How can we solve the problem of excessive noise when the electromagnetic coil is energized?

Question: when the electromagnetic coil is energized, the noise is too large. How can we solve it?
Answer: the origin of the big problem of the noise of the electromagnetic coil is the pilot head part, the pilot head has the difference between AC and DC. The pilot component of the AC needs to add the magnetic ring on the static iron core, which can effectively control the noise problem.