Dynamic loudspeaker inductance - QuickField simulation example
Engineering question
How to find dynamic loudspeaker coil inductance magnetic circuit?
Answer
Set up an axisymmetric QuickField DC Magnetics problem for a dynamic loudspeaker magnetic circuit and evaluate coil inductance from computed field results.
Typical applications
dynamic loudspeakers, voice coil actuators, electroacoustic transducers
Download
- Download simulation files (files may be viewed using any QuickField Edition).
Simulation problem
Problem TypeAxisymmetric multiphysics problem of DC magnetics coupled to AC magnetics.
Geometry
Given
Permanent magnet coercive force Hc = 500 kA/m
Coil current i = 0.1 A
Magnetic permeability of core - B-H curve:
Task
Calculate the loudspeaker coil inductance with respect to core saturation.
Solution
Magnetic state of the core affects the inductance value. The problem is solved in two steps. First the magnetic field of the permanent magnet is simulated and the core permeability (magnetic state) is calculated. The magnetic state is then imported in the second problem. In the second problem the magnetic field of the coil is simulated and the inductance is calculated.
Result
Core saturation caused by permanent magnet. Coil inductance L = 1.5 mH.
Video
- Dynamic loudspeaker. Watch on YouTube