Electrostatic speaker - QuickField simulation example
Electrostatic speaker consists of a pair of stator plates connected to the audio amplifier and a metallized diaphragm connected to a high voltage source.
How to find electric field and force in electrostatic loudspeakers?
Answer Typical applications Geometry
Given
Task
Solution
Results
Reference: Wikipedia: Electrostatic loudspeaker
Engineering question
Set up an axisymmetric QuickField Electrostatics problem for an electrostatic loudspeaker and evaluate electric field and force from computed field results.
electrostatic loudspeakers, high-voltage audio transducers, diaphragm speaker actuators
Download
Simulation problem
Problem Type
Axisymmetric multiphysics problem of electrostatics coupled to Stress analysis.
Relative permittivity of diaphragm ε = 3;
Diaphragm thicnkess 40μm;
Power supply voltage V+ = 600 V
Amplifier output voltage V~ = 100 V, peak.
Calculate the electric force acting on the diaphragm and diaphragm mechanical displacement.
To calculate the maximal displacement we should apply the peak value of amplifier voltage. In the model left stator has the potential of -½*|V~| = -50 V, and right stator has the potential of ½*|V~| = 50 V.
The forces distribution is then passed to mechanical problem to calculate the displacement.
Electric force acting on the diaphragm is -0.014 N per 12.5 cm² of diaphragm area. Diaphragm central part displacement is 0.3 mm.
Video
Related examples