Magnetostatic speaker - QuickField simulation example
Force acting on the current-carrying planar diaphragm of a magnetostatic speaker placed in the magnetic field produced by a permanent-magnet array.
How to calculate the force acting on a magnetostatic speaker diaphragm?
Answer Typical applications Geometry
Given
Task
Solution
Results
Reference: Wikipedia: Magnetostatic loudspeaker
Engineering question
Use a DC-magnetic model for the peak strip current, since peak force is frequency-independent, and integrate the magnetic force acting on the diaphragm strip.
planar magnetostatic speakers, flat-panel loudspeakers, permanent magnet audio drivers
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Simulation problem
Problem Type
Plane-parallel problem of DC magnetics.
Permanent magnet coercive force HC = 500 kA/m;
Current I = 0.1 A
Lz = 1 m
Calculate force acting on a diaphragm.
In real device the AC current flows in the strip. Peak force value depends only on the current magnitude, and does not depend on frequency. This allows us to simulate DC problem instead of AC to calculate peak force value.
Due to model symmetry we can reduce simulation domain.
Magnetic force acting on a strip of the diaphragm is 0.033N per 1m of strip z-length.
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