Jeruti

Excuse me, I have a technical question to ask. My electric linear brake emits a continuous high-frequency buzzing sound after being energized and engaged, similar to a mosquito's buzz. The sound pressure level isn't high, but it's extremely disturbing. Using a stethoscope, I located a tiny residual air gap on the electromagnet's engagement surface. The armature vibrates at a high frequency under the pulsating AC magnetic force. Adjusting the air gap reduces the buzzing, but after a few days of operation, the air gap changes again, possibly due to wear. I'm considering adding a silencing shim, but I'm worried about increasing the engagement time. Could I connect a DC holding circuit to the electromagnet control circuit to eliminate the AC pulsation? Or could I use a soft magnetic material with a short-circuit ring? Thank you in advance for all your help and guidance.