaturated magnetization of ferrite magnets. For example, although insufficient voltage of the magnetizer has a certain impact on magnetization saturation, compared with that, the inappropriate selection of the magnetization method is a more significant reason. When dealing with magnet products with relatively high magnetization requirements, it is necessary to comprehensively consider factors such as the type and parameters of the magnetizer to ensure that sufficient magnetic field strength and an appropriate magnetic field waveform can be provided to achieve saturated magnetization.
