Wiki article · Collection 03

Coil Vibration and Stress

Engineering reference on Coil Vibration and Stress for wireless power system design, integration, and deployment.

6 minArticle 44/50Coil Design

Coil Vibration and Stress — educational diagram — Fig.: Educational diagram for “Coil Vibration and Stress”.

Coils experience vibration from vehicle motion, magnetic forces between TX and RX during high-current operation, and magnetostrictive noise in ferrite and steel. Floor pads see traffic vibration. Repeated stress can fatigue wire enamel, crack ferrite, or debond potting from aluminum spreaders.

Audible coil whine is a symptom — even without noise, micro-movement increases Rac intermittently and confuses diagnostics.

01Mitigation

Potting hardness tuned to damp resonance without cracking ferrite.
Mechanical clamping of ferrite tiles independent of potting.
Flex relief on coil leads exiting the pad.
Avoid loose ferrous covers that rattle in the field.

Coil Vibration and Stress — supporting diagram — Fig.: Supporting illustration for “Coil Vibration and Stress”.

02Test

Sine and random vibration per vehicle or pad install standard. Monitor L and Rac before/after vibration campaign. Optional acoustic test in anechoic or quiet chamber for whine acceptance criteria on premium indoor AMRs.

03Design for service

Strain relief prevents lead fracture at solder joint.
Document torque on mechanical fasteners — loosening changes gap.
Inspect potting delamination after known impact events.