(2) Alternating magnetic field: that is, the magnitude and direction of the magnetic field change with time. Such as different polarity gyromagnetic machines, electromagnetic therapeutic machines, alternating magnetic field magnetic beds, magnetic chairs, etc. It belongs to alternating magnetic field, also known as dynamic magnetic field.
(3) Pulsating magnetic field: that is, the magnetic field intensity changes regularly with time. But the direction remains the same. Like the famous magnetic pole rotating magnetic motive and magnetic massager, it also belongs to dynamic magnetic field.
(4) Pulsed magnetic field. The intensity of this magnetic field not only changes with time, but also suddenly appears and disappears. There is often a gap time before repetition, and the length of the gap time is related to the pulse frequency. If the frequency is low and the pulse width is small, each gap time is long. It uses intermittent oscillator to generate intermittent pulse current, which flows into the coil of electromagnet to generate various forms of pulse magnetic field. Such as a pulse electromagnetic therapy machine.