1. Magnetic field shielding

Wherever there is a change in current, there is a change in magnetic field. In our living space, magnetic field interference often occurs. For example, in the vicinity of electrified railways, elevators in high-rise buildings, electric welding equipment in workshops, electroplating tanks, electric arc furnaces and induction heating furnaces, etc., when they work, they are accompanied by large current changes, resulting in changes in magnetic fields. Because the frequency of these disturbances is very low (usually 50Hz or 60Hz power frequency AC, some even direct current), these problems are very tricky to deal with.

2, magnetic field shielding principle